Keywords: Dengue
Wolbachia wMel and wAlbB strains differentially impact the vector competence of Aedes aegypti with a Brazilian genetic background for DENV-1 virus
35484Martins, C.B., David, M.R., Couto-Lima, D. et al., Parasites Vectors, 2026-03-05 08:32:23.
Aedes aegypti mosquitoes infected with the endosymbiotic bacterium Wolbachia pipientis have been released as a sustainable strategy to mitigate arbovirus transmission. Among the strains successfully deployed, wMel and wAlbB have shown promising blocking effects against dengue virus (DENV). However, the strength of viral inhibition depends on Wolbachia density within mosquito tissues, the genetic backgrounds of both host and virus, and the viral dose. In this study, we aimed to investigate the vector competence for DENV-1 of Ae. aegypti with Brazilian genetic background infected with wMel or wAlbB. A total of 493 wild and wMel- and wAlbB-infected mosquitoes were orally challenged with low (5 × 104 FFU/mL) and high (5 × 105) titers of DENV-1. Relative Wolbachia density was measured by quantitative polymerase chain reaction (qPCR), and viral infection in mosquito bodies and saliva was assessed by qPCR with reverse transcription (RT-qPCR). Transmission potential was tested through saliva microinjection into susceptible mosquitoes. The infection prevalence and viral loads in mosquito bodies were analyzed at 7, 14, and 21 days post infection (dpi).Both Ae. aegypti groups infected with wMel and wAlbB had reduced (albeit distinct) DENV-1 infection and transmission relative to wild type mosquitoes. wMel-infected mosquitoes exhibited less abundant bacteria in their bodies but a greater degree of DENV-1 inhibition compared with those carrying wAlbB, indicating that DENV-1 blocking is strain specific rather than Wolbachia density-driven. Moreover, we observed that Wolbachia had a protective effect on mosquitoes by decreasing the DENV-1 loads in their bodies, but with a constant presence of virus. Viral transmission rates in the saliva were similar among wild and wMel- and wAlbB-infected mosquitoes at 7 and 14 dpi but lower in wMel and wAlbB mosquitoes at 21 dpi. The similar DENV-1 loads in mosquito bodies over time (7, 14, and 21 dpi) infected with either the wMel or wAlbB strain, regardless of the viral titer of the infectious blood meal, suggest that Wolbachia may have a maximum pathogen-blocking capacity beyond which additional virus suppression cannot be achieved. The viral suppression only after 21 dpi in the saliva raises concerns and warrants further investigation, as females may transmit before Wolbachia blockage becomes effective. While wAlbB may exhibit comparable DENV-1 blocking to wMel, its enhanced thermal tolerance makes it epidemiologically relevant in tropical regions. Continuous monitoring of Wolbachia dynamics and DENV genomic variation in the field remains essential to evaluate long-term effectiveness and detect potential adaptive viral responses.
Locally Acquired Dengue in Townsville, Australia, 2024–2025: An Outbreak Report in a Non-Endemic Region with wMel Wolbachia-Infected Aedes aegypti
35533Thompson, K., Lyons, S., Malone, K., Fryk, J., Pyke, A., & Murton, K., Tropical Medicine and Infectious Disease, 11. 2026-02-26 19:11:49.
During the 2024/2025 wet season, Townsville had its first sustained autochthonous outbreak of dengue disease caused by dengue virus type 2 (DENV-2), the second locally transmitted outbreak of dengue since 2014 following the introduction of wMel strain Wolbachia-infected mosquitoes, a control strategy for dengue virus (DENV) and other Aedes-transmitted arboviruses. In comparison to two recorded locally acquired cases of dengue in 2020, the 2024/2025 outbreak resulted in sixteen cases in two inner-city suburbs of Townsville during the wet season associated with higher-than-average rainfall. This second dengue outbreak since 2014 highlights that Townsville and other north Queensland communities where Wolbachia mosquito programs have been deployed remain vulnerable to DENV incursions and local disease outbreaks despite the apparent high coverage of Wolbachia-infected mosquitoes. Whilst these control strategies have likely contributed to a reduction in the number and frequency of autochthonous DENV outbreaks in north Queensland, ongoing maintenance and monitoring of Wolbachia-infected mosquito coverage is necessary, together with timely review and improvement in dengue awareness and prevention health promotion activities in the community.
Mathematical modelling of Wolbachia replacement in Aedes aegypti for dengue control: a scoping review
35445Katie Tiley, Laith Yakob, Kathleen O'Reilly, Oliver Brady, Proc Biol Sci, 293. 2026-02-12 17:52:03.
Wolbachia replacement in dengue virus vectors is a promising tool for controlling transmission, and models can explore its potential in novel and complex scenarios. We analyse how research questions in Wolbachia replacement modelling have developed over time and in response to empirical findings. A scoping review was conducted of Wolbachia replacement models. For each study, we extracted research questions, key findings and modelling methodology and thematically categorized research questions. From 726 search results, 115 studies met inclusion criteria. Four themes were identified: identifying key Wolbachia characteristics (n = 61, 53.0%), investigating effects of environmental heterogeneity (n = 21, 18.3%), estimating epidemiological impact (n = 25, 21.7%) and exploring Wolbachia replacement in combination with other arboviral control measures (n = 8, 7.0%). Models identify cytoplasmic incompatibility (CI) and maternal transmission (MT) as key for fixation success. However, less than 20% (n = 6) of studies parameterize CI and MT using empirical sources. Although models agree outbreaks may occur with fixation, few explore epidemiological outcomes of heterogeneous Wolbachia fixation or combined vector control. These findings highlight the need for empirical parameterization and incorporating environmental complexity for models to remain insightful for decision-making. Policymakers would benefit from future models exploring heterogeneous coverage and combined control strategies, given evidence of context-specific outcomes and diverse control tools.
Dengue Suppression by Male Wolbachia-Infected Mosquitoes
35443Jue Tao Lim, Ph.D., Chee-Seng Chong, Ph.D., Chia-Chen Chang, Ph.D., et al., New England Journal of Medicine, 2026-02-12 17:46:04.
Wild-type female Aedes aegypti mosquitoes that mate with male A. aegypti mosquitoes that have been infected with the wAlbB strain of Wolbachia pipientis bacteria produce nonviable offspring owing to cytoplasmic incompatibility. Repeated releases of wolbachia-infected males can potentially suppress wild-type mosquito populations and reduce the risk of dengue virus infection. We conducted a trial involving the release of male A. aegypti mosquitoes infected with the wAlbB strain of wolbachia bacteria for the control of dengue in Singapore, a tropical city-state. In this cluster-randomized trial with test-negative controls, we divided 15 geographic population clusters into two groups: 8 clusters received deployments of male wolbachia-infected mosquitoes (intervention clusters) and 7 clusters received no deployments (control clusters). The primary end point was the diagnosis of symptomatic dengue virus infection of any severity caused by any serotype of the virus, as measured by the odds ratio for the distribution of wolbachia exposure among laboratory-confirmed reported dengue cases as compared with test-negative controls. A total of 393,236 residents lived in the intervention clusters, and 331,192 lived in the control clusters. Adult wild-type A. aegypti populations were suppressed across the intervention clusters. The baseline average abundance of the mosquitoes (number of adult female mosquitoes trapped divided by number of traps) was 0.18 and 0.19 in the intervention and control clusters, respectively; from 3 months after the initiation of the intervention until the end of the 24-month trial period, the average abundance was 0.041 and 0.277, respectively. In the intention-to-treat analysis at 6 months or more, the percentage of residents in the intervention clusters who were dengue-positive was lower than that in the control clusters (354 of 5722 tests [6%] vs. 1519 of 7080 tests [21%]). The protective efficacy of the intervention, calculated as (1−odds ratio)×100, ranged from 71 to 72% with 3 to 12 months or more of wolbachia mosquito exposure, as represented by odds ratios of 0.28 to 0.29. Release of sterile wolbachia-infected male A. aegypti mosquitoes reduced vector populations and the risk of dengue infection in Singapore.
Space Coast releases X-rayed skeeters to take bite out of dengue
35410Jim Waymer, Florida Today, 2026-01-29 10:40:25.
The Space Coast has unleashed 'nuked' skeeters in a new biological bid to neuter dengue fever. Last year, Brevard saw its first locally caught cases of the tropical disease and wound up with the most in Florida. In response, the county decided to let loose thousands of X-rayed male mosquitoes to zap the insect's next generation. Turns out an adult skeeter can survive X-ray doses more than 10 times what would kill humans. Unlike humans, once mature, most mosquito cells stop dividing, so radiation rushing through has fewer chances to distort most of its DNA. But X-rays will tear up the insect's reproductive genes enough to render the male mosquito sterile. That's among the reasons mosquito-control officials assure this time-tested method is safe and environmentally friendly. They emphasize that it's not anything like the much-more controversial gene modification of mosquitoes used in recent years in the Florida Keys. "When we're releasing, there's no voodoo," said Joe Faella, Brevard's mosquito control director.
Wolbachia mosquito release cuts dengue cases 50–80 percent
35437Mohamad Al As, Zaf Seraj, New Straits Times, 2026-01-27 18:26:15.
The release of Wolbachia-infected Aedes mosquitoes has led to a 50 to 80 per cent drop in dengue cases in several outbreak areas in Selangor, the Dewan Rakyat was told. Health Minister Datuk Seri Dr Dzulkefly Ahmad said public health studies conducted during the early phase of the programme showed encouraging results. "During the early phase of implementation, the results of public health studies in six dengue outbreak localities in Selangor showed a reduction in dengue cases between 50 per cent and 80 per cent compared with control localities," he said in a written parliamentary reply last night. He was responding to Mohd Hasnizan Harun (PN-Hulu Selangor), who asked whether the ministry has conducted comprehensive environmental and public health impact studies related to the release of Wolbachia-infected mosquitoes. Hasnizan also asked about continuous monitoring mechanisms to ensure long-term safety. Dzulkefly said the early assessments also examined the interaction between Wolbachia-infected Aedes mosquitoes and the existing mosquito population in the environment.
Color-coded mosquitoes safely enables male-only releases to combat Dengue and Zika
35369Joshua Shavit, The Brighter Side of News, 2026-01-16 11:13:48.
Across much of the world, a tiny striped insect shapes whether families stay healthy or get sick. The Asian tiger mosquito carries Dengue, Zika and Chikungunya, and traditional control efforts often struggle to keep up. A new genetic trick that literally changes how these mosquitoes look could help tip the balance in your favor. Only female mosquitoes bite and pass on viruses. Males drink nectar, not blood. Many modern control programs release large numbers of males that are sterile or carry a trait that reduces survival in the next generation. When those males mate with wild females, fewer disease-carrying offspring survive. There is one big catch. These programs must release only males. If too many females slip through, they will still bite, still spread disease and may even weaken the program. Today, most facilities separate sexes by size during the pupal stage. That work is tedious, hard to automate and far from perfect. Researchers led by Doron Zaada and Prof. Philippos Papathanos at the Hebrew University of Jerusalem set out to remove that bottleneck. Their idea was simple and bold. Make male and female mosquitoes so visually different that machines, or even the human eye, can sort them at a glance. The team focused on Aedes albopictus, also known as the Asian tiger mosquito. It is aggressive, invasive and a major target for control programs worldwide. In their study, the scientists describe a “Genetic Sexing Strain” that turns sex into a visible trait. They used CRISPR gene editing to break a gene called yellow that controls dark pigment in the mosquito body. When this gene is disrupted, the insects turn pale, almost albino. The group then restored normal dark pigmentation only in males by linking a working copy of the yellow gene to nix, a sex-determining gene. Nix acts like a master switch. When it turns on in a mosquito, the insect develops as a fertile male, even if it started out genetically female. By tying yellow to nix, the team created a line in which all males are dark and all females remain pale. “This produces an engineered sex-linked trait in mosquitoes that uses the insect’s own genes,” said Prof. Papathanos. “By understanding and controlling the sex determination pathway, we were able to create a system were males and females are visually different at the genetic level.”
Rethinking the future of mosquito control
35341Kabirul Bashar, Dr Zonaed Siddiki. Dr Zonaed Siddiki, et al., Dhaka Tribune, 2025-12-17 11:37:26.
Bangladesh is once again in the grip of a severe dengue and chikungunya crisis in 2025. Hospitals are overwhelmed, fever wards are full, and doctors are working tirelessly. Families live in fear of mosquito bites, while daily news reports chronicle rising infections and deaths. As of December 16, 2025, the Directorate General of Health Services (DGHS) has reported more than 100,000 confirmed dengue cases and 409 deaths. However, this figure represents only the tip of the iceberg, as it reflects data solely from hospitalized patients, specifically from 77 hospitals in Dhaka and reports from 64 civil surgeon offices. A substantial number of dengue patients are receiving treatment at home or in various small and large hospitals and clinics that are not included in the official count. This underscores the overwhelming pressure on the country’s health system. At the same time, the Institute of Epidemiology, Disease Control and Research (IEDCR) has recorded a resurgence of chikungunya, reporting 337 suspected cases, 153 of which were laboratory-confirmed in Dhaka between January and May 2025. Researchers estimate that the true number of chikungunya infections this year may be close to one hundred thousand. As chikungunya testing is available only in a limited number of major hospitals in Dhaka, many cases remain undiagnosed and unreported.
Heterogeneity in inhibition of genetically diverse dengue virus strains by Wolbachia
35165Afeez Sodeinde, Emilie Finch, Ke Li, et al., bioRxiv, 2025-09-26 13:29:40.
The release of Aedes aegypti mosquitoes transinfected with the virus-inhibiting Wolbachia bacterium has the potential to reduce the burden caused by dengue virus (DENV). However, the robustness of this control strategy across the wide genetic diversity of DENV remains unknown. Here, we systematically tested two commonly used Wolbachia strains (wAlbB and wMelM) for their ability to inhibit 60 genetically diverse DENV isolates spanning all four serotypes. We found stronger inhibition by wMelM (median relative dissemination: 0.04) than wAlbB (median relative dissemination: 0.19). Furthermore, while we found substantial heterogeneity in inhibition across DENV isolates, we found that more DENV-3 isolates were weakly inhibited (median relative dissemination: 0.47 for wAlbB and 0.39 for wMelM) compared to the other serotypes (median relative disseminations: 0.10-0.18 for wAlbB and 0-0.11 for wMelM). Using transmission dynamic models, we further showed that differential Wolbachia inhibition results in increased probability of reemergence, particularly in high transmission intensity settings, with strong selection for DENV strains that have higher relative dissemination in mosquitoes. Our work highlights the importance of considering DENV genetic diversity, including the long-term risk of selection, in Wolbachia-based control interventions.
Suppression of Aedes albopictus in Sri Lanka using the Sterile Insect Technique (SIT) with a sustained effect
35157Menaka Hapugoda, Nilmini Silva Gunawardene, Tharaka Ranathunge, Sudath Samaraweera, K. Karunathilake, Bazoumana B.D. Sow, Gayan Parakrama Withanage, Indika Weerasinghe, Hamidou Maiga and Jeremy Bouyer, Parasite, 32. 2025-09-22 10:50:08.
Dengue fever remains a significant public health concern in Sri Lanka, leading to recurrent epidemics and imposing substantial socio-economic burdens. This study aimed to assess the efficacy of the Sterile Insect Technique (SIT) against Aedes albopictus (Skuse), the predominant dengue vector in the country, through a pilot field trial of an Integrated Vector Management (IVM) strategy including the SIT. The pilot trial was conducted in the Gampaha district, which reports the second-highest number of dengue cases in the country. A total of 3,300,000 sterile males, exposed to a 50 Gy radiation dose, were released over 33 weeks (100,000/week) within a 30-hectare release area. Entomological assessments were conducted at 115 trapping stations over a period of 71 weeks (October 2020–August 2022). Induced sterility of 98.16% in mosquito eggs was reached within the release area as compared to the control area (binomial generalized linear mixed model, deviance 2.408, df = 2, p = 0.016), indicating a notable impact of the SIT. The trial achieved nearly 98% suppression of adult vector mosquitoes, with a sustained suppression effect for 13 weeks post cessation of releases. These findings suggest that SIT can be effectively integrated as a potential additional tool into the future IVM strategy in Sri Lanka.
How billions of hacked mosquitoes and a vaccine could beat the deadly dengue virus
35143Lucila Pinto, Nature, 645:578-580. 2025-09-17 14:21:03.
Last month, a parade of vehicles wound its way through three cities in Brazil, releasing clouds of mosquitoes into the air. The insects all carry a secret weapon — a bacterium called Wolbachia that lowers the odds that the mosquitoes can transmit the dreaded dengue virus to humans. These infected mosquitoes are the latest weapon in Brazil’s fight against dengue, which infects millions of people in the country each year and can be fatal. A biofactory that opened in the town of Curitiba in July can produce 100 million mosquito eggs per week — making it the largest such facility in the world. The company that runs it, Wolbito do Brasil, aims to protect about 14 million Brazilians per year through its Wolbachia-infected mosquitoes. That will come as welcome news for the Brazilian health officials battling the rapidly growing threat of dengue. In 2024, the country experienced its worst outbreak yet: with 6.6 million probable cases and more than 6,300 related deaths. This year’s outbreak, although less severe, is also one of the highest on record, with 1.6 million probable cases so far (see ‘Dangerous outbreaks’). And the problem is spreading. Argentina, Colombia and Peru also experienced record-breaking outbreaks in 2024 and have seen a sustained increase in cases in recent years. Across Latin America and the Caribbean, deaths from dengue last year totalled more than 8,400 and the global figure reached more than 12,000 — the highest ever recorded for this disease.
Nature goes inside the world’s largest ‘mosquito factory’ — here’s the buzz
35120Adam Levy & Mariana Lenharo, Nature, 2025-09-08 08:31:27.
Raising mosquitoes to tackle disease might sound like an odd concept, but that’s what a facility in Brazil is aiming to do. Millions of mosquitoes are produced there every week, but these insects carry harmless Wolbachia bacteria that curbs their ability to spread deadly human viruses. Nature reporter Mariana Lenharo visited the facility and told us all about her experience in this Podcast Extra.
This is the world’s largest ‘mosquito factory’: its goal is to stop dengue
35109Mariana Lenharo, Nature, 2025-09-03 09:20:02.
When biologist Antonio Brandão tells people that he works at a mosquito factory, they are often baffled. Why would you make more mosquitoes?, he recalls people asking. “We have enough of them.” But once he explains that the laboratory-raised insects can help to stop the spread of dengue — which strikes hundreds of thousands in Brazil each year with fever, headache and bone pain — they come around. Brandão is the production manager, not at just any mosquito factory, but at the world’s largest, located in the southern Brazilian city of Curitiba. Launched in July, the facility is expected to produce 100 million eggs a week from the mosquito Aedes aegypti. However, unlike wild A. aegypti, the main transmitter of dengue virus, those churned out by the factory carry a harmless Wolbachia bacterium that curbs the insects’ ability to spread viruses including dengue and Zika. The idea is to release the modified mosquitoes, which researchers call wolbitos, into cities in Brazil, where they will mate with their wild counterparts and the females will pass the bacterium on to their offspring, gradually converting the local population. The wolbito strategy, which is being spearheaded by the non-profit World Mosquito Program (WMP), has already shown success in Colombia, Indonesia and at home: in the Brazilian city of Niterói in the southeast, dengue cases dropped by 69% in areas where Wolbachia-carrying mosquitoes were released, compared with areas where they weren’t1. Brazil’s federal government has adopted the approach to fight dengue infections — which surged to a record 6.5 million confirmed cases in the country last year — alongside other preventive measures such as vaccines.
Long-Term Durability and Public Health Impact of City-Wide wMel Wolbachia Mosquito Releases in Niterói, Brazil, During a Dengue Epidemic Surge
35107Anders, Katherine L., Gabriel Sylvestre Ribeiro, Renato da Silva Lopes, Pilar Amadeu, Thiago Rodrigues da Costa, Thais Irene Souza Riback, Karlos Diogo de Melo Chalegre, Wesley Pimentel de Oliveira, Cátia Cabral da Silva, Marcos Vinicius Ferreira Mendes B, Tropical Medicine and Infectious Disease, 10. 2025-09-02 18:57:03.
In 2024, the Americas experienced the largest dengue outbreak on record and Brazil was among the worst affected countries, reporting 6.6 million cases and 6200 deaths. We report the long-term entomological and epidemiological effectiveness of city-wide deployment of wMel-strain Wolbachia-infected Aedes aegypti in Niterói, a city of half a million people in Rio de Janeiro state, where Wolbachia releases across three-quarters of the urban population in 2017–2019 were expanded to remaining populated areas in 2023. wMel was durably established at ≥95% prevalence in Ae. aegypti populations throughout Niterói four years post-release, and up to seven years in the earliest release sites. Notified dengue case incidence in Niterói was 89% lower following Wolbachia releases, compared to the 10-year pre-intervention period of 2007–2016. Dengue incidence in Niterói in 2024, during a period of record high incidence in Brazil and the region, was 374 per 100,000 population, substantially lower than overall in Rio de Janeiro state (1884 per 100,000) and nationwide in Brazil (3157 per 100,000). Our findings show that city-wide Wolbachia coverage in Niterói provided sustained population-level reduction in dengue incidence throughout the five years post-intervention, including during the 2024 epidemic surge, averting an estimated three-quarters of the dengue case burden that may otherwise have been expected in Niterói in 2024.
Genomic Insights into Wolbachia Strain wCin2USA1 Reveal Promising Cytoplasmic Incompatibility Potential and Next-Generation Dengue Biocontrol
35098Istiaque Zaeem, Nurnabi Azad Jewel, Mohimenul Haque Rolin, et al., bioRxiv, 2025-09-01 19:59:21.
Dengue fever is one of the fastest-growing mosquito-borne diseases in the world, causing illness and economic challenges in many countries. Current mosquito control methods, such as insecticides, are often costly, less effective over time, and harmful to the environment. An alternative approach uses naturally occurring bacteria called Wolbachia, which live inside insects. When certain Wolbachia strains are introduced into mosquitoes, they can reduce the insects’ ability to spread viruses like dengue. In our study, we compared the genetic makeup of several Wolbachia strains to identify new candidates that may work better for controlling dengue. We discovered that a strain called wCin2USA1 has strong potential because it shares important features with two strains already used successfully, while also having unique advantages. These include genes that help prevent mosquitoes from reproducing normally when carrying different Wolbachia strains, which can reduce mosquito populations. Our findings suggest that wCin2USA1 could be developed as a new, environmentally friendly tool to help reduce dengue transmission.
Emerging challenges for mosquito-borne disease control and the promise of symbiont-based transmission-blocking strategies
35064Gao H, Hu W, Cui C, Wang Y, Zheng Y, Jacobs-Lorena M, et al., PLoS Pathog, 21. 2025-08-26 17:16:49.
Mosquitoes serve as vectors for a variety of pathogens that cause life-threatening diseases, such as malaria, dengue, Zika, and yellow fever. With the rise of antimalarial drug resistance and a lack of therapeutics or prophylactics for dengue and Zika, current disease control strategies rely heavily on mosquito population management. However, the effectiveness of conventional approaches is increasingly compromised, highlighting an urgent need for innovative tools to combat mosquito-borne diseases. One promising strategy for blocking the transmission of these diseases is to populate mosquitoes with anti-pathogen gut symbionts. Here, we discuss the major challenges facing current mosquito-borne disease control efforts and explore how mosquito gut microbiota-based control strategies may address them. We highlight recent advances that may accelerate field applications and offer perspectives on future directions and the translational potential of symbiont-based strategies for mitigating mosquito-borne disease transmission.
Implications of successive blood feeding on Wolbachia-mediated dengue virus inhibition in Aedes aegypti mosquitoes
34989Johnson, R.M., Breban, M.I., Nolan, B.L. et al., Nat Commun, 16. 2025-07-30 10:55:57.
Wolbachia is a promising strategy to inhibit dengue virus (DENV) transmission by Ae. aegypti mosquitoes. Laboratory studies assessing DENV inhibition by Wolbachia typically have not considered natural frequent mosquito blood feeding behavior. Here, we determine the impact of successive feeding on DENV-2 transmission by Ae. aegypti in the presence or absence of Wolbachia (wAlbB and wMelM strains). We show that successive feeding shortens the extrinsic incubation period (EIP) in wildtype (WT; without Wolbachia) and wAlbB mosquitoes through enhanced dissemination. Feeding empirical data into models showed that successive feeding increases the probability of WT and wAlbB mosquitoes surviving beyond the EIP. Importantly, the more epidemiologically relevant comparison of the odds of wAlbB mosquitoes surviving beyond the EIP relative to WT, reveals a larger impact of successive feeding on WT than wAlbB. This indicates a strong inhibitory effect of Wolbachia even in the context of natural frequent mosquito blood feeding behavior.
Modelling and sensitivity analysis to control dengue through inclusion of genetically modified hybrid mosquitoes
34907Wasim, T., Ismaeel, T., Naseem, A., Abdeljawad, T., & Alqudah, M. A., Mathematical and Computer Modelling of Dynamical Systems, 31. 2025-06-15 18:50:47.
Dengue fever, an ancient yet persistent global health threat transmitted by mosquitoes, remains difficult to control. Recent advances propose genetically modified hybrid mosquitoes as a novel intervention. This study focuses on two primary control strategies: the Sterile Insect Technique (SIT) and genetic sterilization. SIT involves releasing sterile male mosquitoes to reduce populations through unsuccessful mating, while genetic sterilization targets mosquito reproduction or virus transmission capabilities. In our proposed model, modified mosquitoes are included in the susceptible vector compartment, denoted as ℧𝑚. Diagnosis and treatment are modeled with parameters 𝑑1 and 𝑑2. Field and laboratory studies suggest these methods effectively reduce mosquito populations and dengue incidence. A mathematical model is developed to study this strategy’s impact, incorporating the basic reproduction number 𝑅0 and equilibrium analysis. Numerical methods are used to assess system stability and compute sensitivity indices 𝒲ℋ𝜉, ultimately demonstrating the potential for effective dengue control.
Wolbachia: A bacterial weapon against dengue fever- a narrative review of risk factors for dengue fever outbreaks
34743Safaei, S., Derakhshan-Sefidi, M., Karimi, A., New Microbes and New Infections, 65. 2025-04-04 14:53:55.
Arboviruses constitute the largest known group of viruses and are responsible for various infections that impose significant socioeconomic burdens worldwide, particularly due to their link with insect-borne diseases. The increasing incidence of dengue fever in non-endemic regions underscores the urgent need for innovative strategies to combat this public health threat. Wolbachia, a bacterium, presents a promising biological control method against mosquito vectors, offering a novel approach to managing dengue fever. We systematically investigated biomedical databases (PubMed, Web of Science, Google Scholar, Science Direct, and Embase) using “AND” as a Boolean operator with keywords such as “dengue fever,” “dengue virus,” “risk factors,” “Wolbachia,” and “outbreak.” We prioritized articles that offered significant insights into the risk factors contributing to the outbreak of dengue fever and provided an overview of Wolbachia's characteristics and functions in disease management, considering studies published until December 25, 2024. Field experiments have shown that introducing Wolbachia-infected mosquitoes can effectively reduce mosquito populations and lower dengue transmission rates, signifying its potential as a practical approach for controlling this disease.
Genetically modified mosquitoes released in the US: How they can prevent disease outbreaks
34732TOI Lifestyle Desk, Times of India, 2025-04-02 16:42:21.
The menace of mosquito-borne illnesses is growing in the US and the contributing factors range from climate change to their expanding habitats. The solution could lie in genetically modified mosquitoes that hold the capability to effectively control mosquito populations. Recently, genetically modified mosquitoes were released in Florida, US, following the successful trials in Brazil, the Cayman Islands, Panama, and Malaysia, where populations of aedes aegypti dropped by at least 90%. A significant step forward in preventing the deadly mosquito-borne illnesses, the bioengineered male aedes aegypti mosquitoes were introduced into the environment. While these deadly species make up for 4% of the total local mosquito population, they are enough to wreak havoc. It is to be noted that female aedes aegypti mosquitoes are the primary vectors that can transmit dengue, Zika, yellow fever, and chikungunya viruses to humans.
Adjacent spillover efficacy of Wolbachia for control of dengue: emulation of a cluster randomised target trial
34679Lim, J.T., Mailepessov, D., Chong, C.S. et al., BMC Medicine, 23. 2025-03-28 08:29:31.
Matings between male Aedes aegypti mosquitoes infected with wAlbB strain of Wolbachia and wild-type females yield non-viable eggs, thereby suppressing Ae. aegypti abundance in the field. We evaluated the spillover efficacy of releasing wAlbB-infected Ae. aegypti male mosquitoes to suppress dengue in sites adjacent to release sites (spillover sites). The protocol of a two-arm cluster-randomised test-negative controlled trial (cRCT) was specified and emulated using a nationally representative dengue test-negative/positive database of 454,437 individuals reporting for febrile illness to primary or secondary care in public healthcare institutions. Spillover intervention sites were defined by geolocating locations which were adjacent to, i.e. shared geographical borders with, actual Wolbachia intervention sites. We built a cohort of individuals who resided in spillover sites versus a comparator control group who resided in sites which did not receive Wolbachia interventions. We emulated a constrained randomisation protocol used in cRCTs to balance dengue risk between spillover and control arms in the pre-intervention period. We matched individuals reporting for testing in intervention and control groups by calendar time and a high-dimensional battery of sociodemographic, environmental and anthropogenic variables. Intention-to-treat analysis was conducted to estimate the protective efficacy against dengue given spillover Wolbachia exposure. The final cohort consisted of 2354 matched individuals residing in Wolbachia spillover and control sites for at least 3 months in the study period. Compared to the controls, individuals residing in spillover sites for 3 or more months were associated with a 45% (OR: 0.55, 95% CI: 0.42‒0.74) reduction in risk of contracting dengue. Higher durations of spillover Wolbachia exposure also modestly increased protective efficacies. Compared to the control arm, the proportion of virologically confirmed dengue cases was lower in the spillover arm overall and across each subgroup. Protective efficacies were found across all years, age and sex subgroups. Our results demonstrated the potential of Wolbachia-mediated sterility for reducing the risk of contracting dengue even in sites which were not directly treated by the intervention.
Exploiting venom toxins in paratransgenesis to prevent mosquito-borne disease
34533French, S., Da Silva, R., Storm, J. et al., Parasites & Vectors, 18. 2025-02-21 11:33:53.
Mosquitoes are responsible for the transmission of numerous pathogens, including Plasmodium parasites, arboviruses and filarial worms. They pose a significant risk to public health with over 200 million cases of malaria per annum and approximately 4 billion people at risk of arthropod-borne viruses (arboviruses). Mosquito populations are geographically expanding into temperate regions and their distribution is predicted to continue increasing. Mosquito symbionts, including fungi, bacteria and viruses, have desirable traits for mosquito disease control including spreading horizontally and vertically through mosquito populations and potentially colonising multiple important vector species. Paratransgenesis, genetic modification of mosquito symbionts with effectors to target the pathogen rather than the vector, is a promising strategy to prevent the spread of mosquito-borne diseases. A variety of effectors can be expressed but venom toxins are excellent effector candidates because they are target specific, potent and stable. However, the only toxins to be explored in mosquito paratransgenesis to date are scorpine and mutated phospholipase A2. To enhance the scope, effectiveness and durability of paratransgenesis, an expanded arsenal of effectors is required. This review discusses other potential toxin effectors for future paratransgenesis studies based on prior in vitro and in vivo antiparasitic and antiviral studies and highlights the need for further research and investment in this area. In terms of mosquito-borne diseases, paratransgenesis strategies have been developed to target Plasmodium. We postulate the potential to apply this principle to target arboviruses using antiviral toxin effectors.
Implications of successive blood feeding on Wolbachia-mediated dengue virus inhibition in Aedes aegypti mosquitoes
34529Rebecca M. Johnson, Mallery I. Breban, Braiya L. Nolan, et al., bioRxiv, 2025-02-21 10:22:32.
Dengue virus (DENV) is a mosquito-borne virus that poses a continued and increasing threat to public health. A promising strategy to mitigate the burden of DENV is introgression of the virus-inhibiting Wolbachia pipientis bacterium into Aedes aegypti populations in the field. While previous studies on Wolbachia-mediated virus inhibition have typically assessed viral replication following a single bloodmeal, the main vector of DENV, Ae. aegypti, feeds frequently, often biting multiple hosts per gonotrophic cycle and promptly attempting to refeed following egg laying. Previously, we demonstrated that successive blood feeding reduces the extrinsic incubation period (EIP) and shortens the time it takes for a mosquito to be able to transmit viruses to a new host. With this in mind, we investigated the impact of successive blood meals on DENV serotype 2 (DENV-2) in Ae. aegypti in the presence or absence of Wolbachia (wAlbB and wMelM). We found that both WT and Wolbachia transinfected had increased DENV-2 dissemination 7 days post-infection as well as higher body titers of DENV-2 in the double-fed groups. Using these empirical data in a binomial regression model, we estimated that successive feeding increased the probability of WT and Wolbachia transinfected mosquitoes surviving the EIP. When we estimated the odds of surviving the EIP for mosquitoes with Wolbachia relative to WT mosquitoes, successive feeding increased the chances of WT mosquitoes surviving the EIP more than in mosquitoes with Wolbachia, indicating a strong inhibitory effect of Wolbachia even in the context of natural frequent blood feeding behavior. Our work shows that mosquito feeding behavior should be considered when assessing the inhibitory effects of Wolbachia on DENV.
Mitigating dengue transmission in Africa: the need for Wolbachia-infected mosquitoes’ rollout
34211Samson Ogunlade, Adeshina Adekunle, Emma McBryde, Frontiers, 12. 2025-01-07 08:57:15.
Dengue fever is a mosquito-borne viral disease that poses a significant public health concern globally. The disease is primarily transmitted by Aedes aegypti mosquitoes and the range of clinical manifestations vary from flu-like symptoms to more serious conditions such as dengue haemorrhagic fever and dengue shock syndrome. The dengue virus (DENV) infects about 400 million people yearly, of which 50–100 million of those become symptomatic, with over 20,000 deaths. Dengue notifications are increasing in Africa. The continent's tropical and subtropical climatic conditions create a conducive breeding environment for mosquitoes and hence, contribute to the spread of the virus. While recent statistics show that there were 15.7 million reported dengue infections in 2010, recent studies show that dengue cases are on the rise in Africa. This situation presents an increasing threat to public health systems already under pressure from other infectious illnesses. Traditionally established vector control methods such as the use of insecticide, emptying or covering water-filled containers and eliminating mosquito breeding sites have had limited success in curbing the spread of dengue. This calls for experimental and innovative strategies to combat the disease effectively. One promising approach—the Wolbachia-based approach, involves the deployment of Wolbachia-infected mosquitoes into the wild mosquito population. This technique has shown great potential in reducing dengue transmission. While the Wolbachia-based technique has demonstrated highly positive results in mitigating DENV, it is not always successful—Wolbachia strategies may struggle in high temperature settings, because some mosquitoes infected with Wolbachia (such as wMel strain) are unable to transmit Wolbachia maternally to their offspring and establish themselves under high temperatures. Therefore, using thermally tolerant strains may be beneficial in establishing Wolbachia infections in mosquitoes especially in regions with high heat conditions. Although Wolbachia-infected mosquitoes have been rolled out in different countries such as Brazil, Colombia in South America; Indonesia, Taiwan, Viet Nam, Thailand, Malaysia, India in South Asia; Northern Queensland in Australia; and the United States of America, there is arguably no deployment yet made in Africa.
Evaluation of Wolbachia infection in Aedes aegypti suggests low prevalence and highly heterogeneous distribution in Medellín, Colombia
32509rley Calle-Tobón, Raúl Rojo-Ospina, et al., Acta Tropica, 260. 2024-10-08 09:19:14.
Dengue virus, transmitted mainly by Aedes aegypti mosquitoes, is a significant public health challenge in tropical and subtropical countries, with an incidence that is growing at an alarming rate. The release of Wolbachia-carrying mosquitoes has been suggested as a strategy to reduce the incidence of multiple arboviruses. In Medellín, Colombia, large-scale releases of Wolbachia-infected Ae. aegypti mosquitoes were performed between 2017 and 2022 by the World Mosquito Program to facilitate population replacement. In this study, we evaluated the prevalence and distribution of Wolbachia-infected Ae. aegypti two years after completion of these releases. We conducted the sampling across 19 communes in Medellín, using 416 ovitraps to collect Ae. aegypti eggs from epidemiological weeks 26 to 41 in 2023. Upon hatching the collected eggs, we identified and pooled adult female Ae. aegypti for DNA extraction. Subsequently, we conducted PCR assays for the detection of Wolbachia infection in these mosquitoes. We used maximum likelihood estimation (MLE) and Bayesian methods to estimate the prevalence of Wolbachia infection, while using QGIS to analyze spatial distribution of infection in the region. A total of 774 female Ae. aegypti mosquitoes from 182 pools were evaluated. We detected Wolbachia in 33.5 % of pools, with an estimated individual minimum infection rate of 9.5 % and a maximum of 33.2 %. The prevalence varied significantly across communes, with the highest rates observed in the northeastern and southwestern areas. Spatial analysis revealed a highly heterogeneous island-like distribution of Wolbachia across Medellín with a few hotspots. The observed Wolbachia prevalence in this work was lower than previously reported. We suspect a decline in the prevalence of Wolbachia-infected Ae. aegypti mosquitoes in Medellín following the completion of their release.
Excess Lipids Keep Dengue at Bay
31315Shelby Bradford, The Scientist, 2024-09-03 15:36:36.
The Aedes aegypti mosquito can transmit dengue virus; however, infection with endosymbiotic bacteria from the Wolbachia genus reduces viral transmission from these insects. Consequently, Wolbachia-infected mosquitos are one biocontrol agent used in areas with endemic dengue cases. “We are trying to go backwards now, because the intervention works, but we don’t know how,” said Robson Loterio, a microbiologist at the Burnet Institute and author of a paper published in mBio exploring the mechanism of Wolbachia’s antiviral activity. The findings can help researchers prevent viral escape from this biocontrol method. Loterio and his team infected A. aegypti cells with antiviral Wolbachia strains. Using transmission electron microscopy and confocal microscopy, they showed that these bacteria predominantly clustered at the cell’s endoplasmic reticulum (ER). The ER produces molecules used in lipid droplet synthesis. Since both Wolbachia and dengue rely on lipid metabolism, the team investigated the effect of Wolbachia on droplet formation during viral infection by comparing antiviral Wolbachia-infected cells to Wolbachia-free cells. Lipid droplets accumulated in both types of cells, but cells with the bacteria had more lipid accumulation.
Malaria & Dengue; distinguishing mosquito-borne diseases
31178Grace Matheka, HapaKenya, 2024-08-25 20:26:45.
World Mosquito Day is commemorated every year on the 20th of August. The day brings an opportunity to raise awareness on the dangers posed by mosquito-borne diseases like malaria and dengue, and the ongoing efforts to combat them. Both malaria and dengue are transmitted by female mosquitoes and cause severe illness in humans. The two diseases have some similarities, and mosquito species are often confused by patients and medical personnel. Malaria is a leading cause of death in the world, with 200 million cases reported every year worldwide, leading to 600,000 deaths. Most of these deaths happen in Africa, affecting children and pregnant women most. In 2022, WHO reported that Africa was home to 94% of malaria cases at 233 million and 95% at 580 000 of malaria deaths. Children under five accounted for about 78% of all malaria deaths.
A comprehensive review of Wolbachia-mediated mechanisms to control dengue virus transmission in Aedes aegypti through innate immune pathways
31172Iqra Mushtaq, Muhammad Sajjad Sarwar, Iqra Munzoor, Viral Immunology, 15. 2024-08-25 20:04:21.
The Dengue virus (DENV), primarily spread by Aedes aegypti and also by Aedes albopictus in some regions, poses significant global health risks. Alternative techniques are urgently needed because the current control mechanisms are insufficient to reduce the transmission of DENV. Introducing Wolbachia pipientis into Ae. aegypti inhibits DENV transmission, however, the underlying mechanisms are still poorly understood. Innate immune effector upregulation, the regulation of autophagy, and intracellular competition between Wolbachia and DENV for lipids are among the theories for the mechanism of inhibition. Furthermore, mainly three immune pathways Toll, IMD, and JAK/STAT are involved in the host for the suppression of the virus. These pathways are activated by Wolbachia and DENV in the host and are responsible for the upregulation and downregulation of many genes in mosquitoes, which ultimately reduces the titer of the DENV in the host. The functioning of these immune pathways depends upon the Wolbachia, host, and virus interaction. Here, we summarize the current understanding of DENV recognition by the Ae. aegypti’s immune system, aiming to create a comprehensive picture of our knowledge. Additionally, we investigated how Wolbachia regulates the activation of multiple genes associated with immune priming for the reduction of DENV.
Genetically Modified Wolbachia mosquitoes help reduce virus transmission
31461Precision Vaccinations, 2024-08-20 10:33:21.
Every year on World Mosquito Day, diseases spread by mosquitoes, which account for over 17% of all infectious diseases and lead to more than 700,000 deaths annually, are highlighted. Parasites, bacteria, or viruses can cause these diseases, including chikungunya, malaria, dengue, Zika, and yellow fever. While some diseases can be prevented with innovative travel vaccines, some can not. This is why the World Mosquito Program exists today. According to the World Mosquito Program, the Wolbachia method is vital in fighting mosquito-borne diseases and protecting communities worldwide. This program can reduce the number of Aedes aegypti mosquitoes. When male Ae. aegypti mosquitoes with Wolbachia mate with wild female mosquitoes that do not have Wolbachia. The eggs will not hatch. Because the eggs don't hatch, the number of Ae. aegypti mosquitoes decreases. They do this by breeding with wild mosquitoes until, over several generations, they replace the local mosquito population. This means Wolbachia mosquitoes help decrease the risk of dengue, Zika, chikungunya, and yellow fever outbreaks. The World Mosquito Program is currently operating in 13 countries—Australia, Brazil, Colombia, Indonesia, Sri Lanka, Honduras, Laos, Vietnam, Kiribati, Fiji, Vanuatu, New Caledonia, and Mexico—and protects more than 11.4 million people. In the United States, communities in Texas, Florida, and California have released mosquitoes with Wolbachia over the past seven years and a significant decrease in Ae. aegypti mosquitoes have been reported. In 2023, the state of Hawaiʻi also launched a Wolbachia program. Most importantly, the U.S. CDC says no data suggests that Wolbachia bacteria harm people, animals, or the environment. Let's hope locally-acquired chikungunya, dengue, and malaria cases soon become distant memories as disease-carrying mosquitos disappear.
Former minister wants modified mosquitoes to fight dengue spread
30933Otto Carrington, Trinidad and Tobago Guardian, 2024-07-24 15:53:02.
With this country reporting more dengue cases this year than last year and two dengue deaths reported so far, former health minister Dr Fuad Khan is urging the Government to consider genetically modified mosquitoes to help fight the spread of the disease. Khan, who served as Health Minister for one term, proposed in 2011 that genetically modified (GM) male mosquitoes, which have been successfully used in other countries to combat the Aedes aegypti mosquitoes (which cause dengue fever), could be a solution. However, this project never materialised. Speaking on CNC3’s The Morning Brew, Khan again suggested that genetically modified male mosquitoes could be effectively used. “I think that should be looked at again because it has been used successfully in Brazil and Florida.Genetically modified male mosquitoes breeding with female Aedes aegypti is an approach we need to consider. It’s important to find a scientific method to deal with these mosquitoes,” Khan said. He also called for updated legislation to ensure that people are mandated to keep their surroundings clean. He said if they fail to do so, they should be penalised. “It’s crucial to find a scientific way to manage Aedes aegypti mosquitoes. Breeding grounds are straightforward. Everyone should maintain their surroundings, and there should be legislation enforcing this. If the insect vector control team finds that you’re not complying with warnings to clean your yard, you’re endangering public safety,” he stated. Khan added, “Spraying doesn’t work effectively because the breeding ground for mosquitoes is in stagnant water and drains. When you spray, you might kill the mosquitoes flying around temporarily, but you don’t address the larvae in the water. Spraying only kills what’s on the surface.”
Mark–Release–Recapture (MRR) of Sterile Male Aedes albopictus (Skuse) in Sri Lanka: Field Performance of Sterile Males and Estimation of the Wild Mosquito Population Density
30876Hapugoda, Menaka, Nilmini Silva Gunawardena, Tharaka Ranathunge, Jeremy Bouyer, Hamidou Maiga, Kankanige Karunathilake, Gayan Parakrama Withanage, Indika Weerasinghe, Bazoumana B. D. Sow, and Jeevanie Harishchandra, Insects, 15:466. 2024-07-02 13:27:59.
Dengue is an important mosquito-borne disease in Sri Lanka. The Sterile Insect Technique (SIT) is an environment-friendly and novel method that can suppress dengue vector mosquitoes in Sri Lanka. This study aimed to evaluate the field performance of sterile males and the density of wild male Aedes albopictus (Skuse) using a Mark–Release–Recapture (MRR) assay. Laboratory-colonized male pupae were exposed to 50 Gy gamma using a Co60 source. Sterile males (approx. 10,000) marked with fluorescent dust were released weekly for 4 consecutive weeks (January–February 2021) in a geographically isolated 30 ha site in Gampaha. Results show sterile males could disperse up to 543.8 m with a mean distance of 255.1 ± 44.6 m and survive up to 6 days with a mean life expectancy of 3.55 ± 2.32 days. A high field mating competitiveness of sterile males based on a Fried value of 0.47 ± 0.007 and significant induced sterility in the wild eggs in the second generation were found. The mean wild male mosquito population density was 163 males/ha. The data generated will be useful for designing future trials in Sri Lanka and other countries with similar situations.
The race against time to defeat mosquito-borne diseases
30858Michael Peel, Financial Times, 2024-06-28 15:51:06.
Deep in the bowels of Imperial College London’s main campus is a facility known as the insectary. The journey to it, via basement corridors and an entrance that sounds an alarm upon opening, feels like something out of a horror film. Beyond two sets of double doors lies the reason for the security: thousands of the Anopheles mosquito that has long been humanity’s deadliest animal threat. The insects in these temperature-controlled chambers are central to pioneering efforts to use genetic engineering to stop them passing on life-threatening malaria. Federica Bernardini, a research associate, places a hand close to the white mesh sides of a box housing the biting bugs. “I am not going to put it there for long,” Bernardini says, quickly pulling back from the tiny creatures. The Imperial work is part of a global struggle against the intensifying threat of mosquitoes and the destructive pathogens they carry. The first malaria vaccination campaign is being rolled out this year, while researchers are exploring ways to stem disease that are both ingenious and — in the case of genetic engineering — controversial to some. It is part of a wider public health battle against various infectious diseases that have surged in recent years due to environmental change, the Covid-19 pandemic and other factors. The mosquito campaign is a race against the clock. The insects are becoming more resistant to traditional prevention methods, while the climate crisis has opened up new regions where they can thrive.
Simulation-based economic evaluation of the Wolbachia method in Brazil: a cost-effective strategy for dengue control
30927Ivan Ricardo Zimmermann, Ricardo Ribeiro Alves Fernandes, Márcia Gisele Santos da Costa, et al, The Lancet Regional Health - Americas, 35. 2024-06-03 15:30:09.
Dengue virus (DENV) is an arbovirus transmitted by Aedes aegypti mosquitoes, which can cause severe conditions such as hemorrhagic fever and dengue shock syndrome. These conditions are associated with adverse social, clinical, and economic consequences in Brazil. Herein, the Wolbachia mosquito replacement method is a promising dengue control strategy. We estimated the economic impact of implementing the Wolbachia mosquito replacement method in seven Brazilian cities. A mathematical microsimulation model tracked nearly 23 million inhabitants over a 20-year period, considering the transitions between five different health states (susceptible, inapparent, outpatient, hospitalised and death). Direct costs included local dengue control programs, Wolbachia implementation and dengue care. Indirect costs related to death and productivity loss, as well as disability-adjusted life-years (DALY) averted were also considered. Without Wolbachia, the model projected 1,762,688 reported dengue cases over 20 years. Implementing the Wolbachia method would avert at least 1,295,566 dengue cases, resulting in lower costs and greater effectiveness in all simulated cities. On average, for every 1000 inhabitants followed for 20 years, the Wolbachia method yielded a cost difference of USD 538,233.68 (BRL 2,691,168.40) and averted 5.56 DALYs. Net monetary benefits (NMB) were positive in all seven cities, ranging from USD 110.72 (BRL 553.59) to USD 1399.19 (BRL 6995.95) per inhabitant. Alternative scenarios have also shown a favourable return on investment with a positive benefit-cost ratio (BCR).
Scientists use gut bacteria to prevent mosquito-borne diseases
29900CGTN, 2024-05-07 17:04:49.
Chinese scientists have developed a more natural strategy to prevent mosquito-borne diseases by changing insects' gut microbes, which might be used as an alternative to controversial experiments that see genetically-modified mosquitoes released in Florida. Mosquito-borne viruses, such as dengue and Zika, cause several potentially fatal human viral infections. Dengue viruses infect approximately 390 million each year globally. An epidemic survey over the past decade documented frequent dengue outbreaks in Xishuangbanna and Lincang, both in southwest China's Yunnan Province. But few have been reported in neighboring cities of Wenshan and Pu'er. The marked different prevalence stimulated the curiosity of researchers from Tsinghua University and the Yunnan Academy of Animal Science and Veterinary Sciences.
Bacteria found in mosquito guts could help scientists fight dengue, Zika
29548Catherine Offord, Science, 2024-04-25 17:12:41.
A team in China probing the guts of local mosquitoes has found a potential helper in the fight against two human diseases. Researchers identified a new bacterium that disables the viruses responsible for dengue and Zika before they can establish an infection in the insects. Although early stage, the work, reported this week in Science, paves the way for studying the bacterium’s effect on disease transmission in the real world. It wouldn’t be the first time a microbe is used to thwart mosquito-borne diseases. About 15 years ago, researchers discovered that a different bacterium, Wolbachia, reduces the insects’ ability to transmit dengue, among other viruses. Following successful field trials, Wolbachia is now used to help control dengue in more than a dozen countries. But an extra weapon to help control mosquito-borne diseases is welcome—especially as the insects become resistant to current insecticides. The new study is “promising,” says Nsa Dada, a vector biologist at Arizona State University who was not involved in the work. “It’s important that we explore … new tools that can complement existing control measures.” Lacking proven treatments or widely available vaccines, dengue is the most common mosquito-borne viral disease worldwide, infecting some 400 million people each year. Although most cases are mild or asymptomatic, about one in 20 people who get sick develop severe dengue, which can be fatal.
Brazil’s record dengue surge: why a vaccine campaign is unlikely to stop it
29023Mariana Lenharo, Nature, 2024-03-19 12:55:41.
A vaccine shortage and persistent sanitation problems threaten the success of the world’s first public vaccination campaign against dengue virus.
Flight Against Infections: The Role of Genetically Engineered Mosquitoes, with Dr. Stephanie James
28997EeKs on Health, YouTube, 2024-03-11 10:40:20.
In this episode of Causes or Cures, Dr. Eeks chats with Dr. Stephanie James about the potential use of genetically modified mosquitoes (GMMs) to fight diseases that mosquitoes carry and spread, such as Malaria and Dengue Fever. In the podcast, Dr. James provides an overview on GMMs, as well as what something called Gene Drive Modified Mosquitoes (GDMMs) are. She talks about the current state of research, testing, and describes the GeneConvene Global Collaborative "GeneConvene", which was created to advance best practices and informed decision making for developing GMMs and GDMMs. She talks about the potential benefits versus the potential risks, how they are conducting risk assessments, how they plan to test GMMs, the ethical and safety concerns, and how local communities will be included in the decision-making process.
DENV-1 Titer Impacts Viral Blocking in wMel Aedes aegypti with Brazilian Genetic Background
28991Corrêa-Antônio, Jessica, Mariana R. David, Dinair Couto-Lima, Gabriela Azambuja Garcia, Milan S. G. Keirsebelik, Rafael Maciel-de-Freitas, and Márcio Galvão Pavan., Viruses, 16. 2024-03-11 10:08:24.
Several countries have been using Wolbachia deployments to replace highly competent native Aedes aegypti populations with Wolbachia-carrying mosquitoes with lower susceptibility to arboviruses such as dengue, Zika, and chikungunya. In Rio de Janeiro, Wolbachia deployments started in 2015 and still present a moderate introgression with a modest reduction in dengue cases in humans (38%). Here, we evaluated the vector competence of wild-type and wMel-infected Ae. aegypti with a Brazilian genetic background to investigate whether virus leakage could contribute to the observed outcomes in Brazil. We collected the specimens in three areas of Rio de Janeiro with distinct frequencies of mosquitoes with wMel strain and two areas with wild Ae. aegypti. The mosquitoes were orally exposed to two titers of DENV-1 and the saliva of DENV-1-infected Ae. aegypti was microinjected into wMel-free mosquitoes to check their infectivity. When infected with the high DENV-1 titer, the presence of wMel did not avoid viral infection in mosquitoes’ bodies and saliva but DENV-1-infected wMel mosquitoes produced lower viral loads than wMel-free mosquitoes. On the other hand, wMel mosquitoes infected with the low DENV-1 titer were less susceptible to virus infection than wMel-free mosquitoes, although once infected, wMel and wMel-free mosquitoes exhibited similar viral loads in the body and the saliva. Our results showed viral leakage in 60% of the saliva of wMel mosquitoes with Brazilian background; thus, sustained surveillance is imperative to monitor the presence of other circulating DENV-1 strains capable of overcoming the Wolbachia blocking phenotype, enabling timely implementation of action plans.
Effectiveness evaluation of mosquito suppression strategies on dengue transmission under changing temperature and precipitation
28984Kaihui Liu, Shuanghui Fang, Qiong Li, et al., Acta Tropica, 2024-03-05 20:16:41.
Modified mosquitoes may save millions more lives in Latin America
28951Marina E. Franco, Axios, 2024-02-27 18:40:46.
A program that uses genetically engineered mosquitoes in Brazil, Colombia and Mexico to reduce the prevalence of diseases that can be fatal may soon serve millions more people. Why it matters: Outbreaks of dengue, chikungunya, zika and yellow fever —diseases carried by the Aedes aegypti mosquito —have long hit the Americas and other tropical regions hard. Climate change has worsened the spread of these diseases, experts say, as rising temperatures favor the life cycle of the mosquitoes and their proliferation in more areas — including, increasingly, the U.S. These diseases also tend to affect impoverished regions where a lack of health care options mean mosquito bites can become deadly. Diseases such as dengue "feed on poverty and inequity, and they fuel it also," World Health Organization chief Tedros Adhanom Ghebreyesus said last week during an event in Brazil.
South American cities release mosquitoes to stem disease
28913Roberto González, SciDev.Net, 2024-02-20 19:48:12.
When Waldeir Barbosa da Silva explained to his family that he was going to release hundreds of thousands of mosquitoes into the open, infected with a bacterium, they were surprised. In Niterói, southeast Brazil, where da Silva lives, diseases spread by mosquitoes, such as dengue, chikungunya, and Zika, pose a serious public health problem. However, when mosquitoes carry the bacteria Wolbachia, naturally present in many insects, their ability to transmit these viruses decreases.
The epidemiology of imported and locally-acquired dengue in Australia, 2012–2022
28826Asma Sohail, Katherine L Anders, Sarah L McGuinness, Karin Leder, Journal of Travel Medicine, 2024-01-23 17:13:52.
Dengue is the most important arboviral disease globally, and poses ongoing challenges for control including in non-endemic countries with competent mosquito vectors at risk of local transmission through imported cases. We examined recent epidemiological trends in imported and locally-acquired dengue in Australia, where the Wolbachia mosquito population replacement method was implemented throughout dengue-prone areas of northern Queensland between 2011–2019. Dengue is the most important arboviral disease globally, and poses ongoing challenges for control including in non-endemic countries with competent mosquito vectors at risk of local transmission through imported cases. We examined recent epidemiological trends in imported and locally-acquired dengue in Australia, where the Wolbachia mosquito population replacement method was implemented throughout dengue-prone areas of northern Queensland between 2011–2019. Dengue is the most important arboviral disease globally, and poses ongoing challenges for control including in non-endemic countries with competent mosquito vectors at risk of local transmission through imported cases. We examined recent epidemiological trends in imported and locally-acquired dengue in Australia, where the Wolbachia mosquito population replacement method was implemented throughout dengue-prone areas of northern Queensland between 2011–2019.
Wolbachia still works when it is warm
28809McKay, A., Nature Ecology and Evolution, 8. 2024-01-16 13:59:40.
Wolbachia is a maternally inherited endosymbiotic bacterium that can impede the transmission of viruses such as dengue and Zika by some mosquito vectors to humans. Over the past decade, this self-sustaining disease-control method has been rolled out in cities of increasing size; 2023 saw the largest demonstration of efficacy to date, in Medellín, Colombia. However, two key biological mechanisms that enable Wolbachia-carrying mosquitoes to spread in a population — cytoplasmic incompatibility and maternal transmission — have been shown in laboratory conditions to decline under high temperatures. Writing in Nature Climate Change in August 2023, Vásquez and colleagues conducted computational simulations to explore whether near-future warming scenarios are likely to affect the efficacy of Wolbachia-based biocontrol. The models combine empirical estimates of thermal sensitivity for one strain of Wolbachia with projections of future average temperatures and heatwaves for Cairns, Australia and Nha Trang City, Vietnam, two locations where the intervention has been deployed. Estimates of the bacterium’s successful persistence in the mosquito population remain high under tested projections of moderate and severe average warming to 2050. However, the simulations also show reduced efficacy under more variable thermal extremes; these interventions have the potential to fail under extreme warming with long heatwave durations. We selected this paper for our Year in Review collection because it exemplifies how insect thermal biology and global change analysis can offer insights relevant to human health. Testing whether climate change influences Wolbachia-based biocontrol helps to illuminate whether the promising technology is likely to remain feasible in coming years.
Antiviral Wolbachia strains associate with Aedes aegypti endoplasmic reticulum membranes and induce lipid droplet formation to restrict dengue virus replication
28757Robson K. Loterio, Ebony A. Monson, Rachel Templin, Jyotika T. de Bruyne, Heather A. Flores, Jason M. Mackenzie, Georg Ramm, Karla J. Helbig, Cameron P. Simmons, Johanna E. Fraser, Applied and Environmental Microbiology, 2023-12-22 16:16:14.
Wolbachia are a genus of insect endosymbiotic bacteria which includes strains wMel and wAlbB that are being utilized as a biocontrol tool to reduce the incidence of Aedes aegypti-transmitted viral diseases like dengue. However, the precise mechanisms underpinning the antiviral activity of these Wolbachia strains are not well defined. Here, we generated a panel of Ae. aegypti-derived cell lines infected with antiviral strains wMel and wAlbB or the non-antiviral Wolbachia strain wPip to understand host cell morphological changes specifically induced by antiviral strains. Antiviral strains were frequently found to be entirely wrapped by the host endoplasmic reticulum (ER) membrane, while wPip bacteria clustered separately in the host cell cytoplasm. ER-derived lipid droplets (LDs) increased in volume in wMel- and wAlbB-infected cell lines and mosquito tissues compared to cells infected with wPip or Wolbachia-free controls. Inhibition of fatty acid synthase (required for triacylglycerol biosynthesis) reduced LD formation and significantly restored ER-associated dengue virus replication in cells occupied by wMel. Together, this suggests that antiviral Wolbachia strains may specifically alter the lipid composition of the ER to preclude the establishment of dengue virus (DENV) replication complexes. Defining Wolbachia’s antiviral mechanisms will support the application and longevity of this effective biocontrol tool that is already being used at scale.
Utility of surveillance data for planning for dengue elimination in Yogyakarta, Indonesia: a scenario-tree modelling approach
28536Melanie Bannister-Tyrrell, Alison Hillman, Citra Indrian, Riris Andono Ahmad, Adi Utarini, Cameron P Simmons, Katherine L Anders, Evan Sergeant, BMJ Global Health, 8. 2023-11-28 10:54:45.
Field trials and modelling studies suggest that elimination of dengue transmission may be possible through widespread release of Aedes aegypti mosquitoes infected with the insect bacterium Wolbachia pipientis (wMel strain), in conjunction with routine dengue control activities. This study aimed to develop a modelling framework to guide planning for the potential elimination of locally acquired dengue in Yogyakarta, a city of almost 400 000 people in Java, Indonesia. A scenario-tree modelling approach was used to estimate the sensitivity of the dengue surveillance system (including routine hospital-based reporting and primary-care-based enhanced surveillance), and time required to demonstrate elimination of locally acquired dengue in Yogyakarta city, assuming the detected incidence of dengue decreases to zero in the future. Age and gender were included as risk factors for dengue, and detection nodes included the probability of seeking care, probability of sample collection and testing, diagnostic test sensitivity and probability of case notification. Parameter distributions were derived from health system data or estimated by expert opinion. Alternative simulations were defined based on changes to key parameter values, separately and in combination. For the default simulation, median surveillance system sensitivity was 0.131 (95% PI 0.111 to 0.152) per month. Median confidence in dengue elimination reached 80% after a minimum of 13 months of zero detected dengue cases and 90% confidence after 25 months, across different scenarios. The alternative simulations investigated produced relatively small changes in median system sensitivity and time to elimination. This study suggests that with a combination of hospital-based surveillance and enhanced clinic-based surveillance for dengue, an acceptable level of confidence (80% probability) in the elimination of locally acquired dengue can be reached within 2 years. Increasing the surveillance system sensitivity could shorten the time to first ascertainment of elimination of dengue and increase the level of confidence in elimination.
Symbiotic Wolbachia in mosquitoes and its role in reducing the transmission of mosquito-borne diseases: updates and prospects
28311A. Minwuyelet, G. P. Petronio, D. Yewhalaw, A. Sciarretta, I. Magnifico, D. Nicolosi, R. Di Marco and G. Atenafu, Frontiers in Microbiology, 14. 2023-11-08 08:20:47.
Mosquito-borne diseases such as malaria, dengue fever, West Nile virus, chikungunya, Zika fever, and filariasis have the greatest health and economic impact. These mosquito-borne diseases are a major cause of morbidity and mortality in tropical and sub-tropical areas. Due to the lack of effective vector containment strategies, the prevalence and severity of these diseases are increasing in endemic regions. Nowadays, mosquito infection by the endosymbiotic Wolbachia represents a promising new bio-control strategy. Wild-infected mosquitoes had been developing cytoplasmic incompatibility (CI), phenotypic alterations, and nutrition competition with pathogens. These reduce adult vector lifespan, interfere with reproduction, inhibit other pathogen growth in the vector, and increase insecticide susceptibility of the vector. Wild, uninfected mosquitoes can also establish stable infections through trans-infection and have the advantage of adaptability through pathogen defense, thereby selectively infecting uninfected mosquitoes and spreading to the entire population. This review aimed to evaluate the role of the Wolbachia symbiont with the mosquitoes (Aedes, Anopheles, and Culex) in reducing mosquito-borne diseases. Global databases such as PubMed, Web of Sciences, Scopus, and pro-Quest were accessed to search for potentially relevant articles. We used keywords: Wolbachia, Anopheles, Aedes, Culex, and mosquito were used alone or in combination during the literature search. Data were extracted from 56 articles’ texts, figures, and tables of the included article.
Success of Wolbachia-infected mosquitoes in fighting dengue may be underestimated
28353B. Wampler, Notre Dame News, 2023-11-06 11:04:57.
Now, researchers at the University of Notre Dame have conducted an analysis of the World Mosquito Program’s randomized control trial of Wolbachia-infected mosquitoes in Indonesia, looking at how excluding transmission dynamics impacted the original interpretation of the trial’s results. “Randomized controlled trials are the gold standard for evaluating the efficacy of any medical or public health intervention. That is very difficult for vector interventions against dengue because incidence of the disease can be somewhat unpredictable and sporadic, requiring very large-scale trials,” said Alex Perkins, associate professor of biological sciences at Notre Dame and senior author on the study. The study published in BMJ Global Health used mathematical models to analyze dengue virus transmission during the Indonesia trial. They explored three biases, or sources of potential error, that the trial is subject to: human movement, mosquito movement and the combined transmission dynamics between human and mosquito movement.
Dengue rates drop after release of modified mosquitoes in Colombia
28270M. Lenharo, Nature, 2023-10-27 07:52:00.
Three cities in Colombia saw a dramatic fall in the incidence of dengue in the years following the introduction of mosquitoes carrying Wolbachia, a bacterium that prevents the insect from transmitting viruses. In neighbourhoods where the Wolbachia mosquitoes were well established, dengue incidence dropped by 94–97%. The Aedes aegypti mosquitoes were released by the World Mosquito Program (WMP), a non-profit organization that has been conducting similar experiments in Australia, Brazil, Indonesia and Vietnam, among other countries. In Colombia, the modified mosquitoes were released in one of the country’s most populous regions. “That’s the largest continuous releases of Wolbachia [mosquitoes] globally so far, in terms of the population covered and the area,” says Katie Anders, an epidemiologist at the WMP and Monash University in Melbourne, Australia. Anders presented the results on 22 October at the annual meeting of the American Society of Tropical Medicine and Hygiene in Chicago, Illinois.
The double-edged sword effect of expanding Wolbachia deployment in dengue endemic settings
28137M. G. Pavan, G. A. Garcia, M. R. David and R. Maciel-de-Freitas, The Lancet Regional Health - Americas, 27:100610. 2023-10-02 10:16:37.
We can use Brazil as a showcase to foresee and avoid a double-edged sword effect associated with Wolbachia releases. Insecticide resistance of native Ae. aegypti populations is spread worldwide (http://aedes.irmapper.com), and positive results should boost Wolbachia deployment in other dengue endemic settings around the world. Aedes aegypti populations are heterogeneous and nationwide releases of a Wolbachia strain whose genetic backcross belong to a specific locality would produce an unsought homogenization of vector populations. Aedes aegypti homogenisation at large geographic scales could impose additional undesirable consequences in the long-term by promoting genetic hitchhiking of traits such as higher vector competence, lower susceptibility to repellents and insecticides, or more avid host-seeking and biting behaviour. Available data has shown that ensuring adherence to local characteristics, specially a matching genetic between native and released mosquitoes, is critical to enhance the likelihood of achieving a faster introgression in the field, realizing cost and time savings over the globe. Probably there are a myriad of yet undiscovered traits beyond insecticide resistance that may influence vector local adaptation and would affect the success of released strains. Therefore, neglecting the genetic diversity in favour of centralising the rearing of mosquitoes with Wolbachia for nationwide releases could represent a drawback for future releases. Long-term studies regarding the consequences of releasing mosquitoes with homogenous genotypes in diverse ecological and epidemiological scenarios remain a critical research priority, essential for informed decision-making and sustainable management of mosquito-borne diseases.
Unleashing a New Weapon on the Mosquito: A Mosquito
27987S. Nolen and E. Lutz, New York Times, 2023-09-29 08:05:43.
Five decades ago, entomologists confronting the many kinds of suffering that mosquitoes inflict on humans began to consider a new idea: What if, instead of killing the mosquitoes (a losing proposition in most places), you could disarm them? Even if you couldn’t keep them from biting people, what if you could block them from passing on disease? What if, in fact, you could use one infectious microbe to stop another? These scientists began to consider a parasitic bacteria called Wolbachia, which lives quietly in all kinds of insect species. A female mosquito with Wolbachia passes it on in her eggs to all of her offspring, who eventually pass it on to the next generation. But Wolbachia isn’t naturally found in the mosquito species that cause humans the most problems — the Aedes aegypti, the virus carrier, and the Anopheles subspecies, which carry malaria. If it were, it might eventually render those species essentially harmless. So how do you infect a mosquito with Wolbachia?
Quantifying the impact of Wolbachia releases on dengue infection in Townsville, Australia
27831Ogunlade, S. T. Adekunle, A. I. Meehan, M. T. McBryde, E. S., Scientific Reports, 13:14932. 2023-09-11 08:51:39.
From October 2014 to February 2019, local authorities in Townsville, North Queensland, Australia continually introduced Wolbachia-infected mosquitoes to control seasonal outbreaks of dengue infection. In this study, we develop a mathematical modelling framework to estimate the effectiveness of this intervention as well as the relative dengue transmission rates of Wolbachia-infected and wild-type mosquitoes. We find that the transmission rate of Wolbachia-infected mosquitoes is reduced approximately by a factor of 20 relative to the uninfected wild-type population. In addition, the Townsville Wolbachia release program led to a 65% reduction in predicted dengue incidence during the release period and over 95% reduction in the 24 months that followed. Finally, to investigate the potential impact of other Wolbachia release programs, we use our estimates of relative transmissibility to calculate the relationship between the reproductive number of dengue and the proportion of Wolbachia-infected mosquitoes in the vector population.
Buzzing breakthrough: genetic engineering gives mosquito control an upgrade
27841Sivasubbu, Sridhar Scaria, Vinod, The Hindu, 2023-09-10 09:28:26.
Throughout human history, mosquitoes have constantly buzzed in the background of human existence, irritating us with their incessant bites and occasionally wreaking havoc by transmitting deadly diseases. The earliest known mosquitoes from the fossil record date back at least 70 million years, and evidence of mosquito-borne diseases like malaria dates back to Egyptian mummies from 2000 BC. Apart from malaria, which claims the lives of over half a million people every year and infects close to 250 million, mosquitoes serve as vectors for various other diseases. These include dengue, Zika, lymphatic filariasis, and yellow fever. Understandably, our relationship with these tiny, blood-sucking insects has been far from cordial.
Jamestown Canyon virus is transmissible by Aedes aegypti and is only moderately blocked by Wolbachia co-infection
27755M. J. Lau, H. L. C. Dutra, M. J. Jones, B. P. McNulty, A. M. Diaz, F. Ware-Gilmore and E. A. McGraw, PLOS Neglected Tropical Diseases, 17. 2023-09-05 07:50:16.
Jamestown Canyon virus (JCV), a negative-sense arbovirus, is increasingly common in the upper Midwest of the USA. Transmitted by a range of mosquito genera, JCV's primary amplifying host is white-tailed deer. Aedes aegypti is responsible for transmitting various positive-sense viruses globally including dengue (DENV), Zika, chikungunya, and Yellow Fever. Ae. aegypti's distribution, once confined to the tropics, is expanding, in part due to climate change. Wolbachia, an insect endosymbiont, limits the replication of co-infecting viruses inside insects. The release and spread of the symbiont into Ae. aegypti populations have been effective in reducing transmission of DENV to humans, although the mechanism of Wolbachia-mediated viral blocking is still poorly understood. Here we explored JCV infection potential in Ae. aegypti, the nature of the vector's immune response, and interactions with Wolbachia infection. We show that Ae. aegypti is highly competent for JCV, which grows to high loads and rapidly reaches the saliva after an infectious blood meal. The mosquito immune system responds with strong induction of RNAi and JAK/STAT. Neither the direct effect of viral infection nor the energetic investment in immunity appears to affect mosquito longevity. Wolbachia infection blocked JCV only in the early stages of infection. Wolbachia-induced immunity was small compared to that of JCV, suggesting innate immune priming does not likely explain blocking. We propose two models to explain why Wolbachia's blocking of negative-sense viruses like JCV may be less than that of positive-sense viruses, relating to the slowdown of host protein synthesis and the triggering of interferon-like factors like Vago. In conclusion, we highlight the risk for increased human disease with the predicted future overlap of Ae. aegypti and JCV ranges. We suggest that with moderate Wolbachia-mediated blocking and distinct biology, negative-sense viruses represent a fruitful comparator model to other viruses for understanding blocking mechanisms in mosquitoes.
Does ignoring transmission dynamics lead to underestimation of the impact of interventions against mosquito-borne disease?
27695S. Cavany, J. Huber, H. , A. Wieler, Q. M. Tran, M. Alkuzweny, M. Elliott, G. España, S. Moore, M. and T. A. Perkins, BMJ Global Health, 8:e012169. 2023-08-31 09:07:49.
New vector-control technologies to fight mosquito-borne diseases are urgently needed, the adoption of which depends on efficacy estimates from large-scale cluster-randomised trials (CRTs). The release of Wolbachia-infected mosquitoes is one promising strategy to curb dengue virus (DENV) transmission, and a recent CRT reported impressive reductions in dengue incidence following the release of these mosquitoes. Such trials can be affected by multiple sources of bias, however. We used mathematical models of DENV transmission during a CRT of Wolbachia-infected mosquitoes to explore three such biases: human movement, mosquito movement and coupled transmission dynamics between trial arms. We show that failure to account for each of these biases would lead to underestimated efficacy, and that the majority of this underestimation is due to a heretofore unrecognised bias caused by transmission coupling. Taken together, our findings suggest that Wolbachia-infected mosquitoes could be even more promising than the recent CRT suggested. By emphasising the importance of accounting for transmission coupling between arms, which requires a mathematical model, we highlight the key role that models can play in interpreting and extrapolating the results from trials of vector control interventions.Data are available in a public, open access repository. All code and other files to reproduce our results is available at: https://github.com/scavany/awed_trial_modeling/
Wolbachia wMel strain-mediated effects on dengue virus vertical transmission from Aedes aegypti to their offspring
27693K. Duong Thi Hue, D. da Silva Goncalves, V. Tran Thuy, L. Thi Vo, D. Le Thi, N. Vu Tuyet, G. Nguyen Thi, T. Huynh Thi Xuan, N. Nguyen Minh, P. Nguyen Thanh, S. Yacoub and C. P. Simmons, Parasites and Vectors, 16:308. 2023-08-31 08:53:50.
Background Dengue virus serotypes (DENV-1 to -4) can be transmitted vertically in Aedes aegpti mosquitoes. Whether infection with the wMel strain of the endosymbiont Wolbachia can reduce the incidence of vertical transmission of DENV from infected females to their offspring is not well understood. Methods A laboratory colony of Vietnamese Ae. aegypti, both with and without wMel infection, were infected with DENV-1 by intrathoracic injection (IT) to estimate the rate of vertical transmission (VT) of the virus. VT in the DENV-infected mosquitoes was calculated via the infection rate estimation from mosquito pool data using maximum likelihood estimation (MLE). Results In 6047 F1 Vietnamese wild-type Ae. aegypti, the MLE of DENV-1 infection was 1.49 per 1000 mosquitoes (95% confidence interval [CI] 0.73–2.74). In 5500 wMel-infected Ae. aegypti, the MLE infection rate was 0 (95% CI 0–0.69). The VT rates between mosquito lines showed a statistically significant difference. Conclusions The results reinforce the view that VT is a rare event in wild-type mosquitoes and that infection with wMel is effective in reducing VT.
The impact of predators of mosquito larvae on Wolbachia spreading dynamics
27651Z. Zhu, Y. Hui and L. Hu, Journal of Biological Dynamics, 17:2249024. 2023-08-21 07:05:13.
Dengue fever creates more than 390 million cases worldwide yearly. The most effective way to deal with this mosquito-borne disease is to control the vectors. In this work we consider two weapons, the endosymbiotic bacteria Wolbachia and predators of mosquito larvae, for combating the disease. As Wolbachia-infected mosquitoes are less able to transmit dengue virus, releasing infected mosquitoes to invade wild mosquito populations helps to reduce dengue transmission. Besides this measure, the introduction of predators of mosquito larvae can control mosquito population. To evaluate the impact of the predators on Wolbachia spreading dynamics, we develop a stage-structured five-dimensional model, which links the predator-prey dynamics with the Wolbachia spreading. By comparatively analysing the dynamics of the models without and with predators, we observe that the introduction of the predators augments the number of coexistence equilibria and impedes Wolbachia spreading. Some numerical simulations are presented to support and expand our theoretical results.
Can Gene-Drives Combat Vector-Borne Diseases?
27636Anonymous, tomorrow.bio, 2023-08-18 07:40:46.
Scientists, technophiles, and the medical community are abuzz with a topic that sounds like science fiction: gene-drives. Given the growing fear of vector-borne diseases, wouldn’t it be marvelous if we could meddle with genetics to drive vectors like mosquitoes to extinction? Sounds too good to be true? Let’s dive into it! Understanding Gene-Drives To comprehend how gene-drives might revolutionize disease control, we first need to understand what they are. Think of gene-drives as inherently selfish genes that ensure their own propagation throughout a population, bypassing traditional inheritance rules of mother nature. Quite enjoyably sneaky, isn't it?
British super mosquitoes being deployed to wipe out malaria from the planet
27622J. Lawton, Daily Star, 2023-08-15 10:00:16.
The Brit-made mosquitoes are all male and carry a special gene to prevent female offspring from surviving into adulthood.Only females bite and spread malaria. Released into the wild Oxitec’s genetically-modified males mate with wild females. All the female offspring then die. Males - which do not bite or spread the disease - survive and go on to mate with other wild females `dramatically’ reducing the world’s mosquito population and the "spread of malaria". according to Gates. Tests have shown the super mozzies pose no risk to the environment or humans. More than one billion have so far been released worldwide with "no negative impacts", Bill wrote in an online blog. In Brazil the Brit buzzers are helping eliminate dengue fever - another mosquito-transmitted disease which kills up to 40,000-a-year. They will be introduced to Djibouti in east Africa next year to stop a rise in the number of malaria cases from 27 in 2012 to 73,000 in 2020.
EPA Authorized Release Of 2 Billion More GMO Mosquitos
27606T. Mateescu, Health Thoroughfare, 2023-08-09 07:34:11.
A biotechnology company called Oxitec has produced genetically modified mosquitoes named GE mosquitoes. These mosquitoes are being released in the U.S. for a real-world experiment. Oxitec is using Aedes aegypti (A. aegypti) mosquitoes for this experiment. This species is known to carry diseases like yellow fever, dengue fever, chikungunya, Zika, West Nile, and Mayaro, a dengue-like disease. Oxitec genetically engineered the males of this species to carry a “genetic kill switch.” When they mate with wild female mosquitoes, their offspring inherit the lethal gene, and they cannot survive or reproduce in the wild. Oxitec is marketing these insects as “Oxitec Friendly” mosquitoes in the U.S.
Baker: New tools can change mosquitoes’ DNA, but should it be done?
27597K. Baker, Fremont News Messenger, 2023-08-09 06:54:53.
Suppose Sauron — or perhaps Gandalf — were to offer you a magical golden ring with the power to rid the world of mosquitoes once and for all. And with their demise, to save countless human lives from the many diseases for which mosquitoes are the sole or primary vectors: Malaria, dengue, West Nile virus, chikungunya, yellow fever, filariasis, tularemia, encephalitis, Zika fever, Keystone Virus, Rift Valley Fever…And not just mosquitoes. From within the folds of his cloak the wizard draws out an array of equally luminous rings with the power to cure genetic disorders like cystic fibrosis, hemophilia, and Down’s syndrome, to rid cities of mice and rats, and free the world’s farms of weeds and insect pests without the use of pesticides. Would you take them? Those rings exist and are now being refined and tested in the Elvin forges of academic, commercial, and government research facilities around the world. They go by various names, but collectively may be referred to as CRISPR-Cas Genome Editing Systems.
Scientists are releasing disease-resistant mosquitoes. But heat waves could kill them.
27586C. Harvey, Politico, 2023-08-04 08:21:30.
A new study, published Thursday in the journal Nature Climate Change, suggests that the disease-quashing bugs will likely survive for at least the next couple of decades. Their fate is less certain further into the future. The study focuses on a special insect-borne bacterium called Wolbachia, which has natural virus-blocking properties and is carried in different insect populations, including some mosquito species. It’s not typically found in Aedes aegypti, or the “yellow fever mosquito,” one of the most significant disease-carrying species on the planet. But scientists have figured out ways to introduce the bacteria into Aedes aegypti populations — and potentially slow the transmission of diseases including yellow fever and dengue fever and the Zika and chikungunya viruses.
Suppression Trial through an Integrated Vector Management of Aedes albopictus (Skuse) Based on the Sterile Insect Technique in a Non-Isolated Area in Spain
27563C. Tur, D. Almenar, M. Zacarés, S. Benlloch-Navarro, I. Pla and V. Dalmau, Insects, 14. 2023-08-03 07:16:56.
In recent years, Aedes albopictus (Skuse, 1984) has expanded its distribution globally due to its high ecological plasticity. This expansion has increased the population’s susceptibility to contracting diseases such as dengue, Zika, and chikungunya, among others, which are transmitted by this mosquito species. In the absence of effective control methods, the application of the sterile insect technique (SIT) is proposed as part of an integrated vector management (IVM) program. From 2007 to 2020, this strategy has been tested in a non-isolated mosquito population urban area of 45 ha, representative of the municipalities of the Valencian region (Spain). The population levels of adult females and eggs collected in the traps have been reduced by 70–80% compared to the control area, demonstrating its efficacy in reducing mosquito populations. This work analyzes the impact of the migration of the wild mosquito population from the peri-urban area to the urban core.
wMel replacement of dengue-competent mosquitoes is robust to near-term change
27584V. N. Vásquez, L. M. Kueppers, G. Rašić and J. M. Marshall, Nature Climate Change, 13:848-855. 2023-08-01 08:16:33.
Rising temperatures are impacting the range and prevalence of mosquito-borne diseases. A promising biocontrol technology replaces wild mosquitoes with those carrying the virus-blocking Wolbachia bacterium. Because the most widely used strain, wMel, is adversely affected by heat stress, we examined how global warming may influence wMel-based replacement. We simulated interventions in two locations with successful field trials using Coupled Model Intercomparison Project Phase 5 climate projections and historical temperature records, integrating empirical data on wMel’s thermal sensitivity into a model of Aedes aegypti population dynamics to evaluate introgression and persistence over one year. We show that in Cairns, Australia, climatic futures necessitate operational adaptations for heatwaves exceeding two weeks. In Nha Trang, Vietnam, projected heatwaves of three weeks and longer eliminate wMel under the most stringent assumptions of that symbiont’s thermal limits. We conclude that this technology is generally robust to near-term (2030s) climate change. Accelerated warming may challenge this in the 2050s and beyond.
Susceptibility of Wolbachia mosquito control to temperature shifts
27579E. P. Caragata, Nature Climate Change, 13:767-768. 2023-08-01 08:10:19.
Vásquez and colleagues consider the potential impacts of increasing and variable temperatures on Wolbachia-based population-replacement interventions. Previous laboratory experiments have highlighted the temperature-sensitive nature of Wolbachia, with high average daily temperatures and prolonged heatwaves potentially decreasing Wolbachia titre, leading to weakening or loss of maternal transmission, cytoplasmic incompatibility and virus blocking . In nature, this could potentially hinder or thwart interventions. Vásquez and colleagues use Coupled Model Intercomparison Project Phase 5 climate projections to model the efficacy of population-replacement interventions utilizing the wMel Wolbachia strain in Ae. aegypti in Cairns, Australia, and in Nha Trang, Vietnam, two current intervention sites. Their mechanistic models compare population-replacement efficiency under current temperature regimes, and those projected for the 2030s (2024–2039) and 2050s (2044–2059). These models also incorporate loss of wMel infection at an average daily temperature threshold of 35 °C (based on laboratory data ), or more stringently, at 33 °C or 31.5 °C.
Unleashing the swarm: Battling the global mosquito menace and defending public health
26467J. Entine and S. Moxon, Genetic Literacy Project, 2023-07-05 07:47:22.
There is one solution embraced by global health experts that should be pursued aggressively, if with some caution. Scientists in real-world trials have altered the genomes of entire animal populations, including mosquitoes, to thwart the vectoring of diseases and control pests — an innovation called gene drives. Emerging gene drive technologies offer enormous potential and have already shown their value in test projects in many parts of the world. More recently, the application of CRISPR/Cas9 tools has dramatically accelerated their effectiveness. But implementation on a wider scale is progressing at a snail’s pace. Why? For the most part, it is restrained by controversy, misunderstanding and the political opposition of activist environmental groups in Europe and North America.
Wolbachia -mediated resistance to Zika virus infection in Aedes aegypti is dominated by diverse transcriptional regulation and weak evolutionary pressures
26604E. C. Boehm, A. S. Jaeger, H. J. Ries, D. Castañeda, A. M. Weiler, C. C. Valencia, J. Weger-Lucarelli, G. D. Ebel, S. L. O'Connor, T. C. Friedrich, M. Zamanian and M. T. Aliota, bioRxiv, 2023-06-26 13:09:35.
A promising candidate for arbovirus control and prevention relies on replacing arbovirus-susceptible Aedes aegypti populations with mosquitoes that have been colonized by the intracellular bacterium Wolbachia and thus have a reduced capacity to transmit arboviruses. This reduced capacity to transmit arboviruses is mediated through a phenomenon referred to as pathogen blocking. Pathogen blocking has primarily been proposed as a tool to control dengue virus (DENV) transmission, however it works against a range of viruses, including Zika virus (ZIKV). Despite years of research, the molecular mechanisms underlying pathogen blocking still need to be better understood. Here, we used RNA-seq to characterize mosquito gene transcription dynamics in Ae. aegypti infected with the w Mel strain of Wolbachia that are being released by the World Mosquito Program in Medellín, Colombia. Comparative analyses using ZIKV-infected, uninfected tissues, and mosquitoes without Wolbachia revealed that the influence of w Mel on mosquito gene transcription is multifactorial. Importantly, because Wolbachia limits, but does not completely prevent, replication of ZIKV and other viruses in coinfected mosquitoes, there is a possibility that these viruses could evolve resistance to pathogen blocking. Therefore, to understand the influence of Wolbachia on within-host ZIKV evolution, we characterized the genetic diversity of molecularly barcoded ZIKV virus populations replicating in Wolbachia -infected mosquitoes and found that within-host ZIKV evolution was subject to weak purifying selection and, unexpectedly, loose anatomical bottlenecks in the presence and absence of Wolbachia . Together, these findings suggest that there is no clear transcriptional profile associated with Wolbachia -mediated ZIKV restriction, and that there is no evidence for ZIKV escape from this restriction in our system. AUTHOR SUMMARY: When Wolbachia bacteria infect Aedes aegypti mosquitoes, they dramatically reduce the mosquitoes' susceptibility to infection with a range of arthropod-borne viruses, including Zika virus (ZIKV). Although this pathogen-blocking effect has been widely recognized, its mechanisms remain unclear. Furthermore, because Wolbachia limits, but does not completely prevent, replication of ZIKV and other viruses in coinfected mosquitoes, there is a possibility that these viruses could evolve resistance to Wolbachia -mediated blocking. Here, we use host transcriptomics and viral genome sequencing to examine the mechanisms of ZIKV pathogen blocking by Wolbachia and viral evolutionary dynamics in Ae. aegypti mosquitoes. We find complex transcriptome patterns that do not suggest a single clear mechanism for pathogen blocking. We also find no evidence that Wolbachia exerts detectable selective pressures on ZIKV in coinfected mosquitoes. Together our data suggest that it may be difficult for ZIKV to evolve Wolbachia resistance, perhaps due to the complexity of the pathogen blockade mechanism.
MGSurvE: A framework to optimize trap placement for genetic surveillance of mosquito population
26616C. H. Sánchez, D. L. Smith and J. M. Marshall, bioRxiv, 2023-06-23 13:35:51.
Genetic surveillance of mosquito populations is becoming increasingly relevant as genetics-based mosquito control strategies advance from laboratory to field testing. Especially applicable are mosquito gene drive projects, the potential scale of which leads monitoring to be a significant cost driver. For these projects, monitoring will be required to detect unintended spread of gene drive mosquitoes beyond field sites, and the emergence of alternative alleles, such as drive-resistant alleles or non-functional effector genes, within intervention sites. This entails the need to distribute mosquito traps efficiently such that an allele of interest is detected as quickly as possible - ideally when remediation is still viable. Additionally, insecticide-based tools such as bednets are compromised by insecticide-resistance alleles for which there is also a need to detect as quickly as possible. To this end, we present MGSurvE (Mosquito Gene SurveillancE): a computational framework that optimizes trap placement for genetic surveillance of mosquito populations such that the time to detection of an allele of interest is minimized. A key strength of MGSurvE is that it allows important biological features of mosquitoes and the landscapes they inhabit to be accounted for, namely: i) resources required by mosquitoes (e.g., food sources and aquatic breeding sites) can be explicitly distributed through a landscape, ii) movement of mosquitoes may depend on their sex, the current state of their gonotrophic cycle (if female) and resource attractiveness, and iii) traps may differ in their attractiveness profile. Example MGSurvE analyses are presented to demonstrate optimal trap placement for: i) an Aedes aegypti population in a suburban landscape in Queensland, Australia, and ii)an Anopheles gambiae population on the island of São Tomé, São Tomé and Príncipe. Further documentation and use examples are provided in project's documentation. MGSurvE is freely available as an open-source Python package on pypi ( https://pypi.org/project/MGSurvE/ ). It is intended as a resource for both field and computational researchers interested in mosquito gene surveillance. AUTHOR SUMMARY: Mosquito-borne diseases such as malaria and dengue fever continue to pose a major health burden throughout much of the world. The impact of currently-available tools, such as insecticides and antimalarial drugs, is stagnating, and gene drive-modified mosquitoes are considered a novel tool that could contribute to continuing reductions in disease transmission. Gene drive approaches are unique in the field of vector control in that they involve transgenes that could potentially spread on a wide scale, and consequently, surveillance is expected to be a major cost driver for the technology. This is needed to monitor for unintended spread of intact drive alleles, and the emergence of alternative alleles such as homing-resistance alleles and non-functional effector genes. Additionally, surveillance of insecticide-resistance alleles is of interest to support the impact of insecticide-based tools such as bednets. Here, we present MGSurvE, a computational framework that optimizes trap placement for genetic surveillance of mosquito populations in order to minimize the time to detection for an allele of interest. MGSurvE has been tailored to various features of mosquito ecology, and is intended as a resource for researchers to optimize the efficiency of limited surveillance resources.
An economic evaluation of Wolbachia deployments for dengue control in Vietnam
25418H. C. Turner, D. L. Quyen, R. Dias, P. T. Huong, C. P. Simmons and K. L. Anders, PLOS Neglected Tropical Diseases, 17:e0011356. 2023-05-30 07:56:11.
INTRODUCTION: Dengue is a major public health challenge and a growing problem due to climate change. The release of Aedes aegypti mosquitoes infected with the intracellular bacterium Wolbachia is a novel form of vector control against dengue. However, there remains a need to evaluate the benefits of such an intervention at a large scale. In this paper, we evaluate the potential economic impact and cost-effectiveness of scaled Wolbachia deployments as a form of dengue control in Vietnam-targeted at the highest burden urban areas. METHODS: Ten settings within Vietnam were identified as priority locations for potential future Wolbachia deployments (using a population replacement strategy). The effectiveness of Wolbachia deployments in reducing the incidence of symptomatic dengue cases was assumed to be 75%. We assumed that the intervention would maintain this effectiveness for at least 20 years (but tested this assumption in the sensitivity analysis). A cost-utility analysis and cost-benefit analysis were conducted. RESULTS: From the health sector perspective, the Wolbachia intervention was projected to cost US$420 per disability-adjusted life year (DALY) averted. From the societal perspective, the overall cost-effectiveness ratio was negative, i.e. the economic benefits outweighed the costs. These results are contingent on the long-term effectiveness of Wolbachia releases being sustained for 20 years. However, the intervention was still classed as cost-effective across the majority of the settings when assuming only 10 years of benefits. CONCLUSION: Overall, we found that targeting high burden cities with Wolbachia deployments would be a cost-effective intervention in Vietnam and generate notable broader benefits besides health gains.
Holobiont perspectives on tripartite interactions among microbiota, mosquitoes, and pathogens
25208R. Zheng, Q. Wang, R. Wu, P. N. Paradkar, A. A. Hoffmann and G. H. Wang, ISME, 2023-05-25 13:32:28.
Mosquito-borne diseases like dengue and malaria cause a significant global health burden. Unfortunately, current insecticides and environmental control strategies aimed at the vectors of these diseases are only moderately effective in decreasing disease burden. Understanding and manipulating the interaction between the mosquito holobiont (i.e., mosquitoes and their resident microbiota) and the pathogens transmitted by these mosquitoes to humans and animals could help in developing new disease control strategies. Different microorganisms found in the mosquito's microbiota affect traits related to mosquito survival, development, and reproduction. Here, we review the physiological effects of essential microbes on their mosquito hosts; the interactions between the mosquito holobiont and mosquito-borne pathogen (MBP) infections, including microbiota-induced host immune activation and Wolbachia-mediated pathogen blocking (PB); and the effects of environmental factors and host regulation on the composition of the microbiota. Finally, we briefly overview future directions in holobiont studies, and how these may lead to new effective control strategies against mosquitoes and their transmitted diseases.
Targeting Sex Determination to Suppress Mosquito Populations
24988L. Ming, P. K. Nikolay, S. Ruichen, Y. Ting, D. B. Elena, J. B. Daniel, A. Igor, M. S. C. Hector, Z. Yinpeng, A. D. Nicolas, M. L. YuMin, P. S. Matthew, M. Craig, M. M. John and S. A. Omar, bioRxiv, 2023.04.18.537404. 2023-04-20 14:45:03.
Each year, hundreds of millions of people are infected with arboviruses such as dengue, yellow fever, chikungunya, and Zika, which are all primarily spread by the notorious mosquito Aedes aegypti. Traditional control measures have proven insufficient, necessitating innovations. In response, here we generate a next generation CRISPR-based precision-guided sterile insect technique (pgSIT) for Aedes aegypti that disrupts genes essential for sex determination and fertility, producing predominantly sterile males that can be deployed at any life stage. Using mathematical models and empirical testing, we demonstrate that released pgSIT males can effectively compete with, suppress, and eliminate caged mosquito populations. This versatile species-specific platform has the potential for field deployment to control wild populations, safely curtailing disease transmission.Competing Interest StatementO.S.A. is a founder of Agragene, Inc. with equity interest. O.S.A., M.L., and N.P.K are founders of Synvect with equity interest. The terms of this arrangement have been reviewed and approved by the University of California, San Diego in accordance with its conflict of interest policies. All remaining authors declare no competing interests.
Massive mosquito factory in Brazil aims to halt dengue
24984M. Lenharo, Nature, 2023-04-14 09:48:56.
The non-profit World Mosquito Program (WMP) has announced that it will release modified mosquitoes in many of Brazil’s urban areas over the next 10 years, with the aim of protecting up to 70 million people from diseases such as dengue. Researchers have tested the release of this type of mosquito — which carries a Wolbachia bacterium that stops the insect from transmitting viruses — in select cities in countries such as Australia, Brazil, Colombia, Indonesia and Vietnam. But this will be the first time that the technology is dispersed nationwide. A mosquito factory will be built in a location yet to be determined in Brazil to supply the WMP’s ambitious initiative, in partnership with the Oswaldo Cruz Foundation (Fiocruz), a Brazilian public science institution in Rio de Janeiro. The facility should begin operating in 2024 and will produce up to five billion mosquitoes per year. “This will be the biggest facility in the world” to produce Wolbachia-infected mosquitoes, says Scott O’Neill, a microbiologist at Monash University in Melbourne, Australia, and head of the WMP. “And it will allow us in a short period of time to cover more people than in any other country.” Brazil has one of the highest rates of dengue infection in the world, reporting more than two million cases in 2022.Despite the positive results from past mosquito releases, researchers expect that it will be challenging to operate the technology at such a massive scale.
Dengue Exposure and Wolbachia wMel Strain Affects the Fertility of Quiescent Eggs of Aedes aegypti
25102M. T. Petersen, D. Couto-Lima, G. A. Garcia, M. G. Pavan, M. R. David and R. Maciel-de-Freitas, Viruses, 15. 2023-04-12 10:20:54.
(1) Background: The deployment of the bacterium Wolbachia to reduce arbovirus transmission is ongoing in several countries worldwide. When Wolbachia-carrying Aedes aegypti are released and established in the field, females may feed on dengue-infected hosts. The effects of simultaneous exposure on life-history traits of Ae. aegypti to Wolbachia wMel strain and dengue-1 virus DENV-1 remain unclear. (2) Methods: We monitored 4 groups (mosquitoes with either DENV-1 or Wolbachia, coinfected with DENV-1 and Wolbachia, as well as negative controls) to estimate Ae. aegypti survival, oviposition success, fecundity, collapsing and fertility of quiescent eggs for 12 weeks. (3) Results: Neither DENV-1 nor Wolbachia had a significant impact on mosquito survival nor on mosquito fecundity, although the last parameter showed a tendency to decrease with ageing. There was a significant decrease in oviposition success in individuals carrying Wolbachia. Wolbachia infection and storage time significantly increased egg collapse parameter on the egg viability assay, while DENV-1 had a slight protective effect on the first four weeks of storage. (4) Conclusions: Despite limitations, our results contribute to better understanding of the tripartite interaction of virus, bacteria and mosquito that may take place in field conditions and aid in guaranteeing the Wolbachia strategy success.
Spatial Distribution and Long-Term Persistence of Wolbachia-Infected Aedes aegypti in the Mentari Court, Malaysia
25100Y. L. Cheong, W. A. Nazni, H. L. Lee, A. NoorAfizah, I. C. MohdKhairuddin, G. M. R. Kamarul, N. M. N. Nizam, M. A. K. Arif, Z. M. NurZatilAqmar, S. M. Irwan, K. Khadijah, Y. M. Paid, O. Topek, A. H. Hasnor, R. AbuBakar, B. Singh Gill, K. Fadzilah, A. Tahi, Insects, 14. 2023-04-11 10:16:44.
Dengue is endemic in Malaysia, and vector control strategies are vital to reduce dengue transmission. The Wolbachia strain wAlbB carried by both sexes of Ae. aegypti was released in Mentari Court, a high-rise residential site, in October 2017 and stopped after 20 weeks. Wolbachia frequencies are still being monitored at multiple traps across this site, providing an opportunity to examine the spatiotemporal distribution of Wolbachia and mosquito density with respect to year, residential block, and floor, using spatial interpolation in ArcGIS, GLMs, and contingency analyses. In just 12 weeks, Wolbachia-infected mosquitoes were established right across the Mentari Court site with an overall infection frequency of >90%. To date, the Wolbachia frequency of Ae. aegypti has remained high in all areas across the site despite releases finishing four years ago. Nevertheless, the Wolbachia invaded more rapidly in some residential blocks than others, and also showed a relatively higher frequency on the eighth floor. The Ae. aegypti index tended to differ somewhat between residential blocks, whilst the Ae. albopictus index was relatively higher at the top and bottom floors of buildings. In Mentari Court, only a short release period was required to infiltrate Wolbachia completely and stably into the natural population. The results inform future releases in comparable sites in a dengue control programme.
Galapagos to receive male mosquitoes for vector control in Ecuador
24835A. R. Martin, Prensa Latina, 2023-03-07 08:39:27.
The Galapagos Islands will receive 100,000 sterile male mosquitoes as part of a new vector control strategy in Ecuador, the Center for Research in Infectious and Vector Diseases (CIREV) announced. Reducing the Aedes aegypti in Ecuador is in charge of the National Institute for Public Health Research (INSPI), and will start off the experimental phase coming Friday, March 10. The research, which started in 2017, is co-financed by the Technical Cooperation Program of the International Atomic Energy Agency
Analysing inhibition of dengue virus in Wolbachia-infected mosquito cells following the removal of Wolbachia
24822M. Hussain, K. Etebari and S. Asgari, Virology, 581:48-55. 2023-03-03 10:30:05.
Wolbachia pipientis is known to block replication of positive sense RNA viruses. Previously, we created an Aedes aegypti Aag2 cell line (Aag2.wAlbB) transinfected with the wAlbB strain of Wolbachia and a matching tetracycline-cured Aag2.tet cell line. While dengue virus (DENV) was blocked in Aag2.wAlbB cells, we found significant inhibition of DENV in Aag2.tet cells. RNA-Seq analysis of the cells confirmed removal of Wolbachia and lack of expression of Wolbachia genes that could have been due to lateral gene transfer in Aag2.tet cells. However, we noticed a substantial increase in the abundance of phasi charoen-like virus (PCLV) in Aag2.tet cells. When RNAi was used to reduce the PCLV levels, DENV replication was significantly increased. Further, we found significant changes in the expression of antiviral and proviral genes in Aag2.tet cells. Overall, the results reveal an antagonistic interaction between DENV and PCLV and how PCLV-induced changes could contribute to DENV inhibition.
Genome evolution of dengue virus serotype 1 under selection by Wolbachia pipientis in Aedes aegypti mosquitoes
27978D. Thi Hue Kien, K. Edenborough, D. da Silva Goncalves, T. Thuy Vi, E. Casagrande, H. Thi Le Duyen, V. Thi Long, L. Thi Dui, V. Thi Tuyet Nhu, N. Thi Giang, H. Thi Xuan Trang, E. Lee, I. a. Donovan-Banfield, H. Thi Thuy Van, N. Minh Nguyet, N. Thanh Phong, Virus Evolution, 9:vead016. 2023-03-03 07:47:19.
The introgression of antiviral strains of Wolbachia into Aedes aegypti mosquito populations is a public health intervention for the control of dengue. Plausibly, dengue virus (DENV) could evolve to bypass the antiviral effects of Wolbachia and undermine this approach. Here, we established a serial-passage system to investigate the evolution of DENV in Ae. aegypti mosquitoes infected with the wMel strain of Wolbachia. Using this system, we report on virus genetic outcomes after twenty passages of serotype 1 of DENV (DENV-1). An amino acid substitution, E203K, in the DENV-1 envelope protein was more frequently detected in the consensus sequence of virus populations passaged in wMel-infected Ae. aegypti than wild-type counterparts. Positive selection at residue 203 was reproducible; it occurred in passaged virus populations from independent DENV-1-infected patients and also in a second, independent experimental system. In wild-type mosquitoes and human cells, the 203K variant was rapidly replaced by the progenitor sequence. These findings provide proof of concept that wMel-associated selection of virus populations can occur in experimental conditions. Field-based studies are needed to explore whether wMel imparts selective pressure on DENV evolution in locations where wMel is established.
Engineered Antiviral Sensor Targets Infected Mosquitoes
24617E. Dalla Benetta, A. J. Lopez-Denman, H.-H. Li, R. A. Masri, D. J. Brogan, M. Bui, T. Yang, M. Li, M. Dunn, M. J. Klein, S. Jackson, K. Catalan, K. R. Blasdell, P. Tng, I. Antoshechkin, L. S. Alphey, P. N. Paradkar and O. Akbari, bioRxiv, 2023.01.27.525922. 2023-01-27 09:22:47.
Escalating vector disease burdens pose significant global health risks, so innovative tools for targeting mosquitoes are critical. We engineered an antiviral strategy termed REAPER (vRNA Expression Activates Poisonous Effector Ribonuclease) that leverages the programmable RNA-targeting capabilities of CRISPR Cas13 and its potent collateral activity. Akin to a stealthy Trojan Horse hiding in stealth awaiting the presence of its enemy, REAPER remains concealed within the mosquito until an infectious blood meal is up taken. Upon target viral RNA infection, REAPER activates, triggering programmed destruction of its target arbovirus such as chikungunya. Consequently, Cas13 mediated RNA targeting significantly reduces viral replication and its promiscuous collateral activity can even kill infected mosquitoes. This innovative REAPER technology adds to an arsenal of effective molecular genetic tools to combat mosquito virus transmission.Competing Interest StatementO.S.A is a founder of both Agragene, Inc. and Synvect, Inc. with equity interest. The terms of this arrangement have been reviewed and approved by the University of California, San Diego in accordance with its conflict of interest policies. L.A is an adviser to Synvect, Inc and Biocentis Ltd., with financial interest in each. All other authors declare no competing interests.
Impact of randomised wmel Wolbachia deployments on notified dengue cases and insecticide fogging for dengue control in Yogyakarta City
24619C. Indriani, S. K. Tanamas, U. Khasanah, M. R. Ansari, Rubangi, W. Tantowijoyo, R. A. Ahmad, S. M. Dufault, N. P. Jewell, A. Utarini, C. P. Simmons and K. L. Anders, Glob Health Action, 16:2166650. 2023-01-26 09:27:00.
BACKGROUND: Releases of Wolbachia (wMel)-infected Aedes aegypti mosquitoes significantly reduced the incidence of virologically confirmed dengue in a previous cluster randomised trial in Yogyakarta City, Indonesia. Following the trial, wMel releases were extended to the untreated control areas, to achieve city-wide coverage of Wolbachia. OBJECTIVE: In this predefined analysis, we evaluated the impact of the wMel deployments in Yogyakarta on dengue hemorrhagic fever (DHF) case notifications and on the frequency of perifocal insecticide spraying by public health teams. METHODS: Monthly counts of DHF cases notified to the Yogyakarta District Health Office between January 2006 and May 2022 were modelled as a function of time-varying local wMel treatment status (fully- and partially-treated vs untreated, and by quintile of wMel prevalence). The frequency of insecticide fogging in wMel-treated and untreated areas was analysed using negative binomial regression. RESULTS: Notified DHF incidence was 83% lower in fully treated vs untreated periods (IRR 0.17 [95% CI 0.14, 0.20]), and 78% lower in areas with 80-100% wMel prevalence compared to areas with 0-20% wMel (IRR 0.23 [0.17, 0.30]). A similar intervention effect was observed at 60-80% wMel prevalence as at 80-100% prevalence (76% vs 78% efficacy, respectively). Pre-intervention, insecticide fogging occurred at similar frequencies in areas later randomised to wMel-treated and untreated arms of the trial. After wMel deployment, fogging occurred significantly less frequently in treated areas (IRR 0.17 [0.10, 0.30]). CONCLUSIONS: Deployments of wMel-infected Aedes aegypti mosquitoes resulted in an 83% reduction in the application of perifocal insecticide spraying, consistent with lower dengue case notifications in wMel-treated areas. These results show that the Wolbachia intervention effect demonstrated previously in a cluster randomised trial was also measurable from routine surveillance data.
Wolbachia RNase HI contributes to virus blocking in the mosquito Aedes aegypti
24468M. Hussain, G. Zhang, M. Leitner, L. M. Hedges and S. Asgari, iScience, 26:105836. 2023-01-15 08:41:00.
The endosymbiotic bacterium Wolbachia pipientis blocks replication of several arboviruses in transinfected Aedes aegypti mosquitoes. However, the mechanism of virus blocking remains poorly understood. Here, we characterized an RNase HI gene from Wolbachia, which is rapidly induced in response to dengue virus (DENV) infection. Knocking down w RNase HI using antisense RNA in Wolbachia-transinfected mosquito cell lines and A. aegypti mosquitoes led to increased DENV replication. Furthermore, overexpression of wRNase HI, in the absence of Wolbachia, led to reduced replication of a positive sense RNA virus, but had no effect on a negative sense RNA virus, a familiar scenario in Wolbachia-infected cells. Altogether, our results provide compelling evidence for the missing link between early Wolbachia-mediated virus blocking and degradation of viral RNA. These findings and the successful pioneered knockdown of Wolbachia genes using antisense RNA in cell line and mosquitoes enable new ways to manipulate and study the complex endosymbiont-host interactions.
New self-sexing Aedes aegypti strain eliminates barriers to scalable and sustainable vector control for governments and communities in dengue-prone environments
23796S. A. M. Spinner, Z. H. Barnes, A. M. Puinean, P. Gray, T. Dafa’alla, C. E. Phillips, C. Nascimento de Souza, T. F. Frazon, K. Ercit, A. Collado, N. Naish, E. Sulston, G. C. Ll. Phillips, K. K. Greene, M. Poletto, B. D. Sperry, S. A. Warner, N. R. Rose, G, Frontiers in Bioengineering and Biotechnology, 10. 2022-10-25 07:35:02.
For more than 60 years, efforts to develop mating-based mosquito control technologies have largely failed to produce solutions that are both effective and scalable, keeping them out of reach of most governments and communities in disease-impacted regions globally. High pest suppression levels in trials have yet to fully translate into broad and effective Aedes aegypti control solutions. Two primary challenges to date–the need for complex sex-sorting to prevent female releases, and cumbersome processes for rearing and releasing male adult mosquitoes–present significant barriers for existing methods. As the host range of Aedes aegypti continues to advance into new geographies due to increasing globalisation and climate change, traditional chemical-based approaches are under mounting pressure from both more stringent regulatory processes and the ongoing development of insecticide resistance. It is no exaggeration to state that new tools, which are equal parts effective and scalable, are needed now more than ever. This paper describes the development and field evaluation of a new self-sexing strain of Aedes aegypti that has been designed to combine targeted vector suppression, operational simplicity, and cost-effectiveness for use in disease-prone regions. This conditional, self-limiting trait uses the sex-determination gene doublesex linked to the tetracycline-off genetic switch to cause complete female lethality in early larval development. With no female progeny survival, sex sorting is no longer required, eliminating the need for large-scale mosquito production facilities or physical sex-separation. In deployment operations, this translates to the ability to generate multiple generations of suppression for each mosquito released, while being entirely self-limiting. To evaluate these potential benefits, a field trial was carried out in densely-populated urban, dengue-prone neighbourhoods in Brazil, wherein the strain was able to suppress wild mosquito populations by up to 96%, demonstrating the utility of this self-sexing approach for biological vector control. In doing so, it has shown that such strains offer the critical components necessary to make these tools highly accessible, and thus they harbour the potential to transition mating-based approaches to effective and sustainable vector control tools that are within reach of governments and at-risk communities who may have only limited resources.
Assessing single-locus CRISPR/Cas9-based gene drive variants in the mosquito Aedes aegypti via single generation crosses and modeling
23756W. Reid, A. E. Williams, I. Sanchez-Vargas, J. Lin, R. Juncu, K. E. Olson and A. W. E. Franz, G3 Genes|Genomes|Genetics, 2022-10-17 06:25:18.
Critical to the design of a single-locus autonomous GD is that the selected genomic locus is amenable to both GD and appropriate expression of the antiviral effector. In our study, we used reverse engineering to target two intergenic genomic loci, which had previously shown to be highly permissive for antiviral effector gene expression, and we further investigated the use of three promoters (nanos, β2-tubulin, or zpg) for Cas9 expression. We then quantified the accrual of insertions or deletions (indels) after single generation crossings, measured maternal effects, and assessed fitness costs associated with the various transgenic lines to model the rate of GD fixation. Overall, MGDrivE modeling suggested that when an autonomous GD is placed into an intergenic locus, the GD system will eventually be blocked by the accrual of GD blocking resistance alleles and ultimately be lost in the population. Moreover, while genomic locus and promoter selection were critically important for the initial establishment of the autonomous GD, it was the fitness of the GD line that most strongly influenced the persistence of the GD in the simulated population. As such, we propose that when autonomous CRISPR/Cas9 based GD systems are anchored in an intergenic locus, they temporarily result in a strong population replacement effect, but as GD-blocking indels accrue, the GD becomes exhausted due to the fixation of CRISPR resistance alleles.
GeneConvene Global Collaborative Webinar Series | Wolbachia Biology, Mechanisms and Applications 2022
23723David O'Brochta, GeneConvene Global Collaborative, 2022-10-15 06:57:26.
Intracellular and extracellular symbiotic/commensal bacteria have enormous potential when manipulated and deployed appropriately to serve as agents of control of insects and the pathogens they transmit. Wolbachia, an intracellular bacteria, is a well studied system and one that is used increasingly to control insect populations via cytoplasmic incompatibility and to alter the vectoral capacity of insect via pathogen inhibition. This webinar series will survey the applications of Wolbachia as a mosquito/dengue control intervention and the underlying biology that conditions its effectiveness.
Wolbachia wAlbB inhibit dengue and Zika infection in the mosquito Aedes aegypti with an Australian background
23714L. E. Hugo, G. Rašić, A. J. Maynard, L. Ambrose, C. Liddington, C. J. E. Thomas, N. S. Nath, M. Graham, C. Winterford, B. M. C. R. Wimalasiri-Yapa, Z. Xi, N. W. Beebe and G. J. Devine, PLOS Neglected Tropical Diseases, 16:e0010786. 2022-10-13 06:27:20.
Biological control of mosquito vectors using the endosymbiotic bacteria Wolbachia is an emerging strategy for the management of human arboviral diseases. We recently described the development of a strain of Aedes aegypti infected with the Wolbachia strain wAlbB (referred to as the wAlbB2-F4 strain) through simple backcrossing of wild type Australian mosquitoes with a wAlbB infected Ae. aegypti strain from the USA. Field releases of male wAlbB2-F4 mosquitoes resulted in the successful suppression of wild populations of mosquitoes in the trial sites by exploiting the strain’s Wolbachia-induced cytoplasmic incompatibility. We now demonstrate that the strain is resistant to infection by dengue and Zika viruses and is genetically similar to endemic Queensland populations. There was a fourfold reduction in the proportion of wAlbB2-F4 mosquitoes that became infected following a blood meal containing dengue 2 virus (16.7%) compared to wild type mosquitoes (69.2%) and a 6–7 fold reduction in the proportion of wAlbB2-F4 mosquitoes producing virus in saliva following a blood meal containing an epidemic strain of Zika virus (8.7% in comparison to 58.3% in wild type mosquitoes). Restriction-site Associated DNA (RAD) sequencing revealed that wAlbB2-F4 mosquitoes have > 98% Australian ancestry, confirming the successful introduction of the wAlbB2 infection into the Australian genomic background through backcrossing. Genotypic and phenotypic analyses showed the wAlbB2-F4 strain retains the insecticide susceptible phenotype and genotype of native Australian mosquitoes. We demonstrate that the Wolbachia wAlbB2-F4, in addition to being suitable for population suppression programs, can also be effective in population replacement programs given its inhibition of virus infection in mosquitoes. The ease at which a target mosquito population can be transfected with wAlbB2, while retaining the genotypes and phenotypes of the target population, shows the utility of this strain for controlling the Ae. aegypti mosquitoes and the pathogens they transmit.
Risk Assessment on the Release of Wolbachia-Infected Aedes aegypti in Yogyakarta, Indonesia
23707D. Buchori, A. Mawan, I. Nurhayati, A. Aryati, H. Kusnanto and U. K. Hadi, Insects, 13. 2022-10-12 08:16:52.
Wolbachia-infected Aedes aegypti is the latest technology that was developed to eliminate dengue fever. The Ministry of Research and Technology of the Republic of Indonesia (Kemenristekdikti) established an expert group to identify future potential risks that may occur over a period of 30 years associated with the release of Wolbachia-infected Ae. aegypti. The risk assessment consisted of identifying different hazards that may have impacts on humans and the environment. From the consensus among the experts, there were 56 hazards identified and categorized into 4 components, namely, ecological matters, efficacy in mosquito management, economic and sociocultural issues, and public health standards. There were 19 hazards in the ecological group. The overall likelihood in the ecology of the mosquito is very low (0.05), with moderate consequence (0.74), which resulted in negligible risk. For the efficacy in mosquito management group, there were 12 hazards that resulted in very low likelihood (0.11) with high consequence (0.85). The overall risk for mosquito management efficacy was very low (0.09). There were 14 hazards identified in the public health standard with very low likelihood (0.07), moderate consequence (0.50) and negligible risk (0.04). Lastly, 13 hazards were identified in the economic and sociocultural group with low likelihood (0.01) but of moderate consequence (0.5), which resulted in a very low risk (0.09). The risk severity level of the four components leading to the endpoint risk of “cause more harm” due to releasing Wolbachia-infected Ae. aegypti is negligible (0.01).
Combating Mosquito-Borne Diseases with CRISPR
23701N. Spahich, The Scientist, 2022-10-11 08:06:34.
Female mosquitoes are some of the deadliest organisms in the world due to their ability to spread infectious diseases through a simple bite. Mosquito-borne diseases such as yellow fever, Zika, Dengue fever, and malaria kill millions of humans every year, and there are limited therapeutics for their prevention and treatment. While in college, Omar Akbari worked as a public service intern testing the local mosquito population for human pathogens and eradicating these insects with chemicals. During this experience, he felt dissatisfied with the insecticide-based method of controlling mosquito population and wanted to find a better way to tackle the problem of mosquito-borne disease spread. With a multidisciplinary team in his laboratory at the University of California, San Diego, he now develops tools through genetic engineering techniques such as CRISPR to solve the world’s insect control problems.
Fitness costs of Wolbachia shift in locally-adapted Aedes aegypti mosquitoes
23703P. A. Ross and A. A. Hoffmann, Environmental Microbiology, 2022-10-06 08:10:07.
Aedes aegypti mosquito eggs can remain quiescent for many months before hatching, allowing populations to persist through unfavorable conditions. Aedes aegypti infected with the Wolbachia strain wMel have been released in tropical and subtropical regions for dengue control. wMel reduces the viability of quiescent eggs, but this physiological cost might be expected to evolve in natural mosquito populations that frequently experience stressful conditions. We found that the cost of wMel infection differed consistently between mosquitoes collected from different locations and became weaker across laboratory generations, suggesting environment-specific adaptation of mosquitoes to the wMel infection. Reciprocal crossing experiments show that differences in the cost of wMel to quiescent egg viability were mainly due to mosquito genetic background and not Wolbachia origin. wMel-infected mosquitoes hatching from long-term quiescent eggs showed partial loss of cytoplasmic incompatibility and female infertility, highlighting additional costs of long-term quiescence. Our study provides the first evidence for a shift in Wolbachia phenotypic effects following deliberate field release and establishment and it highlights interactions between Wolbachia infections and mosquito genetic backgrounds. The unexpected changes in fitness costs observed here suggest potential tradeoffs with undescribed fitness benefits of the wMel infection.
How We’re Reducing Disease With Genetically Modified Mosquitoes
23667V. Wise, HealthMatch, 2022-09-29 08:07:21.
We all know mosquitoes as those annoying insects we swat away from our faces. They carry diseases, so we don’t want them anywhere near us. There are over 200 types of wild mosquitoes bugging us across America and the U.S. territories. Approximately 12 types can spread disease, but most are “nuisance” mosquitoes, which don’t spread germs. Obviously, it’s hard to identify a tiny flying creature, so we need to keep them all away from us just in case. Aedes aegypti¹ is one of the most common mosquitoes in the U.S. that can spread disease. One of the best-known mosquito-borne diseases is malaria, but Aedes aegypti is associated with 54 viruses². West Nile virus, Zika, and dengue are just three diseases these mosquitoes transmit around the U.S With 1 in 150 people becoming seriously ill due to West Nile virus, sometimes fatally, what can we do to prevent mosquito bites?
Externalities modulate the effectiveness of the Wolbachia release programme
23611E. E. Ooi and A. Wilder-Smith, The Lancet Infectious Diseases, 2022-09-28 09:16:47.
Despite the remarkable outcome in Yogyakarta, the wMel approach also has some challenges. In particular, the extent to which ecological, weather, and other external factors influence the dissemination and establishment of wMel in complex urban environments remains unclear. Whether the high and sustained penetration rate of wMel and the efficacy in preventing dengue that was observed in Yogyakarta are readily reproducible in other regions of the world that are vulnerable to repeated outbreaks of such viral diseases is also unclear. We therefore welcome the study into the real-world effectiveness of large-scale wMel release in the urban setting of Rio de Janeiro.3 The study assessed the rate of wMel introgression at the neighbourhood level and its effect on the localised incidence of dengue and chikungunya. Mosquitoes were released over a 2·5-year period starting in August, 2017.
Estimating the effect of the wMel release programme on the incidence of dengue and chikungunya in Rio de Janeiro, Brazil: a spatiotemporal modelling study
23608G. Ribeiro dos Santos, B. Durovni, V. Saraceni, T. I. Souza Riback, S. B. Pinto, K. L. Anders, et al., The Lancet Infectious Diseases, 2022-09-28 09:07:02.
Summary Background Introgression of genetic material from species of the insect bacteria Wolbachia into populations of Aedes aegypti mosquitoes has been shown in randomised and non-randomised trials to reduce the incidence of dengue; however, evidence for the real-world effectiveness of large-scale deployments of Wolbachia-infected mosquitoes for arboviral disease control in endemic settings is still scarce. A large Wolbachia (wMel strain) release programme was implemented in 2017 in Rio de Janeiro, Brazil. We aimed to assess the effect of this programme on the incidence of dengue and chikungunya in the city. Methods 67 million wMel-infected mosquitoes were released across 28 489 locations over an area of 86·8 km2 in Rio de Janeiro between Aug 29, 2017 and Dec 27, 2019. Following releases, mosquitoes were trapped and the presence of wMel was recorded. In this spatiotemporal modelling study, we assessed the effect of the release programme on the incidence of dengue and chikungunya. We used spatiotemporally explicit mathematical models applied to geocoded dengue cases (N=283 270) from 2010 to 2019 and chikungunya cases (N=57 705) from 2016 to 2019. Findings On average, 32% of mosquitoes collected from the release zones between 1 month and 29 months after the initial release tested positive for wMel. Reduced wMel introgression occurred in locations and seasonal periods in which cases of dengue and chikungunya were historically high, with a decrease to 25% of mosquitoes testing positive for wMel during months in which disease incidence was at its highest. Despite incomplete introgression, we found that the releases were associated with a 38% (95% CI 32–44) reduction in the incidence of dengue and a 10% (4–16) reduction in the incidence of chikungunya. Interpretation Stable establishment of wMel in the geographically diverse, urban setting of Rio de Janeiro seems to be more complicated than has been observed elsewhere. However, even intermediate levels of wMel seem to reduce the incidence of disease caused by two arboviruses. These findings will help to guide future release programmes. Funding Bill & Melinda Gates Foundation and the European Research Council.
The Involvement of Atlastin in Dengue Virus and Wolbachia Infection in Aedes aegypti and Its Regulation by aae-miR-989
23637M. Hussain, T. Bradshaw, M. Lee and S. Asgari, Microbiology Spectrum, 2022-09-27 06:48:46.
Endoplasmic reticulum (ER)-shaping atlastin proteins (ATLs) have been demonstrated to play a functional role during flavivirus replication in mammalian cells. For dengue virus (DENV), atlastin is required in the formation of the replication organelles and RNA replication, virion assembly, production of the infectious virus particles, and trafficking or directing the association of vesicle packets with furin. Here, we investigated the involvement of atlastin in DENV replication in the mosquito Aedes aegypti and explored the possibility of its manipulation by the endosymbiotic bacterium Wolbachia to interfere with DENV replication. Results showed the expression of Ae. aegypti atlastin gene (AaATL) was upregulated in DENV-infected Aag2 cells, and its silencing led to reduced DENV replication. Contrary to our assumption that AaATL could be downregulated by Wolbachia, we did not find evidence for that in Wolbachia-infected cell lines, but this was the case in mosquitoes. Further, silencing AaATL did not have any effect on Wolbachia density. Our results also suggest that aae-miR-989 miRNA negatively regulates AaATL. The oversupply of the miRNA mimic led to reduced DENV replication consistent with the positive role of AaATL in DENV replication. Overall, the results favor AaATL’s involvement in DENV replication; however, there is no support that the protein is involved in Wolbachia-mediated DENV inhibition. In addition, the results contribute to discerning further possible overlapping functions of ATLs in mosquitoes and mammalian cells.
Bill Gates’ Colombian Mosquito Factory Breeding 30 Million Bacteria-Infected Mosquitos Per Week
23525anonymous, GREATGAMEINDIA, 2022-09-07 05:27:22.
Bill Gates’ Colombian ‘mosquito factory’ is breeding 30 million bacteria-infected mosquitos per week. The project’s objective appears to be to introduce Wolbachia into native mosquito populations by employing lab-bred mosquitoes, resulting in the infection of such populations. In a plant in Colombia, Bill Gates is currently producing 30 million bacterially-infected mosquitoes every week and he has threatened to “scale and deliver” the mosquitoes to “communities around the world.” As part of his World Mosquito Program (WMP), the Microsoft founder and self-declared World Health Czar has already invested $185 million in the establishment of the mosquito factory. What is the project’s stated purpose? In order to eradicate native mosquito populations thought to be responsible for dengue, zika, and other viral illnesses in humans, it is necessary to utilize mosquitoes that are infected with a bacteria that induces sterility.
Modified mosquito releases to fight dengue fever, chikungunya or yellow fever
23555Sewell, Tammy, OICANADIAN, 2022-09-05 14:35:46.
To date, only one technique based on genetically modified mosquitoes has been developed at an operational level, it is the RIDL technique (release of insects carrying a dominant lethal gene, or release of insects carrying a dominant lethality gene). Male mosquitoes which, unlike females, do not bite, are genetically modified. Their offspring die before reaching adulthood. This technique has received authorization from the US Environmental Protection Agency. Last spring, the private company Oxitec began a trial in Florida consisting in disseminating mosquito eggs Aedes aegypti (known to carry many viruses such as dengue fever, yellow fever, chikungunya and Zika) genetically modified in nature for three months.
An optimal control problem for dengue transmission model with Wolbachia and vaccination
23694J. Zhang, L. L. Liu, Y. Z. Li and Y. Wang, Communications In Nonlinear Science and Numerical Simulation, 116. 2022-09-02 07:47:59.
The release of Wolbachia-infected mosquitoes into the wild mosquitoes population is an excellent biological control strategy which can be effective against mosquito-borne infections. In this work, we propose a dengue transmission model that incorporates releasing Wolbachia into the wild mosquito population and vaccinating human population. We analyze the basic reproduction number, the existence and stability of the equilibria, and carry out the sensitivity analysis to quantify the effects of parameters on the basic reproduction number. The analysis shows that the basic reproduction number determines the stability of two equilibria, and two transmission probabilities are positively correlated with the basic reproduction number, especially, the transmission probability of human being infected byWolbachia-infected mosquitoes is more sensitive than that of wild mosquitoes. Based on an integrated control strategy for the prevention of dengue fever (vaccination, using mosquito nets, improved treatment of dengue and spraying insecticides), we derive the necessary conditions for the optimal control problem using Pontryagin's Maximum Principle and carry out numerical simulations by MATLAB. Finally, the cost-effectiveness analysis of several control strategies is examined to determine the most feasible strategy. It shows that the most cost-effective integrated strategy is vaccination, using mosquito nets and spraying insecticides. (c) 2022 Elsevier B.V. All rights reserved.
World Mosquito Day: Can genetic modification techniques quash the menace?
23446CNBCTV18, CNBC TV18, 2022-08-20 09:54:03.
Genetically modified (GM) mosquitoes are prepared in labs and are supposed to fight the Aedes aegypti mosquitoes which spread viruses including dengue, Zika, and chikungunya. Billions have apparently been successfully released in the US, Brazil, the Cayman Islands, Panama, and India.
Outbreaks of arboviruses, biotechnological innovations and vector control: facing the unexpected
23438C. Boëte, Innovative Strategies for Vector Control, 6:219-231. 2022-08-19 09:19:15.
Outbreaks of arboviruses have occurred in the last decades in many places around the world and a variety of responses have been taken in order to control them. Responses ranged from vaccination campaigns to the use of conventional vector control methods. Innovative approaches relying on biotechnological novelties, often still under development, have been considered despite the lack of solid evidence of their efficacy. While discussing these different aspects of the fight against vector-borne diseases with a focus on the context of outbreaks, this chapter considers the social and ethical aspects related to both the rhetoric and the discussion about the implementation of new and innovative approaches.
Changing mosquito genes, spreading bacteria: Science sees success vs dengue
23421C. E. Baclig, INQUIRER.NET, 2022-08-10 08:51:03.
Wolbachia, according to WMP, are extremely common bacteria that occur naturally in 50 percent of insect species, including mosquitoes, fruit flies, moths, dragonflies, and butterflies. Aedes aegypti or dengue-carrying mosquitoes, however, do not normally carry Wolbachia. Studies showed that the bacteria make it difficult for viruses, such as dengue, Zika, chikungunya, and yellow fever, to reproduce inside the Aedes aegypti mosquitoes—making the mosquitoes much less likely to spread viruses when they bite people. “This means that when Aedes aegypti mosquitoes carry natural Wolbachia bacteria, the transmission of viruses like dengue, Zika, chikungunya, and yellow fever is reduced,” the organization explained. The WMP breeds Wolbachia-carrying mosquitoes and releases them into areas hit by mosquito-borne diseases. This means there will be “less risk of disease in communities where Wolbachia is established in the local mosquito population.”
Aedes aegypti and Ae. albopictus microbiome/virome: new strategies for controlling arboviral transmission?
23413M. Gómez, D. Martinez, M. Muñoz and J. D. Ramírez, Parasites and Vectors, 15:287. 2022-08-09 12:21:12.
Aedes aegypti and Aedes albopictus are the main vectors of highly pathogenic viruses for humans, such as dengue (DENV), chikungunya (CHIKV), and Zika (ZIKV), which cause febrile, hemorrhagic, and neurological diseases and remain a major threat to global public health. The high ecological plasticity, opportunistic feeding patterns, and versatility in the use of urban and natural breeding sites of these vectors have favored their dispersal and adaptation in tropical, subtropical, and even temperate zones. Due to the lack of available treatments and vaccines, mosquito population control is the most effective way to prevent arboviral diseases. Resident microorganisms play a crucial role in host fitness by preventing or enhancing its vectorial ability to transmit viral pathogens. High-throughput sequencing and metagenomic analyses have advanced our understanding of the composition and functionality of the microbiota of Aedes spp. Interestingly, shotgun metagenomics studies have established that mosquito vectors harbor a highly conserved virome composed of insect-specific viruses (ISV). Although ISVs are not infectious to vertebrates, they can alter different phases of the arboviral cycle, interfering with transmission to the human host. Therefore, this review focuses on the description of Ae. aegypti and Ae. albopictus as vectors susceptible to infection by viral pathogens, highlighting the role of the microbiota-virome in vectorial competence and its potential in control strategies for new emerging and re-emerging arboviruses.
Studies on the fitness characteristics of wMel- and wAlbB-introgressed Aedes aegypti (Pud) lines in comparison with wMel- and wAlbB-transinfected Aedes aegypti (Aus) and wild-type Aedes aegypti (Pud) lines
23485C. Sadanandane, K. Gunasekaran, D. Panneer, S. K. Subbarao, M. Rahi, B. Vijayakumar, V. Athithan, A. Sakthivel, S. Dinesh and P. Jambulingam, Frontiers in Microbiology, 13:947857. 2022-08-05 07:02:55.
Wolbachia, an intracellular maternally transmitted endosymbiont, has been shown to interfere with the replication of dengue virus in Aedes aegypti mosquitoes. The Wolbachia-transinfected Ae. aegypti has been currently released in many countries to test its effectiveness in preventing the transmission of dengue virus. ICMR-Vector Control Research Centre in collaboration with World Mosquito Program Monash University, Australia, has generated two new Wolbachia-introgressed Ae. aegypti Puducherry (Pud) lines via backcrossing Ae. aegypti females of Australian (Aus) strains, infected with wMel and wAlbB Wolbachia with wild-type Ae. aegypti Puducherry (Pud) males. Wolbachia infections are known to induce a fitness cost and confer benefit on the host mosquito populations that will influence spread of the Wolbachia into native wild mosquito populations during the field release. Hence, the induced fitness cost or benefit/advantage in the two newly generated Ae. aegypti (Pud) lines was assessed in the laboratory in comparison with the wild-type Ae. aegypti (Pud) strain. In addition, maternal transmission (MT) efficiency, induced cytoplasmic incompatibility (CI), and insecticide resistance status of the two (Pud) lines were determined to assess the likely frequency of wMel and wAlbB infections in the native wild population after field invasion. The study shows that wMel and wAlbB infections did not induce any fitness cost on the two newly generated (Pud) lines. Rather, in terms of wing length, fecundity, egg hatch rate, and adult survival, the Wolbachia introgression conferred fitness benefits on the (Pud) lines compared to uninfected Wolbachia free wild Ae. aegypti population. wMel and wAlbB exhibited a high maternal transmission (99-100%) and induced nearly complete (98-100%) cytoplasmic incompatibility. Both the (Pud) lines were resistant to deltamethrin, malathion, DDT, and temephos, and the level of resistance was almost the same between the two lines as in the wild type. Overall, the stable association of wMel and wAlbB established with Ae. aegypti and the reproductive advantages of the (Pud) lines encourage a pilot release in the field for population replacement potential.
Intron-derived small RNAs for silencing viral RNAs in mosquito cells
23054P. Y. L. Tng, L. Z. Carabajal Paladino, M. A. E. Anderson, Z. N. Adelman, R. Fragkoudis, R. Noad and L. Alphey, PLOS Neglected Tropical Diseases, 16:e0010548. 2022-06-23 15:14:23.
Aedes aegypti and Ae. albopictus are the main vectors of mosquito-borne viruses of medical and veterinary significance. Many of these viruses have RNA genomes. Exogenously provided, e.g. transgene encoded, small RNAs could be used to inhibit virus replication, breaking the transmission cycle. We tested, in Ae. aegypti and Ae. albopictus cell lines, reporter based strategies for assessing the ability of two types of small RNAs to inhibit a chikungunya virus (CHIKV) derived target. Both types of small RNAs use a Drosophila melanogasterpremiRNA-1 based hairpin for their expression, either with perfect base-pairing in the stem region (shRNA-like) or containing two mismatches (miRNA-like). The pre-miRNA-1 stem loop structure was encoded within an intron; this allows co-expression of one or more proteins, e.g. a fluorescent protein marker tracking the temporal and spatial expression of the small RNAs in vivo. Three reporter-based systems were used to assess the relative silencing efficiency of ten shRNA-like siRNAs and corresponding miRNA-like designs. Two systems used a luciferase reporter RNA with CHIKV RNA inserted either in the coding sequence or within the 3’ UTR. A third reporter used a CHIKV derived split replication system. All three reporters demonstrated that while silencing could be achieved with both miRNA-like and shRNA-like designs, the latter were substantially more effective. Dcr-2 was required for the shRNA-like siRNAs as demonstrated by loss of inhibition of the reporters in Dcr-2 deficient cell lines. These positive results in cell culture are encouraging for the potential use of this pre-miRNA-1-based system in transgenic mosquitoes.
Modifying mosquitoes to suppress disease transmission: Is the long wait over?
22854J. R. Powell, Genetics, 2022-06-02 08:31:17.
For more than 50 years it has been a dream of medical entomologists and public health workers to control diseases like malaria and dengue fever by modifying, through genetics and other methods, the arthropods that transmit them to humans. A brief synopsis of the history of these efforts as applied to mosquitoes is presented; none proved to be effective in reducing disease prevalence. Only in the last few years have novel approaches been developed or proposed that indicate the long wait may be over. Three recent developments are particularly promising: CRISPR-Cas9 driven genetic modification, shifting naturally occurring allele frequencies, and microbe-based modifications. The last is the furthest along in implementation. Dengue fever incidence has been reduced between 40% and 96% in 4 different regions of the world where Wolbachia-infected Aedes aegypti have been established in the field. It is not yet clear how sustainable such control programs will prove to be, but there is good reason for optimism. In light of this, the time is ripe for reinvigorated research on vectors, especially genetics. Vector-borne diseases primarily affect under-developed countries and thus have not received the attention they deserve from wealthier countries with well-developed and funded biomedical research establishments.
Modeling the impact of genetically modified male mosquitoes in the spatial population dynamics of Aedes aegypti
23212M. R. da Silva, P. H. G. Lugão, F. Prezoto and G. Chapiro, Scientific Reports, 12:9112. 2022-06-01 06:29:36.
The mosquito Aedes aegypti is the primary vector of diseases such as dengue, Zika, chikungunya, and yellow fever. Improving control techniques requires a better understanding of the mosquito’s life cycle, including spatial population dynamics in endemic regions. One of the most promising techniques consists of introducing genetically modified male mosquitoes. Several models proposed to describe this technique present mathematical issues or rely on numerous parameters, making their application challenging to real-world situations. We propose a model describing the spatial population dynamics of the Aedes aegypti in the presence of genetically modified males. This model presents some mathematical improvements compared to the literature allowing deeper mathematical analysis. Moreover, this model relies on few parameters, which we show how to obtain or estimate from the literature. Through numerical simulations, we investigate the impacts of environmental heterogeneity, the periodicity of genetically modified male releases, and released genetically modified males quantity on the population dynamics of Aedes aegypti. The main results point to that the successful application of this vector control technique relies on releasing more than a critical amount of modified males with a frequency exceeding a specific critical value.
Elimination of a closed population of the yellow fever mosquito, Aedes aegypti, through releases of self-limiting male mosquitoes
22519P. B. Patil, S. K. Dasgupta, K. Gorman, A. Pickl-Herk, M. Puinean, A. McKemey, B. Char, U. B. Zehr and S. R. Barwale, PLOS Neglected Tropical Diseases, 16:e0010315. 2022-05-16 09:19:04.
Author summary Aedes aegypti L. species is the primary vector responsible for transmission of the dengue virus worldwide including chikungunya, yellow fever and Zika virus. The experiment presented in the manuscript represents a study undertaken to demonstrate suppression of the wild type Ae. aegypti population in large outdoor field cages with natural exposure to the environment (physically-contained field cage facility) by sustained releases of male adults of OX513A Ae. aegypti strain. This investigation is a phase-2 contained study as per the World Health Organization guidelines for evaluation of genetically modified organisms and was recommended by the Indian regulatory board. This experiment demonstrates suppression of wild type Ae. aegypti population by sustained releases of OX513A male adults in a contained facility. The prospect of the project is to demonstrate and implement the technology for controlling/suppression of the Ae. aegypti vector in the open field environment.
Simple, sensitive, and cost-effective detection of wAlbB Wolbachia in Aedes mosquitoes, using loop mediated isothermal amplification combined with the electrochemical biosensing method
22480P. Thayanukul, B. Lertanantawong, W. Sirawaraporn, S. Charasmongkolcharoen, T. Chaibun, R. Jittungdee and P. Kittayapong, PLOS Neglected Tropical Diseases, 16:e0009600. 2022-05-13 07:05:35.
Author summary Mosquito-borne diseases such as dengue, chikungunya, zika, and yellow fever are transmitted to humans mainly by the bites of Aedes aegypti mosquitoes. Controlling the vectors of these diseases relies mostly on the use of insecticides. However, the efficiency has been reduced through the development of insecticide resistance in mosquitoes. Wolbachia is an endosymbiotic bacterium that is naturally found in 40% of insects, including mosquitoes. The bacterium can protect its insect hosts from viral infections and can also cause sterility in insect host populations, therefore, providing an opportunity to use it for human disease control. Application of a Wolbachia trans-infected mosquitoes needs simple, rapid and sensitive methods for detecting the bacteria in released mosquitoes. In this paper, we develop the methods of LAMP and BIOSENSORS for detecting wAlbB Wolbachia in mosquitoes. Our positive LAMP reaction can be visualized by color change from violet to blue at a sensitivity of ≥ 10 pg of genomic DNA. When used in combination with the BIOSENSOR method, the sensitivity increases a millionfold without losing specificity. Our study suggests that both developed methods, either used in combination or stand-alone, are efficient and cost-effective, hence, they could be applied for routine surveys of Wolbachia in mosquito control programs that use Wolbachia-based approaches.
Mosquitoes Genetically Modified to Stop Disease Pass Early Test
22448L. Rapaport, WebMD, 2022-05-09 08:57:53.
Genetically modified mosquitoes released in the U.S. appear to have passed an early test that suggests they might one day help reduce the population of insects that transmit infectious diseases. As part of the test, scientists released nearly 5 million genetically engineered male Aedes aegypti mosquitoes over the course of 7 months in the Florida Keys. Male mosquitoes don’t bite people, and these were also modified so they would transmit a gene to female offspring that causes them to die before they can reproduce. In theory, this means the population of Aedes aegypti mosquitoes would die off over time, so they wouldn’t spread diseases any more. The goal of this pilot project in Florida was to see if these genetically modified male mosquitoes could successfully mate with females in the wild, and to confirm whether their female offspring would indeed die before they could reproduce. On both counts, the experiment was a success, Oxitec, the biotechnology company developing these engineered Aedes aegypti mosquitoes, said in a webina
Genetically Modified Mosquitoes May Protect The World From Disease
22213J. R. Learn, DISCOVER, 2022-05-04 15:29:48.
Forget lions, hippos or venomous spiders. Aedes aegypti mosquitoes may be among the deadliest wildlife in the world. Their bite is relatively harmless in normal circumstances. But many of these mosquitoes carry diseases they transmit from the blood of one host to another, including Zika, chikungunya, dengue and yellow fever. Like the related tiger mosquito that also carries these diseases, the Ae. aegypti are distinguished by black and white stripes along their legs. These mosquitoes thrive in urban areas, which makes the spread of the diseases they carry particularly insidious. They typically breed in small volumes of water, like in discarded tires and flower pots. But a new genetically engineered technology can get the mosquitoes to breed themselves out of existence. “We want to have a tool that’s going to have a real impact on disease transmission, and we want it to be accessible,” says Nathan Rose, head of regulatory affairs at Oxitec. “Our real focus has been on finding environmentally friendly ways of controlling pests.”
Transient Introgression of Wolbachia into Aedes aegypti Populations Does Not Elicit an Antibody Response to Wolbachia Surface Protein in Community Members
22655E. Lee, T. Hien Nguyen, T. Yen Nguyen, S. Nam Vu, N. Duong Tran, L. Trung Nghia, Q. Mai Vien, T. Dong Nguyen, R. Kriiger Loterio, I. Iturbe-Ormaetxe, H. A. Flores, S. L. O'Neill, D. Anh Dang, C. P. Simmons and J. E. Fraser, Pathogens, 11. 2022-05-03 06:41:58.
Wolbachia is an endosymbiotic bacterium that can restrict the transmission of human pathogenic viruses by Aedes aegypti mosquitoes. Recent field trials have shown that dengue incidence is significantly reduced when Wolbachia is introgressed into the local Ae. aegypti population. Female Ae. aegypti are anautogenous and feed on human blood to produce viable eggs. Herein, we tested whether people who reside on Tri Nguyen Island (TNI), Vietnam developed antibodies to Wolbachia Surface Protein (WSP) following release of Wolbachia-infected Ae. aegypti, as a measure of exposure to Wolbachia. Paired blood samples were collected from 105 participants before and after mosquito releases and anti-WSP titres were measured by ELISA. We determined no change in anti-WSP titres after ~30 weeks of high levels of Wolbachia-Ae. aegypti on TNI. These data suggest that humans are not exposed to the major Wolbachia surface antigen, WSP, following introgression of Wolbachia-infected Ae. aegypti mosquitoes.
International shipments of Wolbachia-infected mosquito eggs: towards the scaling-up of World Mosquito Program operations
23390J. A. Denton, D. A. Joubert, A. A. Goundar and J. R. L. Gilles, Scientific and Technical Review, 41:91-99. 2022-05-01 08:01:14.
The Wolbachia insect control method, employed by the World Mosquito Program (WMP), relies on introgressing Wolbachia through target Aedes aegypti populations to reduce the incidence of dengue. Since 2010, the WMP has been producing Wolbachia-infected mosquitoes at numerous sites across the globe for release in 11 countries. As the technology has matured, greater focus has been placed on mosquito production at larger central facilities for transport to remote release sites, both domestically and internationally. Of particular note is the production of Wolbachia-infected mosquitoes at the WMP's Australian production facility for successful international deployments in Fiji, Vanuatu, Kiribati and Sri Lanka. This requires careful management of both production and supply-chain processes to ensure that the quality of the mosquito eggs, specifically the hatch rate and Wolbachia infection rate, is maintained. To ensure the cost-effectiveness and scalability of the Wolbachia method, these processes will be further refined to facilitate deployment from large centralised production facilities.
Role of CRISPR Technology in Gene Editing of Emerging and Re-emerging Vector Borne Disease
21811K. K. Mahto, P. Prasad, M. Kumar, H. Dubey and A. Ranjan, Recent Advances in Pathogen Interactions, Immunity, and Vector Control Strategies, 2022-04-23 05:49:18.
Vector borne diseases are rampant across the world. Due to spread and estab-lishment of vector species in different geographical areas, vector adaptation and resistance towards many insecticides the only option left is vector control for vari-ous vector borne diseases. Recent advancement in the field of genome editing have provided a variety of tools like, CRISPR, a novel genome editing techniques which can be applied for the control and prevention of many deadly diseases like dengue, chikungunya, filariasis, Japanese encephalitis and Zika. The present chapter is aimed to discuss the recent advancement in genome editing tools such as, their applica-tion, challenges, and limitations in vector control. Additionally, this chapter would potentially be advantageous to understand the hurdles, knowledge gaps in eliminating vector borne disease.
Aedes aegypti abundance and insecticide resistance profiles in the applying Wolbachia to eliminate dengue trial
21790W. Tantowijoyo, S. K. Tanamas, I. Nurhayati, S. Setyawan, N. Budiwati, I. Fitriana, I. Ernesia, D. S. Wardana, E. Supriyati, E. Arguni, Y. Meitika, E. Prabowo, B. Andari, B. R. Green, L. Hodgson, E. Rancès, P. A. Ryan, S. L. O'Neill, K. L. Anders, M. R. A, PLOS Neglected Tropical Diseases, 16:e0010284. 2022-04-20 07:01:27.
The Applying Wolbachia to Eliminate Dengue (AWED) trial was a parallel cluster randomised trial that demonstrated Wolbachia (wMel) introgression into Ae. aegypti populations reduced dengue incidence. In this predefined substudy, we compared between treatment arms, the relative abundance of Ae. aegypti and Ae. albopictus before, during and after wMel-introgression. Between March 2015 and March 2020, 60,084 BG trap collections yielded 478,254 Ae. aegypti and 17,623 Ae. albopictus. Between treatment arms there was no measurable difference in Ae. aegypti relative abundance before or after wMel-deployments, with a count ratio of 0.96 (95% CI 0.76, 1.21) and 1.00 (95% CI 0.85, 1.17) respectively. More Ae. aegypti were caught per trap per week in the wMel-intervention arm compared to the control arm during wMel deployments (count ratio 1.23 (95% CI 1.03, 1.46)). Between treatment arms there was no measurable difference in the Ae. albopictus population size before, during or after wMel-deployment (overall count ratio 1.10 (95% CI 0.89, 1.35)). We also compared insecticide resistance phenotypes of Ae. aegypti in the first and second years after wMel-deployments. Ae. aegypti field populations from wMel-treated and untreated arms were similarly resistant to malathion (0.8%), permethrin (1.25%) and cyfluthrin (0.15%) in year 1 and year 2 of the trial. In summary, we found no between-arm differences in the relative abundance of Ae. aegypti or Ae. albopictus prior to or after wMel introgression, and no between-arm difference in Ae. aegypti insecticide resistance phenotypes. These data suggest neither Aedes abundance, nor insecticide resistance, confounded the epidemiological outcomes of the AWED trial.
A metapopulation approach to identify targets for Wolbachia-based dengue control
22221A. Reyna-Lara, D. Soriano-Paños, J. H. Arias-Castro, H. J. Martínez and J. Gómez-Gardeñes, Chaos, 32:041105. 2022-04-18 15:42:29.
Over the last decade, the release of Wolbachia-infected Aedes aegypti into the natural habitat of this mosquito species has become the most sustainable and long-lasting technique to prevent and control vector-borne diseases, such as dengue, zika, or chikungunya. However, the limited resources to generate such mosquitoes and their effective distribution in large areas dominated by the Aedes aegypti vector represent a challenge for policymakers. Here, we introduce a mathematical framework for the spread of dengue in which competition between wild and Wolbachia-infected mosquitoes, the cross-contagion patterns between humans and vectors, the heterogeneous distribution of the human population in different areas, and the mobility flows between them are combined. Our framework allows us to identify the most effective areas for the release of Wolbachia-infected mosquitoes to achieve a large decrease in the global dengue prevalence.
Potential Adverse Effects of GE Mosquitoes Unknown
21773B. Giuffre, The Epoch Times, 2022-04-17 08:04:34.
“Safe and sustainable.” That’s what Oxitec, a British biological pest control company, calls its genetically modified (GM) or genetically engineered (GE) mosquito pesticide product. The company claims its product is nontoxic to humans and animals and won’t harm beneficial insects such as bees and butterflies. The experiment’s goal is to test the use of GE mosquitoes for reducing the transmission of diseases such as dengue, Zika, chikungunya, and yellow fever. The method of action is post-CRISPR, but uses similar gene engineering technology—inserting a double whammy into the Aedes aegypti male mosquito: a lethal gene and a fluorescent gene (for tracking). “The goal here is not to kill mosquitoes,” said epidemiologist Thomas Scott of the GE mosquito projects in Science magazine, “It’s to prevent people from getting infected and sick and dying.”
Genetically Modified Mosquitoes May Be Released in California, Experts Express Concern
21719Z. Papadakis, NEWSMAX, 2022-04-11 09:25:49.
Millions of genetically engineered mosquitos could soon be set loose in California in an effort to curb the disease-carrying Aedes aegypti mosquito population — but some experts are concerned that it could backfire. On March 7, Oxitec, a private company, obtained a permit from the U.S. Environmental Protection Agency to release its mosquitos in specific districts in Florida and California. The company reasoned that its genetically modified insects could help to save the world half of the world's population from the invasive Aedes aegypti mosquito which, according to Oxitec, increases the risk of transmission of dengue, chikungunya, Zika, yellow fever, and other diseases. "Given the growing health threat this mosquito poses across the U.S., we're working to make this technology available and accessible," Grey Frandsen, CEO of Oxitec, said in a statement. "These pilot programs, wherein we can demonstrate the technology's effectiveness in different climate settings, will play an important role in doing so. We look forward to getting to work this year."
Genetic Stability and Fitness of Aedes aegypti Red-Eye Genetic Sexing Strains With Pakistani Genomic Background for Sterile Insect Technique Applications
22452M. Misbah-ul-Haq, D. O. Carvalho, L. D. de la Fuente, A. A. Augustinos and K. Bourtzis, Frontiers in Bioengineering and Biotechnology, 10. 2022-03-31 09:37:56.
The mosquito species Aedes aegypti is the primary transmitter of viruses that cause endemic diseases like dengue in Pakistan. It is also a cause of other vector-borne diseases like yellow fever, Zika fever, and chikungunya, which significantly impact human health worldwide. In the absence of efficient vaccines (except for yellow fever) or drugs, vector control methods, such as the sterile insect technique (SIT), have been proposed as additional tools for the management of these diseases. Mosquito SIT programs are based on the release of sterile males and it is important female releases to be ideally zero or to be kept at a minimum, since females are the ones that bite, blood-feed and transmit pathogens. Recently, an Ae. aegypti genetic sexing strain (GSS), with and without a recombination-suppressing inversion (Inv35), was developed using the eye color as a selectable marker, with males having black eyes and females red eyes. In the present study, we introgressed the sexing features and the Inv35 of the Ae. aegypti red-eye GSS into the Pakistani genomic background aiming to their future use for SIT applications in the country. Both introgressed strains, the Red-eye GSS-PAK and the Red-eye GSS/Inv35-PAK, were evaluated in respect to their genetic stability and biological quality by assessing parameters like recombination rate, fecundity, fertility, pupal and adult recovery, time of development, pupal weight, survival, and flight ability in comparison with a wild Pakistani population (PAK). The results suggest that the sexing features and the recombination suppression properties of Inv35 were not affected after their introgression into the local genomic background; however, some biological traits of the two newly constructed strains were affected, positively or negatively, suggesting that a thorough quality control analysis should be performed after the introgression of a GSS into a new genomic background prior to its use in SIT field trials or applications. The importance of using GSS with local genomic background for SIT applications against Aedes aegypti is also discussed.
Special mosquitos to combat dengue fever in Binh Duong
21249L. Phuong, VN Express, 2022-03-25 08:39:12.
Capsules containing mosquito eggs resistant to dengue fever viruses were released in southern Binh Duong's Thu Dau Mot Town on Thursday to help control the disease. The Wolbachia Project in southern Vietnam, conducted by the World Mosquito Program and collaborators, seeks to release mosquitos infected with the Wolbachia bacteria into the environment. The bacteria, a natural pathogen to several insects, would compete with viruses like dengue, Zika, chikungunya and yellow fever found inside mosquitos, thus making it harder for viruses to replicate and for mosquitos to spread the viruses to humans.
EVITA Dengue: a cluster-randomized controlled trial to EValuate the efficacy of Wolbachia-InfecTed Aedes aegypti mosquitoes in reducing the incidence of Arboviral infection in Brazil
20526M. H. Collins, G. E. Potter, M. D. T. Hitchings, E. Butler, M. Wiles, J. K. Kennedy, S. B. Pinto, A. B. M. Teixeira, A. Casanovas-Massana, N. G. Rouphael, G. A. Deye, C. P. Simmons, L. A. Moreira, M. L. Nogueira, D. A. T. Cummings, A. I. Ko, M. M. Teixeir, Trials, 23:185. 2022-03-02 08:20:38.
BACKGROUND: Arboviruses transmitted by Aedes aegypti including dengue, Zika, and chikungunya are a major global health problem, with over 2.5 billion at risk for dengue alone. There are no licensed antivirals for these infections, and safe and effective vaccines are not yet widely available. Thus, prevention of arbovirus transmission by vector modification is a novel approach being pursued by multiple researchers. However, the field needs high-quality evidence derived from randomized, controlled trials upon which to base the implementation and maintenance of vector control programs. Here, we report the EVITA Dengue trial design (DMID 17-0111), which assesses the efficacy in decreasing arbovirus transmission of an innovative approach developed by the World Mosquito Program for vector modification of Aedes mosquitoes by Wolbachia pipientis. METHODS: DMID 17-0111 is a cluster-randomized trial in Belo Horizonte, Brazil, with clusters defined by primary school catchment areas. Clusters (n = 58) will be randomized 1:1 to intervention (release of Wolbachia-infected Aedes aegypti mosquitoes) vs. control (no release). Standard vector control activities (i.e., insecticides and education campaigns for reduction of mosquito breeding sites) will continue as per current practice in the municipality. Participants (n = 3480, 60 per cluster) are children aged 6-11 years enrolled in the cluster-defining school and living within the cluster boundaries who will undergo annual serologic surveillance for arboviral infection. The primary objective is to compare sero-incidence of arboviral infection between arms. DISCUSSION: DMID 17-0111 aims to determine the efficacy of Wolbachia-infected mosquito releases in reducing human infections by arboviruses transmitted by Aedes aegypti and will complement the mounting evidence for this method from large-scale field releases and ongoing trials. The trial also represents a critical step towards robustness and rigor for how vector control methods are assessed, including the simultaneous measurement and correlation of entomologic and epidemiologic outcomes. Data from this trial will inform further the development of novel vector control methods. TRIAL REGISTRATION: ClinicalTrials.gov NCT04514107 . Registered on 17 August 2020 Primary sponsor: National Institute of Health, National Institute of Allergy and Infectious Diseases.
Regulation of genetically engineered (GE) mosquitoes as a public health tool: a public health ethics analysis
20480Z. Meghani, Globalization and Health, 18:21. 2022-02-21 08:33:18.
In recent years, genetically engineered (GE) mosquitoes have been proposed as a public health measure against the high incidence of mosquito-borne diseases among the poor in regions of the global South. While uncertainties as well as risks for humans and ecosystems are entailed by the open-release of GE mosquitoes, a powerful global health governance non-state organization is funding the development of and advocating the use of those bio-technologies as public health tools.
Assessing Aedes aegypti candidate genes during viral infection and Wolbachia-mediated pathogen blocking
20315L. T. Sigle, M. Jones, M. Novelo, S. A. Ford, N. Urakova, K. Lymperopoulos, R. T. Sayre, Z. Xi, J. L. Rasgon and E. A. McGraw, Insect Molecular Biology, 2022-02-03 09:03:09.
Abstract One approach to control dengue virus transmission is the symbiont Wolbachia, that limits viral infection in mosquitoes. Despite plans for its widespread use in Aedes aegypti, Wolbachia's mode of action remains poorly understood. Many studies suggest that the mechanism is likely multifaceted, involving aspects of immunity, cellular stress, and nutritional competition. A previous study from our group used artificial selection to identify a new mosquito candidate gene related to viral blocking; alpha-mannosidase-2a (alpha-Mann-2a) with a predicted role in protein glycosylation. Protein glycosylation pathways tend to be involved in complex host-viral interactions; however, the function of alpha-mannosidases has not been described in mosquito-virus interactions. We examined alpha-Mann-2a expression in response to virus and Wolbachia infections and whether reduced gene expression, caused by RNA interference (RNAi), affected viral loads. We show that dengue virus (DENV) infection affects the expression of alpha-Mann-2a in a tissue- and time-dependent manner, whereas Wolbachia infection had no effect. In the midgut, DENV prevalence increased following knockdown of alpha-Mann-2a expression in Wolbachia-free mosquitoes, suggesting that alpha-Mann-2a interferes with infection. Expression knockdown had the same effect on the togavirus chikungunya virus (CHIKV), indicating that alpha-Mann-2a may have broad antivirus effects in the midgut. Interestingly, we were unable to knockdown the expression in Wolbachia-infected mosquitoes. We also provide evidence that alpha-Mann-2a may affect the transcriptional level of another gene predicted to be involved in viral blocking and cell adhesion; cadherin87a. These data support the hypothesis that glycosylation and adhesion pathways may broadly be involved in viral infection in Ae. aegypti. This article is protected by copyright. All rights reserved.
A flavivirus-inducible gene expression system that modulates broad-spectrum antiviral activity against dengue and Zika viruses
20281S.-C. Weng, Y.-X. Zhou and S.-H. Shiao, Insect Biochemistry and Molecular Biology, 142:103723. 2022-02-02 11:40:32.
Incidence of dengue virus (DENV) and Zika virus (ZIKV), two mosquito-borne flaviviruses, is increasing in large parts of the world. Vaccination and medication for these diseases are unsatisfactory. Here, we developed a novel antiviral approach, using a virus-inducible gene expression system, to block virus replication and transmission. Constructs containing the smallest replication units of dengue virus serotype 2 (DENV2) with negative-stranded DENV2 artificial genomes and genes of interest were established in an Aedes aegypti cell line, resulting in expression of target genes after DENV2 infection. Green fluorescent protein (GFP) assays confirmed the system was virus-inducible. When we used one of two apoptosis-related genes, A. aegypti michelob_x (AaMx) and inhibitor of apoptosis (IAP)-antagonist michelob_x-like protein (AaIMP) instead of GFP, the production of viral RNA and proteins were inhibited for all five viruses tested (DENV1–4 and ZIKV), and effector caspase activity was induced. The system thus inhibited the production of infectious virus particles in vitro, and in mosquitoes it did so after DENV2 infection. This is a novel broad-spectrum antiviral approach using a flavivirus-inducible gene-expression system, which could lead to new avenues for mosquito-borne disease control.
CRISPR Technology Can Eliminate Disease-Spreading Mosquitoes
20133S. Krishana, Now, 2022-01-19 13:10:41.
Scientists have uncovered a new technique they call the “precision-guided sterile insect technique,” or pgSIT. While most CRISPR procedures affect organisms that spread diseases by passing a gene change down generations, this system is more limited. It targets male mosquito genes that are linked to fertility. As a result of changing these genes, any offspring these mosquitoes have would be infertile. “pgSIT is a new scalable genetic control system that uses a CRISPR-based approach to engineer deployable mosquitoes that can suppress populations,” said Omar Akbari, one of the study’s authors. “Males don’t transmit diseases, so the idea is that, as you release more and more sterile males, you can suppress the population without relying on harmful chemicals and insecticides.” But it’s the female population that spreads diseases, so pgSIT targets them, as well. According to the study, the CRISPR technology treatment renders female mosquitoes unable to fly or hold their wings up. It also makes them slower and more lethargic in their movements. Combined, these effects lower the chances that these female mosquitoes will mate or successfully find a blood source and attach to it to spread disease.
Lab-scale characterization and semi-field trials of Wolbachia Strain wAlbB in a Taiwan Wolbachia introgressed Ae. aegypti strain
20383W. L. Liu, H. Y. Yu, Y. X. Chen, B. Y. Chen, S. N. Leaw, C. H. Lin, M. P. Su, L. S. Tsai, Y. Chen, S. H. Shiao, Z. Y. Xi, A. C. C. Jang and C. H. Chen, PLOS Neglected Tropical Diseases, 16:24. 2022-01-11 08:53:33.
Author summaryPrior to open field release, new genetic approaches that interfere with mosquito abilities and reduce mosquito population density require progressive evaluation both in the laboratory and contained field trials. Trials in contained outdoor systems are thus an important step and allow for evaluation of the effectiveness and reliability of Wolbachia-infected Aedes aegypti (wAlbB-Tw) in settings that incorporate natural environmental variations. We describe a semi-field system designed to study the ability of wAlbB-Tw mosquitoes to suppress local mosquito populations. We provide a protocol for establishing, maintaining, and monitoring Ae. aegypti population densities inside field cages. These results pave the way for the open release of wAlbB-Tw-infected Ae. aegypti mosquitoes in the field. Dengue fever is one of the most severe viral diseases transmitted by Aedes mosquitoes, with traditional approaches of disease control proving insufficient to prevent significant disease burden. Release of Wolbachia-transinfected mosquitoes offers a promising alternative control methodologies; Wolbachia-transinfected female Aedes aegypti demonstrate reduced dengue virus transmission, whilst Wolbachia-transinfected males cause zygotic lethality when crossed with uninfected females, providing a method for suppressing mosquito populations. Although highly promising, the delicate nature of population control strategies and differences between local species populations means that controlled releases of Wolbachia-transinfected mosquitoes cannot be performed without extensive testing on specific local Ae. aegypti populations. In order to investigate the potential for using Wolbachia to suppress local Ae. aegypti populations in Taiwan, we performed lab-based and semi-field fitness trials. We first transinfected the Wolbachia strain wAlbB into a local Ae. aegypti population (wAlbB-Tw) and found no significant changes in lifespan, fecundity and fertility when compared to controls. In the laboratory, we found that as the proportion of released male mosquitoes carrying Wolbachia was increased, population suppression could reach up to 100%. Equivalent experiments in semi-field experiments found suppression rates of up to 70%. The release of different ratios of wAlbB-Tw males in the semi-field system provided an estimate of the optimal size of male releases. Our results indicate that wAlbB-Tw has significant potential for use in vector control strategies aimed at Ae. aegypti population suppression in Taiwan. Open field release trials are now necessary to confirm that wAlbB-Tw mediated suppression is feasible in natural environments.
Determinants of stakeholders’ attitudes and intentions toward supporting the use of Wolbachia-infected Aedes mosquitoes for dengue control
19744A. F. Arham, L. Amin, M. A. C. Mustapa, Z. Mahadi, M. Yaacob and M. Ibrahim, BMC Public Health, 21:2314. 2021-12-23 13:22:08.
BACKGROUND: A recent approach in controlling dengue is by using the Wolbachia-infected Aedes mosquito (WiAM). The approach has been reported to be more effective than traditional methods, such as fogging. Therefore, it is imperative to assess the factors predicting its acceptance among stakeholders before implementing this technology more widely in Malaysia. METHODS: The survey data were collected from two primary stakeholder groups using a stratified random sampling technique. The two primary stakeholder groups were scientists (n = 202) and the public (n = 197) in the Klang Valley region of Malaysia, a hot spot area known for the high rate of dengue cases. The respondents answered questions on a seven-point Likert scale survey regarding trust in key players, attitudes toward nature versus materialism, religiosity, perceived benefits, perceived risks, attitudes, and intentions. The data were analyzed using Smart Partial Least Square (SmartPLS) software (version 3.2.6) to determine the predictors influencing attitudes and intentions to support the use of WiAM technology. RESULTS: The results indicated a strong positive relationship between attitudes and intentions to support the use of WiAM (β = 0.676, p < 0.001). The most important significant predictor for attitudes was perceived benefits (β = 0.493, p < 0.001), followed by perceived risks (β = - 0.080, p = 0.048). Trust in key players, attitudes toward nature versus material, and religiosity had indirect relationships with attitudes through the perceived benefits and risks. CONCLUSIONS: The identified predictors can serve as indicators for the decision-making process regarding WiAM implementation in Malaysia and other developing countries with similar demographics and cultures.
Aedes Control Using Sterile Insect Technique (SIT) in Malaysia
19973W. A. Nazni, G.-N. Teoh, S. I. Shaikh Norman Hakimi, M. A. Muhammad Arif, M. Tanusshni, M. A. Nuradila, A. Nurfarahin Hanini, I. A. Shazia, A.-M. Tan, H. Rabizah, M. D. Ahmad Zainuri, A. Hasnor Hadi, Y.-L. Cheong, A. Norazah, H. Maiga, R. S. Lees and L. H, Genetically Modified and other Innovative Vector Control Technologies, 2021-12-21 11:41:43.
The continued occurrence of massive outbreaks of Aedes-borne viral diseases of dengue, chikungunya, Zika and yellow fever, in spite of intensive and extensive application of conventional control measures, necessitates application of new tools, such as sterile insect technique (SIT), to stem the tide. Sterile insect technique is a form of biological control method, whereby sterile male insects are released in overwhelming numbers in the wild. These sterile males compete with the wild males to mate with the wild females. The females mated with sterile males will produce sterile eggs that will not hatch. Sustained release of sterile males over a period of time will lead to suppression or elimination of the natural population. Sterility is induced by gamma ray from the radioisotope of cobalt-60 and cesium-137 or X-ray. SIT is safe, cost-effective and environmentally non-polluting, and insects are unable to develop resistance to this method. SIT has a strong track record of success in elimination of agricultural pests, and this led to increased interest in using SIT against mosquitoes of public health importance. Studies and trials against Aedes were conducted in the 1960s and, more recently, against Ae. albopictus with promising results. Attempts were also made to apply SIT for the control of Aedes in several countries. Malaysia’s first experience with SIT was in the 1990s, when the Malaysian Nuclear Agency teamed with the MARDI and local universities to sterilise an agricultural pest, the diamondback moth. To prepare for the possible threat of introducing the Old World screw worm (Chrysomya bezziana) into Australia from neighbouring countries, from 1995 to 2000, Australia and Malaysia undertook a collaborative myiasis control research project located at the Institut Haiwan, Kluang, Malaysia. The project assisted in suppression trials of the screw worm in Malaysia and supported research that developed and evaluated improved Old World screw worm suppression and eradication techniques. In 2014, in collaboration with the Malaysian Nuclear Agency, the IMR conducted preliminary studies to determine the optimum sterilising dose of gamma irradiation against Ae. aegypti. In addition, the impact of sterilisation on the biological parameters of Ae. aegypti was also determined. The most effective sterilising dose that did not adversely affect the male was determined to be 55 Gy. Subsequently, a new initiative of field release of sterile Aedes aegypti males for the control of dengue was initiated in 2019. This 2-year programme will aim to release gamma ray-sterilised Ae. aegypti males in three trial sites to reduce the natural mosquito population to a level below the threshold required for dengue transmission. To ensure public acceptance, public engagement, a prerequisite for a successful release programme, will be conducted intensively prior to the release.
Engineering RNA Interference-Based Dengue Virus Resistance in the Mosquito Vector Aedes aegypti: The Current Status and Future Directions
19969S. D. Denipitiyage, Y. I. N. S. Gunawardene, Z. Federico and R. S. Dassanayake, Genetically Modified and other Innovative Vector Control Technologies, 2021-12-21 11:32:49.
Dengue is an acute, febrile disease caused by the dengue viruses (DENV) comprising four serotypes and transmitted by the mosquito vector Ae. aegypti. DENV are single-stranded, positive-sense RNA viruses of the family Flaviviridae. Dengue is declared as a current significant challenge in the Southeast Asia, imposing growing burden on infected populations. To date, dengue control has mostly relied on vector control strategies which have largely become ineffective. There is, therefore, an urgent need for novel vector control strategies. Development of genetically modified mosquito vectors to manipulate disease-vectoring populations has gathered increased interest in recent time. RNAi-mediated viral resistance contributes to the suppression of viruses, including DENV in the mosquito vector Ae. aegypti. With recent advances in the field of molecular biology, we and other scientists are continuing to engineer genes that confer virus resistance to reduce transmission rates of DENV and introducing these genes into the mosquito genome. Even though scientists successfully generated mosquito refractory to DENV2–4, no mosquito refractory to all four serotypes has been developed to date. This limitation can be overcome by systematic analysis of the molecular mechanisms of RNAi in the mosquito vector Ae. aegypti. An enhanced understanding of RNAi function in the mosquito vector Ae. aegypti will facilitate the application of RNAi to control the transmission of the dengue disease in the future. Here, based on current understanding of the RNAi, we discuss the mechanisms of RNAi in the mosquito vector Ae. aegypti. We also provide guidelines for optimal design of RNAi experiments in Ae. aegypti with the possible risks associated with them along with proposed solutions.
Measuring Public Attitudes to Releases of Transgenic Mosquitoes for Disease Control, with Special Reference to Dengue and Malaria
19958L. A. De Las Llagas and M. S. T. Gunigundo, Genetically Modified and other Innovative Vector Control Technologies, 2021-12-21 11:10:05.
Since the advent of DDT in public health and agriculture, science leaped forward with revolutionary technology such as gene drive or editing, thus making it possible to develop alternative approaches to address vector-borne diseases. However, their utilization and sustenance in public life are dependent on public attitude, i.e., societal awareness and social acceptance. In the face of strong skepticism against genetically modified organisms in both developed and developing countries, public acceptance is therefore a requirement (Boete and Beisel 2013, and Bohannon 2002, as cited in De Souza et al. Understanding the requirements and factors necessary for the acceptance of genetically modified mosquitoes as a potential malaria control tool in Ghana: a questionnaire survey, AsPac J Biol Biotechnol 21(3):76–88, 2013).
Advances in Aedes Mosquito Vector Control Strategies Using CRISPR/Cas9
19929P. D. S. U. Wickramasinghe, G. N. Silva, Y. I. N. Silva Gunawardene and R. S. Dassanayake, Genetically Modified and other Innovative Vector Control Technologies, 2021-12-21 09:39:52.
Advancements in genetic engineering have resulted in the development of mosquitoes with impaired vector competence, thereby limiting acquisition and transmission of pathogens. The main dengue (DENV) vector, Aedes aegypti, is an invasive species that have spread unwittingly across the world as a result of human trade and travel. The Ae. aegypti mosquito species has spread across tropical and subtropical regions, with higher presence in urban regions where rapid breeding patterns have shown in artificial containers. Identification of and treating an adequate number of mosquito breeding sites as a control measure have been done for the past couple of years, and yet improvement is far from the expectations, even with well-funded and well-organized initiatives. In order to stop the pathogen transmission, genetically modified mosquitoes (GMM) needs to be created and released. Despite many Aedes-related achievements, GMM creation has been challenging. The spread of particular genetic elements that impair vector competence, trigger deleterious recessive mutations, or skew a population's sex ratio can be used to prevent the spread of vector disease, or eradicate invasive organisms in a species-specific and eco-friendly manner. In recent years, genome editing strategies have evolved to make use of a variety of nucleases, ranging from sequence-specific zinc finger nucleases to modular TALENs (transcription activator-like effector nucleases) and most recently, RNA-guided nucleases adapted from bacterial adaptive immune systems, dubbed CRISPR/Cas (clustered regularly interspaced palindromic repeats/CRISPR associated systems). By combining these methods, a new era in gene editing had emerged. Generally, both of these gene editing technologies utilize sequence-specific nucleases to generate double-stranded DNA breaks (or nicks) in the target sequence, resulting in desired DNA modifications using endogenous DNA repair mechanisms. Since cells with DNA lesions are unable to divide further, the nuclease-generated strand breaks must be rapidly repaired by the cell to maintain the viability. CRISPR/Cas has been widely accepted for use in a variety of organisms, including insect species, with only minor optimization steps needed thus far. CRISPR/Cas9 technology transformed the process of engineering nucleases capable of cleaving complex genomic sequences. A complementary guide RNA (gRNA) directs the Cas9 endonuclease's operation to the specific DNA target site, enabling the editing of virtually any DNA sequence without complex protein engineering and selection procedures. Apart from genome editing, the specificity and flexibility of the CRISPR/Cas9 method enables unprecedented rapid development of genetically modified organisms with mutation systems for disease vector insect control. The stability and expression of the gene construct generated by CRISPR/Cas9 or any other method must be addressed before GMM are released, in order to make sure that pathogen transmission and formulation are interrupted robustly and completely. Spreading foreign antipathogen genes through gene drive strategies among wild mosquito populations strengthens the case for a more streamlined approach. Major fields that must be adequately assessed include risk evaluation and management, conducting studies to ensure human and environmental protection, developing effective control strategies built on comprehensive gene-driving systems, and adequately addressing the ethical, legal, and social consequences of GMM release. Although GMM is theoretically feasible as a disease control method, field releases should be made only when strong scientific evidence of human and environmental protection and effectiveness are presented, and public acceptance is addressed appropriately. This chapter discusses the diverse technological advances in generating Ae. aegypti mosquitoes which are resistant to dengue virus (DENV) and other diseases, as well as the biosafety and risk assessment of these procedures. Additionally, the chapter outlines a convincing path forward for developing successful genetic-based DENV control strategies based on CRISPR/Cas9, which could be expanded to control other arboviruses while maintaining biosafety.
Safe Application of Genetically Modified Mosquito (GMM) to Combat Dengue and Chikungunya Depends on Socioeconomic Status and Social Acceptance in the Developing Countries: A Comprehensive Analysis
19898M. N. Islam, Genetically Modified and other Innovative Vector Control Technologies, 2021-12-21 08:16:32.
The emerging and re-emerging vector-borne diseases are a serious public health problem throughout the world. It has been observed that more than 100 countries and approximately half of the world’s population are at risk on vector-borne diseases (VBDs). The global burden of the vector-borne diseases is unacceptably high. It alludes toward their functional inappropriateness, untimeliness, and irrelevance in controlling vectors and vector-borne diseases. Modern technologies, coupled with other appropriate ones within the precincts of integrated vector management (IVM), can tide over this situation posed by conventional, mostly insecticide-based, methodologies. A lot of challenges, obstacles, and interruptive factors have warranted urgent deployment of new approaches for the control of VBDs keeping in mind the inbuilt ethical, social, and regulatory issues. Genetically modified mosquito (GMM) technology is a complex and highly sophisticated biotechnological intervention for suppression of vector populations. Wolbachia-associated sterile insect technique (SIT) has been proved highly significant and effective for replacement of mosquito populations. Adopting a highly sophisticated GMM technology to suppress or replace the mosquito populations’ density is a big question in developing countries because their priority is directed to foremost fulfill the basic human rights to sustain. Yet, notwithstanding foreseeable bottlenecks, of paramount importance is the need to deploy GMM technology with due consideration to socioeconomic factors and availability of advanced biotechnological facilities during the application of GMM in the developing countries.
Genomic insertion locus and Cas9 expression in the germline affect CRISPR/Cas9-based gene drive performance in the yellow fever mosquito Aedes aegypti
19603W. R. Reid, J. Lin, A. E. Williams, R. Juncu, K. E. Olson and A. W. E. Franz, bioRxiv, 2021.12.08.471839. 2021-12-08 18:56:04.
The yellow fever mosquito Aedes aegypti is a major vector of arthropod-borne viruses, including dengue, chikungunya, and Zika. A novel approach to mitigate arboviral infections is to generate mosquitoes refractory to infection by overexpressing antiviral effector molecules. Such an approach requires a mechanism to spread these antiviral effectors through a population, for example, by using CRISPR/Cas9-based gene drive systems. Here we report an autonomous single-component gene drive system in Ae. aegypti that is designed for persistent population replacement. Critical to the design of a single-locus autonomous gene drive is that the selected genomic locus be amenable to both gene drive and the appropriate expression of the antiviral effector. In our study, we took a reverse engineering approach to target two genomic loci ideal for the expression of antiviral effectors and further investigated the use of three promoters for Cas9 expression (nanos, β2-tubulin, or zpg) for the gene drive. We found that both promoter selection and genomic target site strongly influenced the efficiency of the drive, resulting in 100% inheritance in some crosses. We also observed the formation of inheritable gene drive blocking indels (GDBI) in the genomic locus with the highest levels of gene drive. Overall, our drive system forms a platform for the further testing of driving antipathogen effector genes through Ae. aegypti populations.Competing Interest StatementThe authors have declared no competing interest.
Towards Integrated Management of Dengue in Mumbai
19735P. N. Paradkar, P. R. Sahasrabudhe, M. Ghag Sawant, S. Mukherjee and K. R. Blasdell, Viruses, 13. 2021-12-04 13:10:23.
With increasing urbanisation, the dengue disease burden is on the rise in India, especially in large cities such as Mumbai. Current dengue surveillance in Mumbai includes municipal corporation carrying out specific activities to reduce mosquito breeding sites and the use of insecticides to suppress the adult mosquito populations. Clinical cases remain either underreported or misreported due to the restriction to government clinics, missing the large private health care sector. There is a need for an integrated approach to manage dengue outbreaks in Mumbai. There are various novel strategies available for use that can be utilised to improve disease detection, mosquito surveillance, and control of mosquito-borne diseases. These novel technologies are discussed in this manuscript. Given the complex ecosystem of mosquito-borne diseases in Mumbai, integrating data obtained from these technologies would support the ongoing mosquito control measures in Mumbai.
Wolbachia reduces virus infection in a natural population of Drosophila
19437R. Cogni, S. D. Ding, A. C. Pimentel, J. P. Day and F. M. Jiggins, Communications Biology, 4:1327. 2021-11-25 20:42:30.
Wolbachia is a maternally transmitted bacterial symbiont that is estimated to infect approximately half of arthropod species. In the laboratory it can increase the resistance of insects to viral infection, but its effect on viruses in nature is unknown. Here we report that in a natural population of Drosophila melanogaster, individuals that are infected with Wolbachia are less likely to be infected by viruses. By characterising the virome by metagenomic sequencing and then testing individual flies for infection, we found the protective effect of Wolbachia was virus-specific, with the prevalence of infection being up to 15% greater in Wolbachia-free flies. The antiviral effects of Wolbachia may contribute to its extraordinary ecological success, and in nature the symbiont may be an important component of the antiviral defences of insects.
Evaluation of Transgenic Aedes aegypti L. Strain in India: A Friendly Mosquito
19979P. B. Patil, K. K. Yadav, S. K. Dasgupta, U. B. Zehr, S. R. Barwale and B. Char, Genetically Modified and other Innovative Vector Control Technologies, 2021-11-21 11:56:31.
Aedes aegypti L. is a primary vector of dengue and is also responsible for transmission of other arboviral diseases including chikungunya, yellow fever, and Zika virus worldwide. India is attributed with as much as 34% of the global burden of dengue infection as per the recent reports. It is generally acknowledged controlling the vector population in the environment is the key to effectively curb the transmission of vector-borne diseases. Existing conventional methods for controlling the vector populations are not alone sufficient for reducing populations below disease transmission thresholds and would need integration of innovative strategies. With the advancement in modern biotechnology, scientists have been trying to explore the use of genetically engineered insects for their potential use in area-wide method for vector control. One among such strains being widely tested is OX513A Ae. aegypti strain termed as Friendly™ mosquitoes, a genetically engineered strain with a repressible dominant homozygous lethal gene construct and DsRed2 fluorescent marker gene. Male adults of OX513A strain are intended to suppress the wild population of Ae. aegypti in the released environment by population suppression strategy. The lethal gene renders mating events between OX513A males and wild-type females unsuccessful by passing a copy of gene to all the progeny of mated female adults leading to the death of the progeny during development stages in the absence of repressor antidote tetracycline. This OX513A strain was reviewed and recommended for carefully planned pilot deployment and randomized control trials with epidemiological outcomes to build evidence for routine programmatic use against Ae. aegypti-borne diseases by World Health Organization’s Vector Control Advisory Group in the year 2016. The strain is being tested globally in different countries including India for its efficacy and has been deregulated in Brazil for its use in vector control program. This chapter reviews our research investigations conducted on transgenic OX513A Ae. aegypti strain and its potential for use in dengue vector control in India.
Science Has Given Us the Power to Undermine Nature’s Deadliest Creature: Should We Use It?
19304E. Herold, leaps.org, 2021-11-16 13:32:15.
British biotech company Oxitec has engineered male mosquitoes to have a genetic "kill-switch" that could potentially crash the local population of Aedes aegypti, at least in the short-term. The modified males that are being released are intended to mate with wild females. Males don't bite; it's the female that's deadly, always seeking out blood to gorge on to help mature her eggs. After settling her filament-thin legs on her prey, she sinks a needlelike proboscis into the skin and sucks the blood until her translucent belly is bloated and glowing red. The kill-switch will ensure that the female offspring die before they reach maturity and thus, be unable to reproduce. Should a small number of them survive, they will be rendered unable to bite. The genetic modification means the proboscis, the sickle-like needle that pierces the skin, won't form properly. The idea is that the lack of females for the males to mate with, over a few generations, will collapse the local population of Aedes aegypti. The modified mosquitoes are the second genetically engineered insect to be released in the U.S. by Oxitec. The first was a modified diamondback moth, an agricultural pest that doesn't bite humans. But with the mosquitoes, there are many questions about the long-term effects on wild ecosystems, other species in the food chain, and human health. With the Keys initiative, there has been vociferous opposition from environmental groups and some local residents, but some scientists and public health experts say that genetically modified insects pose less of a risk than the diseases they carry and the powerful, indiscriminant pesticides used to combat them.
A Household-Based Survey to Understand Factors Influencing Awareness, Attitudes and Knowledge towards Wolbachia-Aedes Technology
19435L. T. Soh, Z. Ong, K. Vasquez, I. Chen, X. Li, W. Niah, C. Panchapakesan, A. Sheldenkar, S. Sim, L. C. Ng and M. O. Lwin, International Journal of Environmental Research and Public Health, 18. 2021-11-15 20:37:00.
In 2016, Singapore introduced the release of male Wolbachia-Aedes mosquitoes to complement vector control efforts and suppress Aedes aegypti mosquitoes in selected study sites. With ongoing expansion of Project Wolbachia-Singapore to cover larger areas, a household-based survey was conducted between July 2019 to February 2020 in two Project Wolbachia study sites using a structured questionnaire, to evaluate current sentiments and assess the need for enhanced public messaging and engagement. The association of factors that influence awareness, attitudes, and knowledge towards the use of Wolbachia-Aedes technology was analysed using Pearson's Chi-square test and binary logistic regression. Of 500 respondents, 74.8% were aware of Project Wolbachia-Singapore. Comparatively, the level of knowledge on Wolbachia-Aedes technology was lower, suggesting knowledge gaps that require enhanced communication and messaging to address misinformation. Longer exposure to the project predicted greater awareness, whereas higher education levels predicted higher knowledge levels. Younger age groups and higher education levels were associated with high acceptance towards the project. High levels of trust and acceptance towards the project were also observed across the population. The public's positive perception of the project is a testament to the effective public communication undertaken to date and will facilitate programme expansion.
High Temperature Cycles Result in Maternal Transmission and Dengue Infection Differences Between Wolbachia Strains in Aedes aegypti
19221M. V. Mancini, T. H. Ant, C. S. Herd, J. Martinez, S. M. Murdochy, D. D. Gingell, E. Mararo, P. C. D. Johnson and S. P. Sinkins, mBio, e0025021. 2021-11-10 21:39:39.
Environmental factors play a crucial role in the population dynamics of arthropod endosymbionts, and therefore in the deployment of Wolbachia symbionts for the control of dengue arboviruses. The potential of Wolbachia to invade, persist, and block virus transmission depends in part on its intracellular density. Several recent studies have highlighted the importance of larval rearing temperature in modulating Wolbachia densities in adults, suggesting that elevated temperatures can severely impact some strains, while having little effect on others. The effect of a replicated tropical heat cycle on Wolbachia density and levels of virus blocking was assessed using Aedes aegypti lines carrying strains wMel and wAlbB, two Wolbachia strains currently used for dengue control. Impacts on intracellular density, maternal transmission fidelity, and dengue inhibition capacity were observed for wMel. In contrast, wAlbB-carrying Ae. aegypti maintained a relatively constant intracellular density at high temperatures and conserved its capacity to inhibit dengue. Following larval heat treatment, wMel showed a degree of density recovery in aging adults, although this was compromised by elevated air temperatures. IMPORTANCE In the past decades, dengue incidence has dramatically increased all over the world. An emerging dengue control strategy utilizes Aedes aegypti mosquitoes artificially transinfected with the bacterial symbiont Wolbachia, with the ultimate aim of replacing wild mosquito populations. However, the rearing temperature of mosquito larvae is known to impact on some Wolbachia strains. In this study, we compared the effects of a temperature cycle mimicking natural breeding sites in tropical climates on two Wolbachia strains, currently used for open field trials. When choosing the Wolbachia strain to be used in a dengue control program it is important to consider the effects of environmental temperatures on invasiveness and virus inhibition. These results underline the significance of understanding the impact of environmental factors on released mosquitoes, in order to ensure the most efficient strategy for dengue control.
The drone, the tool of the future to combat its spread
19234T. Thompson, Your Decommissioning News, 2021-11-09 22:01:19.
Drones could become a promising tool in the fight against the tiger mosquito, according to a study published Tuesday by French researchers. French researchers said on Tuesday that drones could, within a few years, integrate into the arsenal of the fight against the tiger mosquito, an invasive species that appeared on mainland France about fifteen years ago, revealing the results of an experiment conducted in Montpellier. The tiger mosquito, Aedes albopictus, now detected in 65 French departments, grows at 80% in individuals, mainly in standing water in gardens. It is more harmful because it stings constantly during the day and can transmit viral diseases such as dengue, chikungunya or Zika if it has been stung by a previous patient. Therefore the first preventive measure against this insect, whose reproduction is preferred by high temperatures, is to systematically empty and overturn containers that may contain water, such as a simple ashtray. But additional methods have emerged in recent years, including the so-called “sterile insect technique” (TIS), which consists of raising male mosquitoes in laboratories, sterilizing them, and then releasing them into the field, where wild females are sterilized. which will not have offspring.
Fighting Dengue Virus with Biological Weapons
19130Z. Ebrahim, Inter Press Service, 2021-11-02 14:34:03.
For the last 11 years, he has been trying to convince both the provincial and central governments of making “billions of mosquitoes in labs”, which when released in the wild, could reduce the spread of dengue virus, but with little luck. The released genetically engineered male (only) mosquitoes, when they mate with Aedes females (also the carrier of the virus), would produce offspring that would die while still at larvae or pupae stage, explained Ali, the only Pakistani with a doctorate in genetically modified mosquitoes. In addition, genetic modifications, he said, can also shorten the life span, cause sterility and even death of the transformed Aedes species. However, those who can decide have dawdled for too long with the result that the virus has gone out of control, he remarked. He has been trying to draw attention but with little success. “They [government officials] tell me if word gets out the government was fighting the virus by letting loose even more mosquitoes, they will have to confront the wrath of the public!”
Wolbachia goes to work in the war on mosquitoes
19076S. Ong, Nature, 598:S32-s34. 2021-10-29 20:37:48.
There are two approaches to tackling dengue with Wolbachia. The first involves releasing only modified male mosquitoes. Since 2015, this strategy has been successfully adopted in Singapore and Guangzhou, China, and in parts of the United States, such as Miami, Texas and California. Because eggs produced from unmodified females that mate with modified males do not hatch, the number of mosquitoes in the community is greatly reduced. The second approach, used by some cities in Vietnam, Indonesia, Malaysia, Brazil and Australia, among others, involves releasing modified mosquitoes of both sexes. The infected females pass the bacteria to their offspring. Over time (several months to years, depending on characteristics of the release site), the modified mosquitoes replace the native population.
A decade of stability for wMel Wolbachia in natural Aedes aegypti populations
19080P. A. Ross, K. L. Robinson, Q. Yang, A. G. Callahan, T. L. Schmidt, J. K. Axford, M. P. Coquilleau, K. M. Staunton, M. Townsend, S. A. Ritchie, M.-J. Lau, X. Gu and A. A. Hoffmann, bioRxiv, 2021.10.27.466190. 2021-10-28 20:41:44.
Mosquitoes carrying Wolbachia endosymbionts are being released in many countries for arbovirus control. The wMel strain of Wolbachia blocks Aedes-borne virus transmission and can spread throughout mosquito populations by inducing cytoplasmic incompatibility. Aedes aegypti mosquitoes carrying wMel were first released into the field in Cairns, Australia, over a decade ago, and with wider releases have resulted in the near elimination of local dengue transmission. The long-term stability of Wolbachia effects is critical for ongoing disease suppression, requiring tracking of phenotypic and genomic changes in Wolbachia infections following releases. We used a combination of field surveys, phenotypic assessments, and Wolbachia genome sequencing to show that wMel has remained stable in its effects for up to a decade in Australian Ae. aegypti populations. Phenotypic comparisons of wMel-infected and uninfected mosquitoes from near-field and long-term laboratory populations suggest limited changes in the effects of wMel on mosquito fitness. Treating mosquitoes with antibiotics used to cure the wMel infection had limited effects on fitness in the next generation, supporting the use of tetracycline for generating uninfected mosquitoes without off-target effects. wMel has a temporally stable within-host density and continues to induce complete cytoplasmic incompatibility. A comparison of wMel genomes from pre-release (2010) and nine years post-release (2020) populations show few genomic differences and little divergence between release locations, consistent with the lack of phenotypic changes. These results indicate that releases of Wolbachia-infected mosquitoes for population replacement are likely to be effective for many years, but ongoing monitoring remains important to track potential evolutionary changes.Competing Interest StatementThe authors have declared no competing interest.
Novel Symbiotic Genome-Scale Model Reveals Wolbachia’s Arboviral Pathogen Blocking Mechanism in Aedes aegypti
18936N. E. Jiménez, Z. P. Gerdtzen, Á. Olivera-Nappa, J. C. Salgado and C. Conca, mBio, e0156321. 2021-10-13 20:29:16.
Arboviral diseases such as Zika and Dengue have been on the rise mainly due to climate change, and the development of new treatments and strategies to limit their spreading is needed. The use of Wolbachia as an approach for disease control has motivated new research related to the characterization of the mechanisms that underlie its pathogen-blocking properties. In this work, we propose a new approach for studying the metabolic interactions between Aedes aegypti and Wolbachia using genome-scale models, finding that pathogen blocking is mainly influenced by competition for the resources required for Wolbachia and viral replication.
Fighting the world’s most deadly animal: the mosquito
19227M. Rozenbaum, Understanding Animal Research, 2021-10-09 21:50:46.
n the first, sterile male mosquitos are mass produced and released into the wild. These sterile males mate with wild females who then lay sterile eggs which will not hatch. This approach has been shown to reduce wild populations by as much as 90% in trials with Aedes aegypt. The second approach is to introduce a gene that, if inherited, results in the death of the female, but not the male. Genetically modified males are mass produced and released. Only male offspring from matings between the modified males and wild females survive. They go on to breed, further spreading the female-killing gene and reducing the overall mosquito population. Genetically modified mosquitoes have been successfully used in parts of Brazil, the Cayman Islands, Panama, and India to control Ae. aegypti mosquitoes. Since 2019, over one billion GM mosquitoes have been released. When genetically modified mosquitoes stop being released into an area, the Ae. aegypti mosquito population slowly returns to normal levels, so control requires regular release of modified mosquitos.
Novel Sterile Insect Technology Program Results in Suppression of a Field Mosquito Population and Subsequently to Reduced Incidence of Dengue
30892Lisiane de Castro Poncio, Filipe Apolinário dos Anjos, Deborah A de Oliveira, Débora Rebechi, et al., The Journal of Infectious Diseases, 224:1005-1014. 2021-09-15 08:29:17.
There is a steady rise in the global incidence of Aedes-borne arbovirus disease. It has become urgent to develop alternative solutions for mosquito vector control. We developed a new method of sterilization of male mosquitoes with the goal to suppress a local Aedes aegypti population and to prevent the spread of dengue. Sterile male mosquitoes were produced from a locally acquired Ae. aegypti colony by using a treatment that includes double-stranded RNA and thiotepa. A field study was conducted with sterile mosquito releases being performed on a weekly basis in predefined areas. There were 2 intervention periods (INT1 and INT2), with treatment and control areas reversed between INT1 and INT2. During INT1, releases in the treated area resulted in up to 91.4% reduction of live progeny of field Ae. aegypti mosquitoes recorded over time, while the control neighborhoods (no releases of sterile male mosquitoes) remained highly infested. The successful implementations of the program during INT1 and INT2 were associated with 15.9-fold and 13.7-fold lower incidences of dengue in the treated area compared to the control areas, respectively. Our data show the success of this new sterile insect technology-based program in preventing the spread of dengue.
Assessment of fitness and vector competence of a New Caledonia wMel Aedes aegypti strain before field-release
18360N. Pocquet, O. O’Connor, H. A. Flores, J. Tutagata, M. Pol, D. J. Hooker, C. Inizan, S. Russet, J. M. Duyvestyn, E. C. Pacidônio, D. Girault, D. da Silva Gonçalves, M. Minier, F. Touzain, E. Chalus, K. Lucien, F. Cheilan, T. Derycke, S. Laumond, C. P. Sim, PLOS Neglected Tropical Diseases, 15:e0009752. 2021-09-07 14:13:26.
Dengue represents a risk for almost half of the world’s population, especially throughout the tropics. In New Caledonia, dengue outbreaks have become more frequent in the past decade along with the recent circulation of chikungunya and Zika viruses. The opportunity to use the biocontrol method involving the release of Wolbachia-infected Ae. aegypti mosquitoes has been investigated as an alternative solution to the traditional control methods, like elimination of larval habitats and pyrethroid insecticide application to kill adults, which are becoming insufficient. A local strain of Ae. aegypti carrying Wolbachia (NC-wMel) has been generated and tested to evaluate its pathogen blocking capacity for the four dengue virus serotypes as well as chikungunya and Zika viruses. The fitness of NC-wMel strain has also been assessed to estimate its ability to compete with the wild-type strain in the field. Noumea city, where a third of the population of New Caledonia resides, has been chosen as the first site to implement the method in New Caledonia. As Ae. aegypti is the only proven vector in New Caledonia, we expect a significant impact on dengue outbreaks occurring in Noumea as soon as a high frequency of NC-wMel is established in the population.
wMel Wolbachia genome remains stable after 7 years in Australian Aedes aegypti field populations
18281K. R. Dainty, J. Hawkey, L. M. Judd, E. C. Pacidônio, J. M. Duyvestyn, D. S. Gonçalves, S. Y. Lin, T. B. O'Donnell, S. L. O'Neill, C. P. Simmons, K. E. Holt and H. A. Flores, Microbial Genomics, 7. 2021-09-02 14:23:53.
Infection of wMel Wolbachia in Aedes aegypti imparts two signature features that enable its application for biocontrol of dengue. First, the susceptibility of mosquitoes to viruses such as dengue and Zika is reduced. Second, a reproductive manipulation is caused that enables wMel introgression into wild-type mosquito populations. The long-term success of this method relies, in part, on evolution of the wMel genome not compromising the critical features that make it an attractive biocontrol tool. This study compared the wMel Wolbachia genome at the time of initial releases and 1-7 years post-release in Cairns, Australia. Our results show the wMel genome remains highly conserved up to 7 years post-release in gene sequence, content, synteny and structure. This work suggests the wMel genome is stable in its new mosquito host and, therefore, provides reassurance on the potential for wMel to deliver long-term public-health impacts.
Wolbachia as translational science: controlling mosquito-borne pathogens
17799E. P. Caragata, H. L. C. Dutra, P. H. F. Sucupira, A. G. A. Ferreira and L. A. Moreira, Trends in Parasitology, 2021-07-22 20:54:55.
In this review we examine how exploiting the Wolbachia?mosquito relationship has become an increasingly popular strategy for controlling arbovirus transmission. Field deployments of Wolbachia-infected mosquitoes have led to significant decreases in dengue virus incidence via high levels of mosquito population suppression and replacement, emphasizing the success of Wolbachia approaches. Here, we examine how improved knowledge of Wolbachia?host interactions has provided key insight into the mechanisms of the essential phenotypes of pathogen blocking and cytoplasmic incompatibility. And we discuss recent studies demonstrating that extrinsic factors, such as ambient temperature, can modulate Wolbachia density and maternal transmission. Finally, we assess the prospects of using Wolbachia to control other vectors and agricultural pest species.
Yes, genetically modified mosquitoes do exist, but they don’t bite and aren’t harmful to humans
17815E. Jones and M. Chamberlin, WKYC Studios, 2021-07-19 14:35:11.
In 2021, Oxitec, a biotechnology company that develops genetically modified insects that safely and sustainably control pests that spread disease, damage crops and harm livestock across the globe, partnered with the Florida Keys Mosquito Control District (FKMCD) to evaluate the effectiveness of Oxitec mosquitoes to control the invasive, disease-spreading Aedes aegypti mosquito in the Florida Keys. Aedes aegypti mosquitoes typically live in tropical and subtropical climates, according to the CDC. The agency says Aedes aegypti mosquitoes are more likely to spread Zika, dengue, chikungunya and other viruses than other types of mosquitoes because they live near and prefer to feed on people. “One of the things that sort of works against the Aedes aegypti is that they are anthropophilic,” said Dr. Floyd Shockley, the collections manager in the Department of Entomology at the Smithsonian National Museum of Natural History. “Most of the mosquitoes that feed on humans tend to fly at night, but Aedes aegypti flies during the day. It's actually the mosquito that you usually run into when you're out hiking.” Dr. Nathan Rose, the head of Regulatory Affairs at Oxitec, tells VERIFY the company produces genetically modified male mosquitoes to target the wild Aedes aegypti female mosquitoes because they are the main vector for viral diseases.
Combating mosquito-borne diseases using genetic control technologies
17735G.-H. Wang, S. Gamez, R. R. Raban, J. M. Marshall, L. Alphey, M. Li, J. L. Rasgon and O. S. Akbari, Nature Communications, 12:4388. 2021-07-19 13:06:45.
Mosquito-borne diseases, such as dengue and malaria, pose significant global health burdens. Unfortunately, current control methods based on insecticides and environmental maintenance have fallen short of eliminating the disease burden. Scalable, deployable, genetic-based solutions are sought to reduce the transmission risk of these diseases. Pathogen-blocking Wolbachia bacteria, or genome engineering-based mosquito control strategies including gene drives have been developed to address these problems, both requiring the release of modified mosquitoes into the environment. Here, we review the latest developments, notable similarities, and critical distinctions between these promising technologies and discuss their future applications for mosquito-borne disease control.
Fighting disease: How are genetically engineered mosquitoes regulated?
17652A. Julie, Global News, 2021-07-08 19:26:36.
Mosquitoes have long been associated with the spread of diseases like malaria, dengue fever and the Zika virus. But scientists around the world have been exploring the possibility that mosquitoes could also be key to slowing the spread of disease. By genetically altering the DNA of mosquitoes, scientists hope to prevent them from passing on pathogens to humans and, therefore, control the spread of vector-borne diseases. To some, it is an exciting opportunity that could open up new possibilities in the fight against endemic diseases. But the practice has also raised questions from some in the scientific and environmental communities about the impact on local ecosystems, and the ripple effects such modifications could have on the mosquito populations themselves.
The (Losing) Battle Against Mosquitoes In Texas
17599J. Clayton, Texas Public Radio, 2021-06-26 14:13:20.
Jerry Clayton: Mosquitoes are a fact of life in Texas, and the battle against the pesky biting insects is never ending. But there are some new weapons on the horizon. Zach Adleman is an associate professor of entomology at Texas A&M University. He joins us today. Thanks for being here, Zach.
A wAlbB Wolbachia< transinfection displays stable phenotypic effects across divergent Aedes aegypti mosquito backgrounds
17592P. A. Ross, X. Gu, K. L. Robinson, Q. Yang, E. Cottingham, Y. Zhang, H. L. Yeap, X. Xu, N. M. Endersby-Harshman and A. A. Hoffmann, bioRxiv, 2021.06.25.450002. 2021-06-26 14:00:37.
Aedes mosquitoes harboring intracellular Wolbachia bacteria are being released in arbovirus and mosquito control programs. With releases taking place around the world, understanding the contribution of host variation to Wolbachia phenotype is crucial. We generated a Wolbachia transinfection (wAlbBQ) in Aedes aegypti and performed backcrossing to introduce the infection into Australian or Malaysian nuclear backgrounds. Whole Wolbachia genome sequencing shows that the wAlbBQ transinfection is near-identical to the reference wAlbB genome, suggesting few changes since the infection was first introduced to Ae. aegypti over 15 years ago. However, these sequences were distinct from other available wAlbB genome sequences, highlighting the potential diversity of wAlbB in natural Ae. albopictus populations. Phenotypic comparisons demonstrate effects of wAlbB infection on egg hatch and nuclear background on fecundity and body size, but no interactions between wAlbB infection and nuclear background for any trait. The wAlbB infection was stable at high temperatures and showed perfect maternal transmission and cytoplasmic incompatibility regardless of host background. Our results demonstrate the stability of wAlbB across host backgrounds and point to its long-term effectiveness for controlling arbovirus transmission and mosquito populations.Competing Interest StatementThe authors have declared no competing interest.
Manipulated Mosquitoes Cut Dengue by 77%
17513T. Hayes, Healthcare Packaging, 2021-06-22 14:34:21.
Dengue, a mosquito-borne viral disease, wasn’t that common 50 years ago. In fact, only nine countries had severe outbreaks. But since then, it’s been on a steady incline to the point that there are now 400 million infections a year that contribute to 22,000 deaths. Thankfully, we have the World Mosquito Programme, a group that’s fighting the tropical mosquito disease head-on with genetically modified mosquitoes. The insects are infected with Wolbachia, a bacteria that inhibits viruses’ ability to live inside the insects, and also controls reproduction so that offspring are also infected with the bacteria. The result is a new population of insects that can’t transmit viruses like dengue, yellow fever and Zika. The study in Indonesia included 8,000 people, and concluded with protective efficacy of 77.1%.
Dengue fever: Upstaged but not outmatched by COVID-19
17490C. E. Baclig, INQUIRER.NET, 2021-06-17 15:17:30.
Science has made gains in the war on dengue and other diseases that mosquitoes carry, like malaria.One of these is the World Mosquito Program (WMP), a non-profit initiative that aims to protect the global community from mosquito-borne viral diseases, by deploying a natural bacteria, called Wolbachia. On its website, WMP said its scientists had discovered that Aedis aegypti mosquitoes carry Wolbachia, a bacteria which competes with viruses like dengue, zika, chikungunya, and the virus that causes yellow fever. Wolbachia, WMP said, was found to make it difficult for viruses to reproduce inside mosquitoes. Mosquitoes carrying Wolbachia, WPS said, “are much less likely to spread viruses from person to person.” Wolbachia is found in 60 percent of insects but is not normally carried by Aedis aegypti mosquitoes. So scientists injected the bacteria into mosquito eggs. Once these hatches and send off grown mosquitoes, they are released to breed with local mosquito populations.
Genetically Modified Mosquitoes; ‘Truth Like Oil’ Novel
17487Here and Now, WBUR, 2021-06-16 15:10:42.
Florida Keys officials are working on a unique experiment: hatching thousands of genetically modified mosquitos and releasing them. Andrea Leal of the Florida Keys Mosquito Control District explains.
Dengue Infections Can Be Sharply Reduced With Wolbachia Bacteria
17453J. Stone, Medscape, 2021-06-14 17:25:12.
A modestly titled new study released in the New England Journal of Medicine belies the extraordinary 77% protective efficacy reported for preventing dengue infections with Wolbachia-infected Aedes aegypti mosquitoes. A cluster-randomized clinical trial, the AWED ("Applying Wolbachia to Eliminate Dengue") study was conducted in Yogyakarta, Indonesia and led by professors Adi Utarini, MD, PhD, of Gadjah Mada University and Cameron Simmons, PhD, the World Mosquito Program's Oceana director, in partnership with the Tahija Foundation and Monash University.
Making mosquitoes to fight mosquitoes to prevent dengue
17484A. George, Times of India, 2021-06-14 15:04:01.
In 2017, Delhi Chief Minister Arvind Kejriwal tweeted that the national capitl needed to be made mosquito-free. The same year, his Kerala counterpart, Pinaray Vijayan, called a three-day state-wide cleanliness drive as hospitals filled with genue patients.
Using Wolbachia to Eliminate Dengue: Will the Virus Fight Back?
18270M. Edenborough Kathryn, A. Flores Heather, P. Simmons Cameron, E. Fraser Johanna and C. Pierson Ted, Journal of Virology, 95:e02203-20. 2021-06-10 14:06:11.
Recent fieldtrials havedemonstratedthatdengue incidence can besubstantially reduced by introgressing strains of the endosymbiotic bacterium Wolbachia into Aedes aegypti mosquito populations. This strategy relies on Wolbachia reducing the susceptibility of Ae. aegypti to disseminated infection by positive-sense RNA viruses like dengue. However, RNA viruses are well known to adapt to antiviral pressures. Here, we review the viral infection stages where selection for Wolbachia-resistant virus variants could occur. We also consider the genetic constraints imposed on viruses that alternate between vertebrate and invertebrate hosts, and the likely selection pressures to which dengue virus might adapt in order to be effectively transmitted by Ae. aegypti that carry Wolbachia. While there are hurdles to dengue viruses developing resistance to Wolbachia, we suggest that long-term surveillance for resistant viruses should be an integral component of Wolbachia-introgression biocontrol programs.
Dengue Fever Cut Down by 77% With Groundbreaking Bacteria-Armed Mosquitoes
17322M. Davis, The Science Times, 2021-06-10 12:02:22.
Scientists found that dengue fever cases have decreased by 77% in a groundbreaking trial that took place in Yogyakarta City, Indonesia. They used Wolbachia-infected mosquitoes that reduced their ability to spread the dengue fever. The team at the World Mosquito Program said that this could be a solution to dengue fever that is prevalent around the world. Dr. Katie Anders, one of the researchers, described the trial of using Wolbachia-infected mosquitoes in Indonesia as a "naturally miraculous" solution. Wolbachia is a virus-fighting bacteria that has been approved since 2017 by the Environmental Protection Agency (EPA) for use in the United States. Other interventions, like genetically modified mosquitoes, are also used to combat dengue fever and other diseases caused by mosquitoes. According to BBC News, Wolbachia does not harm the mosquito, but it will only be stored in the same parts of the mosquito's body where the dengue virus is kept. It competes for the resources, preventing the dengue virus to replicate, and therefore the mosquito is less likely to cause the infection when it bites. Moreover, Wolbachia bacteria can also manipulate and alter the fertility of their hosts. They make sure that they are passed on to the next generation of mosquitoes, which means they are established and should stick around for a long time to continue their protective abilities against dengue fever.
Mosquito ‘bacteria hack’ nearly eliminates dengue fever and could save millions of lives
17316A. Wilkins, METRO, 2021-06-10 11:50:12.
Mosquitoes infected with a ‘miraculous’ bacteria have been shown to reduce dengue fever cases by 77%, in a groundbreaking new study. Scientists released mosquitoes infected with ‘Wolbachia’ bacteria into the Indonesian city of Yogyakarta – but only in certain zones. In the zones where the modified mosquitoes had been released, cases of dengue fell by 77% and hospitalisations dropped by 86%. The results of the study, carried out by the World Mosquito Programme (WMP), were ‘better than we could have hoped for’, according to researcher Dr. Katie Anders. Cases of dengue fever, a virus that can cause muscle and bone pain, and death, have risen rapidly in the past decades – there are an estimated 400 million cases a year. The Wolbachia bacteria used in the trial were chosen because it hides in the same parts of a mosquito’s body that dengue virus hides in. A bacteria that is benign to humans, the Wolbachia then competes for resources with the dengue virus, which makes it less likely for the mosquito to cause a dengue infection when it bites a human.
‘Miraculous’ mosquito hack cuts dengue by 77%
17311J. Gallagher, BBC, 2021-06-10 11:38:57.
Dengue fever cases have been cut by 77% in a "groundbreaking" trial that manipulates the mosquitoes that spread it, say scientists. They used mosquitoes infected with "miraculous" bacteria that reduce the insect's ability to spread dengue. The trial took place in Yogyakarta city, Indonesia, and is being expanded in the hope of eradicating the virus. The World Mosquito Programme team says it could be a solution to a virus that has gone around the world. Few people had heard of dengue 50 years ago, but it has been a relentless slow-burning pandemic and cases have increased dramatically. In 1970, only nine countries had faced severe dengue outbreaks, now there are up to 400 million infections a year. Dengue is commonly known as "break-bone fever" because it causes severe pain in muscles and bones and explosive outbreaks can overwhelm hospitals.
Modified mosquitoes reduce dengue cases by 77% in Indonesia experiment
17309M. Fox, CNN, 2021-06-10 11:32:59.
An experiment to infect mosquitoes with bacteria that stop them from transmitting viruses appears to have helped reduced the spread of deadly dengue virus in Indonesia, researchers reported Wednesday. The modified mosquitoes thrived for three years, and cases of dengue were reduced by 77% in areas where they were introduced, the researchers reported in the New England Journal of Medicine. The mosquitoes are infected with bacteria called Wolbachia, which not only interfere with the ability of viruses to live in the bodies of the insects, but which also control reproduction so that the mosquitoes only have Wolbachia-infected offspring. The result is a growing population of insects that don't pass on viruses such as dengue, yellow fever and Zika. The study involved more than 8,000 people, about half of whom lived in areas where the modified Aedes aegypti mosquitoes had been living and breeding.
Efficacy of Wolbachia-Infected Mosquito Deployments for the Control of Dengue
17300A. Utarini, C. Indriani, R. A. Ahmad, W. Tantowijoyo, E. Arguni, M. R. Ansari, E. Supriyati, D. S. Wardana, Y. Meitika, I. Ernesia, I. Nurhayati, E. Prabowo, B. Andari, B. R. Green, L. Hodgson, Z. Cutcher, E. Rancès, P. A. Ryan, S. L. O’Neill, S. M. Dufau, New England Journal of Medicine, 384:2177-2186. 2021-06-10 11:05:41.
BACKGROUND Aedes aegypti mosquitoes infected with the wMel strain of Wolbachia pipientis are less susceptible than wild-type A. aegypti to dengue virus infection. METHODS We conducted a cluster-randomized trial involving releases of wMel-infected A. aegypti mosquitoes for the control of dengue in Yogyakarta, Indonesia. We randomly assigned 12 geographic clusters to receive deployments of wMel-infected A. aegypti (intervention clusters) and 12 clusters to receive no deployments (control clusters). All clusters practiced local mosquito-control measures as usual. A test-negative design was used to assess the efficacy of the intervention. Patients with acute undifferentiated fever who presented to local primary care clinics and were 3 to 45 years of age were recruited. Laboratory testing was used to identify participants who had virologically confirmed dengue (VCD) and those who were test-negative controls. The primary end point was symptomatic VCD of any severity caused by any dengue virus serotype. RESULTS After successful introgression of wMel into the intervention clusters, 8144 participants were enrolled; 3721 lived in intervention clusters, and 4423 lived in control clusters. In the intention-to-treat analysis, VCD occurred in 67 of 2905 participants (2.3%) in the intervention clusters and in 318 of 3401 (9.4%) in the control clusters (aggregate odds ratio for VCD, 0.23; 95% confidence interval [CI], 0.15 to 0.35; P=0.004). The protective efficacy of the intervention was 77.1% (95% CI, 65.3 to 84.9) and was similar against the four dengue virus serotypes. The incidence of hospitalization for VCD was lower among participants who lived in intervention clusters (13 of 2905 participants [0.4%]) than among those who lived in control clusters (102 of 3401 [3.0%]) (protective efficacy, 86.2%; 95% CI, 66.2 to 94.3).
A Pivotal Mosquito Experiment Could Not Have Gone Better
17294E. Yong, The Atlantic, 2021-06-10 10:50:58.
The World Mosquito Program (WMP), a nonprofit that pioneered this technique, had run small pilot studies in Australia that suggested it could work. Utarini, who co-leads WMP Yogyakarta, has now shown conclusively that it does. Her team released Wolbachia-carrying mosquitoes in parts of Yogyakarta as part of a randomized controlled trial. The results, which were unveiled last year and have now been published, showed that Wolbachia rapidly spread among the local mosquitoes, and reduced the incidence of dengue by 77 percent. “That provides the gold standard of evidence that Wolbachia is a highly effective intervention against dengue,” says Oliver Brady, a dengue expert at the London School of Hygiene and Tropical Medicine, who was not involved in the study. “It has the potential to revolutionize mosquito control.” The trial’s results were so encouraging that the researchers have since released Wolbachia-carrying mosquitoes over all of central Yogyakarta—a 32-square-kilometer zone that’s home to more than 400,000 people. They’re now expanding into the densest surrounding provinces, aiming to protect 4 million people by the end of 2022. If they succeed, they should be able to prevent more than 10,000 dengue infections every year, Katherine Anders of the WMP told me. And the team is optimistic enough that it’s daring to think about an even grander goal: eliminating dengue from the city altogether.
Mosquitoes armed with virus-fighting bacteria sharply curb dengue infections, hospitalizations
17319K. Servick, Science, 2021-06-09 11:55:26.
A strategy for fighting dengue fever with bacteria-armed mosquitoes has passed its most rigorous test yet: a large, randomized, controlled trial. Researchers reported today dramatic reductions in rates of dengue infection and hospitalization in areas of an Indonesian city where the disease-fighting mosquitoes were released. The team expects the World Health Organization (WHO) to formally recommend the approach for broader use. The findings are a “breakthrough” that brings the approach “much closer to … being an official strategy to control dengue,” says Ewa Chrostek, an infection biologist at the University of Liverpool who was not involved with the work. WHO estimates there are 100 million to 400 million infections per year with dengue, which can cause high fever and severe joint pain. The bacterium Wolbachia pipientis naturally inhabits many insects, though not Aedes aegypti mosquitoes, the main transmitter of dengue virus. In A. aegypti cells, the bacterium can block viruses, including dengue, from replicating, making the insects less likely to spread disease when they bite humans. That has made the microbe a promising strategy for fighting dengue. In tropical regions, where mosquito-borne viruses are common, other strategies such as insecticides have failed to fully control the disease.
Study demonstrates ‘exciting potential’ of Wolbachia-infected mosquitoes to control dengue
17313G. Gallagher, Healio, 2021-06-09 11:43:08.
The release of Wolbachia-infected mosquitoes led to a 77% reduction in the incidence of symptomatic dengue in an Indonesian city, according to researchers, who said the same approach could be used to fight other mosquito-borne diseases. The study tested a strain of Wolbachia pipientis called wMel that makes Aedes aegypti mosquitoes less susceptible to dengue virus infection. Wolbachia pipientis occurs naturally in many insects but not A. aegypti, the primary vector of dengue, according to Adi Utarini, PhD, MPH, MSc, and colleagues from the nonprofit World Mosquito Program, which has been releasing Wolbachia-infected mosquitoes in the wild since 2011. A study in Indonesia demonstrated the potential of a natural intervention to significantly reduce the incidence of dengue, the world’s most prevalent mosquito-borne disease. “Wolbachia facilitates its own population introgression by manipulating reproductive outcomes between wild-type and Wolbachia-infected mosquitoes: the only viable mating outcomes are those in which the progeny are infected with Wolbachia,” they wrote in the new report, which was published Wednesday in The New England Journal of Medicine.
Bill Gates Releasing Genetically Modified Mosquitoes in Florida? Here’s the Whole Story
17558M. Dapcevich, Snopes, 2021-06-03 14:44:33.
Bill Gates is not himself releasing mosquitoes into the wild. However, the Bill and Melinda Gates Foundation did award grants that funded biotech company Oxitec's work to develop genetically modified mosquitoes that may help reduce the spread of malaria and other mosquito-borne diseases. In April 2021, it was announced that approximately 150,000 mosquitoes would be released across six locations in Florida. Several state and federal agencies have been involved in the approval of this project. A multi-year research project to genetically modify Aedes aegypti, a mosquito species that is known to carry and transmit infectious diseases to humans, was slated to move from the lab to the fields of Texas and Florida in mid-2021. Under the project, thousands of A. aegypti were altered to make their reproduction more difficult, thus slowing and eventually preventing the spread of mosquito-borne illnesses like Zika, and dengue fever. But when the internet caught wind that Bill Gates may have been behind the project, posts circulated on social media that questioned the real motivation behind the project.
Mutant mosquitoes carrying ‘death gene’ released as ‘bio-engineered’ insects terrify
17185J. Caven, Daily Star, 2021-06-02 20:16:02.
Mutant mosquitoes which carry a ‘death gene’ have been released into the skies in a bid to curb diseases from spreading to humans. Tens of thousands of genetically modified male insects will mate with female Aedes aegypti mosquitoes, which transmit illnesses, in Florida Keys, US. Although the males don’t bite, they carry a gene which passes on and kills female offspring in the early larval stages. The pilot project aims to wipe out a generation of potential disease-carriers. Scientists say usual methods to stop the spread of disease from mosquitoes are becoming less effective due to resistance. But critics have slammed the programme and say they are being used as “guinea pigs in a sci-fi experiment”, the Times reported.
‘Death gene’ in genetically modified male mosquitoes
17181J. Goddard, The Times, 2021-06-02 20:10:43.
Tens of thousands of bio-engineered mosquitoes have taken flight in the Florida Keys under a pilot project that aims to breed insects programmed with a “death switch”. Genetically modified males produced by Oxitec — a British-founded biotechnology company — have begun mating with local populations of invasive Aedes aegypti mosquitoes, whose female progeny are programmed to die before they mature, wiping out a generation of potential disease-carriers. “Mosquito-borne disease is a very real issue and conventional controls are losing their effectiveness,” said Dr Nathan Rose, head of regulatory affairs at Oxitec in Milton Park, Oxfordshire.
Improving mosquito control strategies with population genomics
18781T. L. Schmidt, N. M. Endersby-Harshman and A. A. Hoffmann, Trends in Parasitology, 37:907-921. 2021-05-29 12:41:38.
Mosquito control strategies increasingly apply knowledge from population genomics research. This review highlights recent applications to three research domains: mosquito invasions, insecticide resistance evolution, and rear and release programs. Current research trends follow developments in reference assemblies, either as improvements to existing assemblies (particularly Aedes) or assemblies for new taxa (particularly Anopheles). With improved assemblies, studies of invasive and rear and release target populations are better able to incorporate adaptive as well as demographic hypotheses. New reference assemblies are aiding comparisons of insecticide resistance across sister taxa while helping resolve taxon boundaries amidst frequent introgression. Anopheles gene drive deployments and improved Aedes genome assemblies should lead to a convergence in research aims for Anopheles and Aedes in the coming years.
Mosquitoes are deadly pests, genetically-modified mosquitoes could help stop disease
17127T. Browne, ClickOrlando, 2021-05-27 19:04:12.
Hearing the words “genetically modified mosquitoes” can sound like the plot for a science-fiction movie but Meredith Fenson, a native Floridian turned biological pest control specialist says, “mosquitoes are the world’s deadliest animal by far” and a study happening right now in the Florida Keys could help change the tide. Fenson works as the head of global public affairs for Oxitec and sat down with News 6 anchors Matt Austin and Ginger Gadsden on Florida’s Fourth Estate podcast to talk about how genetically modified mosquitoes work, concerns surrounding their release and Oxitec’s plans to release more in the future. Aedes Aegypti, the yellow fever mosquito, only makes up about 4% of the population in the Florida Keys but Fenson says they are responsible for virtually all the diseases spread from mosquitoes to humans. She says this includes Zika, dengue fever and Chikungunya.
Florida Environmental Group Says GMO Mosquitoes Fall Short on Scientific Rigor
17079C. Drukier, NTD, 2021-05-20 15:01:00.
America’s first genetically modified mosquitoes are now buzzing around six locations in the Florida Keys as part of a pilot project. Developed by UK biotech company Oxitec, the bugs are designed to kill off the wild population of Aedes aegypti mosquitoes that carry diseases like Dengue fever, yellow fever, and the Zika virus. Some people who live in the Keys aren’t happy about being part of a science experiment. Barry Wray, executive director of the Florida Keys Environmental Coalition explains why his organization has been fighting the GMO bugs for the last decade.
Genetically Modified Mosquitoes Take Flight to Fight Invasive Species in Florid
17073T. Machemer, Smithosonian Magazine, 2021-05-17 14:46:06.
In late April, the biotechnology company Oxitec placed blue-and-white hexagonal boxes on the properties of six private volunteers around the Florida Keys. After pouring in water, the genetically modified mosquito eggs inside activated and hatched. Now the first larvae have developed into full-grown male mosquitoes and taken flight, Susan Millis reports for Science News. About 12,000 of Oxitec’s male mosquitoes will fly out of the boxes each week for the next 12 weeks. Over several mosquito generations, Oxitec’s genetically modified Aedes aegypti could reduce the population of female mosquitoes—which bite and spread disease—and then lower the entire population in the Florida Keys in turn. The current trial marks the first time that genetically modified mosquitoes have been released to fly freely in the United States.
Genetically modified mosquitoes may help scientists swat dreaded midge
17057W. Jean, The Times, 2021-05-16 13:41:37.
Scotland’s bloodthirsty midges may finally meet their match thanks to revolutionary genetic manipulation techniques that could stop the pesky insects biting chunks out of the tourist industry. News that a British biotechnology company has created genetically modified non-biting mosquitoes in Florida to help curb dengue and yellow fever, and ultimately malaria, may give hope in the fight against the annual Scottish scourge. Oxford-based Oxitec and its American partners recently released genetically modified male mosquito larvae into the Florida Keys to control the wild, disease-carrying mosquito population rather than use pesticides. While midges share some characteristics with mosquitoes, Dr Simon Carpenter, a Pirbright Institute entomologist who was part of the team that built the first complete genome of the Highland biting midge, said the gene-editing process
First Genetically Modified Mosquitoes Released in U.S. Are Hatching Now
17046D. Coffey, Scientific American, 2021-05-14 11:50:11.
This week, mosquito eggs placed in the Florida Keys are expected to hatch tens of thousands of genetically modified mosquitoes, a result of the first U.S. release of such insects in the wild. A biotechnology firm called Oxitec delivered the eggs in late April as part of a federally approved experiment to study the use of genetic engineering—rather than insecticides—to control disease-carrying mosquito populations. The move targets an invasive species, called Aedes aegypti, that carries Zika, dengue, chikungunya, yellow fever and other potentially deadly diseases, some of which are on the rise in Florida. The experiment relies on a genetic alteration that will be lethal to a large number of future offspring. In this case, male mosquitoes have been modified to carry a gene that makes their female progeny dependent on the antibiotic tetracycline—and thus fated to die in the wild. As the mating cycle repeats over generations, female numbers are depleted, and the population is suppressed. The modified insects eventually die off, making this approach self-limiting. Oxitec overcame significant regulatory hurdles before getting the go-ahead from the U.S. Food and Drug Administration in 2016 and then the Environmental Protection Agency in 2020. If the current pilot effort is successful, the firm is set to release as many as 20 million more males in the prime of Florida’s mosquito season later this year. The results of the experiment could ultimately help address concerns about releasing genetically modified organisms into the wild.
In a World-First, Genetically Modified Mosquitoes Are Hatching in the US
17044B. Bergan, INTERSTING ENGINEERING, 2021-05-14 11:44:58.
Mosquito eggs placed in the Florida Keys are about to hatch tens of thousands of genetically altered mosquitos, the first such release of "synthetic" insects in the world, according to an initial report from Scientific American. Pilot program for genetically modified mosquitoes could see millions more released this year. The biotechnology firm called Oxitec delivered the modified mosquito eggs late in April as part of a federally-endorsed experiment to study the use of genetic engineering, as opposed to insecticides, to control the populations of illness-spreading mosquitoes. This project targets one specific species of mosquito called Aedes aegypti, known to carry Zika, chikungunya, yellow fever, dengue, and other possibly deadly diseases. And some of these diseases have been on the rise in Florida. The new genetic contribution given to the mosquitoes will be deadly to many future offspring, with males altered to carry a gene causing female offspring to become dependent on the antibiotic called tetracycline — which is a death sentence for the female mosquitoes. After several generations, there won't be enough female mosquitoes of the species to maintain population numbers, putting a ceiling on them. But this is a temporary measure, since the genetically modified male mosquitoes will eventually all die.
The U.S.’s first open-air genetically modified mosquitoes have taken flight
17041S. Milius, Science News, 2021-05-14 11:35:37.
The first genetically modified mosquitoes that will be allowed to fly free outdoors in the United States have started reaching the age for mating in the Florida Keys. In a test of the biotech company Oxitec’s GM male mosquitoes for pest control, these Aedes aegypti started growing from tiny eggs set out in toaster-sized, hexagonal boxes on suburban private properties in late April. On May 12, experiment monitors confirmed that males had matured enough to start flying off on their own to court American female mosquitoes. This short-term Florida experiment marks the first outdoor test in the United States of a strain of GM male mosquitoes as a highly targeted pest control strategy. This strain is engineered to shrink local populations of Ae. aegypti, a mosquito species that spreads dengue and Zika (SN: 7/29/16). That could start happening now that the GM mosquitoes have reached mating age because their genetics makes them such terrible choices as dads.
Use of genetically modifed mosquitoes to minimize the burden of diseases casused by mosquitoes in South Texas.
17016MDN Staff, MegaDoctor News, 2021-05-11 13:00:04.
Of the many species of mosquitoes, female Aedes aegypti is the primary vector that is responsible for transmission of several diseases and has been most extensively studied. The efforts of the World Health Organization and the Center for Disease Control and Prevention to prevent and/or control mosquito-borne illness have yielded success, but it remains a serious global challenge. More recently, several approaches to create transgenic mosquitoes with the ultimate objective of preventing and/or controlling mosquito-borne illness have undergone field studies. Infecting mosquitoes with different strains of Wolbachia resulted in the reduction of egg laying rates, transmission ability and shorter lifespan. Similarly, using genetic technology, a self-limiting strain of male mosquitoes (OX513A) when released in the field have shown an 81%-95% suppression of population of this strain as compared to adjacent no-release control field. These encouraging results prompted the issuance of authorization by the U.S. Environmental Protection Agency for the use of second generation genetically modified mosquitoes (OX5034) in Florida and Texas” said Sohail Rao, MD, MA, DPhil, President and Chief Executive Officer, DHR Health Institute for Research & Development. As the first-ever use of genetically modified mosquitoes in the United States, over 750 million OX5034 will be ultimately released in the Florida Keys an area devastated by mosquito-borne illnesses
Monster Mosquito–Why the Technology of Genetically Modified Mosquitoes is Dangerous and Should Be Stopped Worldwide
17001B. Dogra, counter currents, 2021-05-10 15:32:17.
After sparking controversy in other countries including India, the technology of genetically engineered mosquitoes is now leading to widespread protests in Florida USA. Here the biotechnology giant company Oxitec in collaboration with local officialdom is moving ahead with a pilot project to release millions of genetically engineered mosquitoes in Monroe County over a period of two years or so. The stated aim is to control the population of Aedes aegypti, a species that can carry both the dengue and the yellow fever virus. The idea is for genetically altered male, non-biting mosquitoes to mate with local , biting females , producing offspring that die at larval stage. Pointing out the inherent dangers of such technologies a spokesperson of Florida Key Environmental Coalition said that everyone should be writing to the White House to stop the release, at least until regulations to protect people are in place. Friends of the Earth has commented—scientists have raised concerns that genetically engineered mosquitoes could create hybrid wild mosquitoes which could worsen the spread of mosquito borne diseases and could be more resistant to insecticides than the original wild mosquitoes.
Florida releases genetically modified mosquitoes in hopes to reduce spread of disease
17011A. Fahim, Reuters, 2021-05-10 12:50:27.
Genetically modified mosquitoes have been released for the first time in the United States, taking flight in the Florida Keys in a pilot program intended to reduce the spread of deadly diseases such as dengue, yellow fever and the Zika virus.After an odyssey spanning more than a decade to secure regulatory approval, British-based biotechnology firm Oxitec, along with the Florida Keys Mosquito Control District (FKMCD)launched the project in hope of reducing the Aedes aegypti species that spread the diseases.While Oxitec and local authorities have high hopes for the program, local residents and environmental groups worry that not enough is known about the long-term effects of the new technology.Nevertheless, the Environmental Protection Agency granted an experimental use permit (EUP) to Oxitecon May 1.A half-dozen boxes containing the OX5034 mosquito created by Oxitec have been deployed in the Florida Keys, an archipelago stretching 120 miles (195 km) off the southern tip of the state.Only female Aedes aegypti bite and spread disease, so Oxitec has created males that pass on a gene that kills female offspring before they mature. Their male offspring then continue mating and passing on the altered gene.
Why Florida is releasing genetically modified mosquitoes
16999M. Murphy, The Telegraph, 2021-05-09 15:19:45.
The thousands of lab-grown mosquitoes hatching in humid gardens across Florida’s tropical Key West next week will be blissfully ignorant of the controversy they have caused. Billboards have already begun appearing near busy motorways in protest of their arrival, with one splashed with the words “risky, unnecessary, unwanted” aside a giant picture of the blood-thirsty insect. “The word ‘genetically modified’ scares people,” says Douglas Mader, a local vet and newspaper columnist living in the Lower Keys. “They think oh my god, they’re releasing genetically modified organisms (GMOs) and they are going to bite me and I’m going to turn into a zombie”. The creatures are the creation of Oxitec, a Bill Gates-backed biotechnology company based in Abingdon, Oxfordshire. Grey Frandsen, its chief executive, and around 20 scientists at Oxitec’s labs, have made it their mission to stop the spread of diseases such as dengue, Zika and malaria by controlling mosquitoes’ reproduction.
Genetically Modified Mosquitoes Have Come to the U.S. Will They Work?
16996A. de la Garza, TIME, 2021-05-09 15:13:05.
“Our Mosquito Project Takes Flight,” reads a baby-blue billboard off US-1 in the Florida Keys, alongside an image of an insect tracing a path in the shape of a heart. Sponsored by the local mosquito control board and U.K.-based biotech firm Oxitec, the ad promotes a contentious plan to release millions of genetically modified Aedes aegypti mosquitoes here to test a new method of bioengineered pest control. It’s the first-ever such experiment in the United States, and one that has turned this chain of sun-soaked island communities into a battleground over scientific truth, government authority, and humanity’s right to modify nature. Even this bit of roadside signage is contested. Four months ago, the billboard carried a different ad, paid for by the Coalition Against GMO Mosquitoes, an organization with the mission of stopping releases of the genetically modified insects in the U.S., “WARNING!!!,” it read then, “GENETICALLY MODIFIED MOSQUITOES TO BE RELEASED IN THE KEYS!!” That release began in late April, when, after a decade of planning, regulatory review and debate, Oxitec workers and local mosquito control personnel added water to a dozen plastic boxes containing the company’s “Friendly™” mosquito eggs in six locations around the Keys, triggering their hatching process. Oxitec’s Aedes aegypti mosquitoes—which the U.S. Environmental Protection Agency (EPA) approved for use last year—are genetically modified to include a “self-limiting” gene that produces a fatal protein. The mosquitoes are raised in a laboratory in the presence of tetracycline, an antibiotic that prevents the added gene from activating. The mosquitoes’ eggs are then left to hatch in the wild, without the antibiotic. The gene kills immature egg-laying females—the only ones that bite—but the males reach maturity, mate with wild females, and pass on their faulty gene. Then their female progeny die, causing the bloodsuckers’ population to crash.
Bill Gates finances the creation of transgenic mosquitoes
16992Explica.co, explica, 2021-05-07 15:03:11.
Male mosquitoes (they do not bite. They feed on nectar, not blood) from Oxitec will emerge from release boxes placed in six locations in the Florida Keys to mate with local female mosquitoes (they do bite. They do feed on blood). The female offspring from these encounters cannot survive, and the Aedes aegypti population will be controlled in this way.. The Aedes aegypti mosquito makes up about four percent of the mosquito population in the Keys. The project has the approval of the Environmental Protection Agency (EPA) and the Florida Department of Agriculture and Consumer Services (FDACS) and the collaboration of the Florida Keys Mosquito Control District (FKMCD). In 2021, the United States expects the release of 750 million transgenic mosquitoes. “An important part of the FKMCD’s mission is to protect the residents of the Florida Keys from the disease-transmitting mosquito, Aedes aegypti. As we are seeing the development of resistance to some of our current control methods, we need new tools to fight this mosquito. And given the unique ecosystem we live in, those tools must be safe, environmentally friendly and specific. That’s why we collaborate with Oxitec on this project. With the full approval of the US EPA and from the Florida Department of Agriculture and Consumer Services, and with the support of the US Centers for Disease Control and an independent advisory board, we are pleased to announce that this project will be underway soon, ”says Andrea Leal, executive director of the FKMCD.
Genetically Modified Mosquitoes Released In US For First Time To Combat Disease
16985J. Van Zijl, IFL Science, 2021-05-06 16:11:16.
A landmark project, spearheaded by the biotechnology company, Oxitec, has released genetically modified mosquitos in the Florida Keys. This marks the first time that genetically modified mosquitos have been released into the wild in the US. The reason: to combat the Aedes aegypti mosquito species responsible for spreading mosquito-borne diseases such as dengue and Zika in the region. Aedes aegypti only accounts for about 4 percent of the total mosquito population in Florida keys – however, it is responsible for almost all mosquito-borne diseases to humans. Current methods to control the species, such as spraying or fogging chemical insecticides, have failed due to the species becoming resistant. So an alternative solution was needed.
Genetically Modified Mosquitoes Released In Florida ‘Jurassic Park Experiment’
16978D. Richardson, UNILAD, 2021-05-06 15:58:18.
Mosquitos are not only annoying but they can carry disease in their bites. In response to this, a company called Oxitec has genetically modified male mosquitos to pass on a killswitch to females. It is hoped that these genetically modified pests will help stop the transmission of deadly diseases, including yellow fever, dengue and Zika virus. The Florida Keys project, which was greenlit by the US Environment Protection Agency in May 2020, has approved the release of 750 million modified mosquitos. However, at the moment only 144,000 will be released during a three-month trial period. Nonetheless, some people in the trial areas are concerned.
Gravitas: Genetically modified mosquitoes arrive in Florida
16962P. Sharma, WION, 2021-05-06 15:03:25.
Genetically engineered mosquitoes have arrived in U.S. 20 million 'modified mosquitoes' will be released in Florida to help prevent Dengue. But, Florida residents fear a 'mosquito apocalypse'
Reengineered mosquitoes released in Florida pilot program
17021S. W. Tan, The Washington Times, 2021-05-06 13:12:32.
Genetically engineered mosquitoes have been released in the U.S. for the first time in the Florida Keys, with hopes of quelling wild, disease-carrying mosquito populations in the region. British-based biotech firm Oxitec genetically engineered Aedes aegypti non-biting male mosquitoes to carry a lethal gene that gets passed onto their offspring when they mate with wild biting female mosquitoes. The offspring are unable to survive, hence controlling the population of disease-carrying species, according to the Florida Keys Mosquito Control District (FKMCD), one of the entities that approved the firm’s project. Release boxes containing the genetically engineered male mosquitoes were placed in six locations last week — two on Cudjoe Key, one on Ramrod Key and three on Vaca Key — with thousands starting to emerge this month. Around 12,000 mosquitoes are expected to emerge each week for about 12 weeks.
First genetically modified mosquitoes released in US
16972N. Lanese, LiveScience, 2021-05-05 15:42:05.
The biotech firm Oxitec has released its genetically modified mosquitoes in the Florida Keys, with the goal of suppressing wild, disease-carrying mosquito populations in the region. This is the first time genetically modified mosquitoes have been released in the U.S. Oxitec previously released its modified Aedes aegypti mosquitoes in Brazil, the Cayman Islands, Panama and Malaysia, and the company reported that local A. aegypti populations fell by at least 90% in those locations, Live Science previously reported. A. aegypti can carry diseases such as Zika, dengue, chikungunya and yellow fever, and releasing modified mosquitoes offers a way to control the population without using pesticides. Oxitec's modified mosquitoes, all male, have been engineered to carry a lethal gene; when the modified pests mate with wild female mosquitoes, the lethal gene gets passed on to their offspring. Though the gene does not affect the males' survival, it prevents female offspring from building an essential protein and thus causes them to die before reaching maturity. Only female mosquitoes bite people (male mosquitoes exclusively drink nectar), so the modified mosquitoes and their surviving male offspring can't pass diseases to humans.
Bill Gates-backed startup releases millions of genetically modified mosquitoes
16952ENTREPRENEUR STAFF, Entrepreneur, 2021-05-04 20:35:48.
The British company Oxitec released a cloud of hundreds of millions of genetically modified mosquitoes to study how to control their reproduction and thus stop the spread of dengue, Zika, malaria, etc. As reported by Axios , the company, which is funded by the Bill and Melinda Gates Foundation , released the mosquitoes a week ago from the Florida Keys. In a statement, Oxitec explained that this experiment seeks to study ways to stop the reproduction of Aedes aegypti , the main transmitters of potentially fatal diseases. Why are Oxitec mosquitoes different? According to the company , the males in their insect cloud have a modified gene, called OX5034, that restricts the survival of the females they mate with. Thus, mosquitoes will not grow large enough to bite humans (only females consume blood; males feed on nectar). Oxitec noted that this species only represents 4% of the mosquito population in Florida, but it is the most disease-transmitting species. The startup has already released millions of modified insects around the world, including in Brazil and the Cayman Islands.
First US Field Test of GM Mosquitoes Begins in Florida
16950C. Wilcox, The Scientist, 2021-05-04 20:30:49.
he first US field test of genetically modified mosquitoes for population control has begun in Florida. Approximately 144,000 mosquitoes engineered by the UK-based biotech firm Oxitec are to be expected to be set free over the next three months, the first of up to 750 million approved for release over the next two years by the US Environmental Protection Agency. The trial aims to test whether the mosquitoes are effective at reducing populations of invasive Aedes aegypti, a species that can transmit dangerous diseases to people. The Florida Keys Mosquito Control District, which has partnered with Oxitec, has said this species makes up only 4 percent of the mosquito community in the Keys but is responsible for nearly all disease transmission and has become increasingly resistant to available pesticides, Nature reports. According to Oxitec, the modified mosquitoes are all male and carry a gene that makes female mosquitoes dependent on an antibiotic not available in the animals’ environment, thereby killing all of the male’s female offspring. Adult mosquitoes only live for a few weeks, and just the females bite, so the firm expects its modified males can spread the female-killing insert through the population and drastically reduce the number of potential disease vectors in the region. If successful, the mosquitoes could be used in place of pesticides in control efforts. A small but vocal group of Florida residents that has opposed the “mutant mosquitoes” from the get-go are continuing to seek legal action to stop it, CNN reports. Key Largo resident Mara Daly tells CNN she hopes “civil unrest happens,” and suggests residents could have their communities sprayed with pesticides in an effort to “opt out” of the trial.
The first transgenic mosquitoes were releaseed in the United States.
16947D. Davis, Prudent Press Agency, 2021-05-04 20:19:07.
After a decade of fighting for regulatory approval and public acceptance, the biotech company has released GMO mosquitoes outdoors in the United States for the first time. The experiment, which began this week in the Florida Keys, despite objections from some local critics, is testing a method for suppressing populations of wild Aedes aegypti mosquitoes, which can transmit diseases such as Zika, dengue fever, chikungunya and yellow fever mosquitoes. Oxitec, the UK-based company Abingdon that developed mosquitoes, has previously tested the insects in the field in Brazil, Panama, the Cayman Islands and Malaysia. But so far, due to a tortuous series of regulatory decisions and Florida residents’ disapproval (see “Long Road”), no GM mosquitoes have been tested in the United States, although the country had previously allowed evidence of a GM diamond. Moth (Plutella xylostella) in New York and pink worm (Pectinophora gossypiella) in Arizona, both developed by Oxitec. “When something new and revolutionary comes along, people’s immediate reaction is to say, ‘Wait,’” says Anthony James, a molecular biologist specializing in mosquito bioengineers at the University of California, Irvine. [Oxitec] Was able to conduct a trial on the ground in the United States a big problem. “
The Bill Gates Corporation, Backed by Bill Gates, Releases Thousands of Genetically Modified Mosquitoes
16975T. Meeks, Aviation Analysis, 2021-05-04 15:50:15.
British company Oxitec has launched transgenic mosquitoes in the Florida Keys, in the United States, to study how to control their reproduction and thus limit the spread of chronic diseases transmitted by insects such as dengue fever and the Zika virus. The company, funded by the Bill & Melinda Gates Foundation, announced the placement of its confined release funds, non-release funds, and quality control funds this week in six locations: two in Cudjoe Key, one in Ramrod Key, and three in Vaca Key. Why is the Oxitec mosquito different? According to the company, the males in its insect cloud carry a modified gene called OX5034, which restricts the survival of the females they mate with. As of early next month, fewer than 12,000 mosquitoes are expected to appear per week for about 12 weeks. Untreated comparison sites will be controlled with mosquito traps at Key Colony Beach, Little Torch Key, and Summerland Key. “We started looking at this a decade ago because we were in the middle of an outbreak of dengue fever in the Florida Keys,” Andrea Lyell, executive director of the Florida Keys area for mosquito control, said during a videoconference. “So we are very excited to further this partnership, and work with both Oxitec and members of the community.” Last year the Keys authorities approved the pilot project with mosquitoes Aedes aegyptiShe is not a Florida native. This insect transmits many diseases to humans, especially in the Keys island chain, where dozens of dengue cases were recorded last year.
Genetically modified mosquitos: Biohacking for disease prevention.
16941D. Maloney, HACKADAY, 2021-05-03 15:02:07.
Mosquito control is basically a numbers game, stacked in their favor. Since each female lays 100 to 200 eggs in a clutch, in wet climates, mosquitos are simply too prolific to get ahead of using standard means. Coupled with collateral damage to the environment — draining wetlands carries potentially huge impacts on a wide range of species, as does the indiscriminate use of pesticides — the search for new control methods with less harmful ecological side-effects has led to research into genetic methods of reducing mosquito populations. The idea of genetically engineering insects is nothing new. The fruit fly Drosophila melanogaster has had its genome extensively modified for over 100 years, first using standard mating and crossing techniques and later using transgenic methods to insert, delete, and edit genes. The result has been a wealth of knowledge about how the genetics of higher organisms work, as well as models for human diseases ranging from diabetes to Parkinson’s. But in general, transgenic fruit flies are simply model organisms destined to live and die in the lab. The concept of building a genetically modified insect for release into the wild is fairly new. Oxitec, the company behind the planned releases of transgenic mosquitos in Florida, has been working on the genetic control of a range of pest insect species since it was founded in 2002. They are currently on their second generation of genetically modified Aedes aegypti mosquitos, which is the insect that will soon be tested in Florida. The mosquito, dubbed OX5034, has been genetically engineered to be self-limiting. Both male and female OX5034 mosquitos carry a synthetic gene that is lethal only to females. The plan is to release OX5034 male mosquitos into a wild population where they’ll breed with unmodified females. These females will take a blood meal and lay eggs that carry the synthetic gene. Only the male eggs in the clutch will develop into adulthood; the females will all die during the larval and pupal stage, which will eventually reduce the number of blood meals taken and the potential for disease spread.
First genetically modified mosquitoes released in the United States
16939E. Waltz, Nature, 2021-05-03 14:56:33.
After a decade of fighting for regulatory approval and public acceptance, a biotechnology firm has released genetically engineered mosquitoes into the open air in the United States for the first time. The experiment, launched this week in the Florida Keys — over the objections of some local critics — tests a method for suppressing populations of wild Aedes aegypti mosquitoes, which can carry diseases such as Zika, dengue, chikungunya and yellow fever. Oxitec, the firm based in Abingdon, UK, that developed the mosquitoes, has previously field-tested the insects in Brazil, Panama, the Cayman Islands and Malaysia. But until now, owing to a circuitous series of regulatory decisions and pushback from Florida residents (see ‘A long road’), no genetically engineered mosquito had been trialled in the United States — even though the country previously allowed tests of a genetically engineered diamondback moth (Plutella xylostella) in New York and an engineered pink bollworm (Pectinophora gossypiella) in Arizona, both developed by Oxitec. “When something new and revolutionary comes along, the immediate reaction of a lot of people is to say: ‘Wait.’,” says Anthony James, a molecular biologist focused on bioengineered mosquitoes at the University of California, Irvine. “So the fact that [Oxitec] was able to get the trial on the ground in the United States is a big deal.”
Oxitec releases first genetically modified mosquitoes in U.S.
16928J. Knutson, Axios, 2021-05-01 15:46:09.
Oxitec, a British startup determined to prevent instances of mosquito-borne disease, released thousands of genetically modified mosquito eggs in the Florida Keys this week as part of a test approved by the Environmental Protection Agency and Florida's agriculture department. Why it matters: It marks the first release of genetically modified mosquitoes in the U.S. and has some locals worried about how this will impact the broader ecosystem, according to CNN. How it works: Oxitec expects to target Aedes aegypti, an invasive species of mosquito that carries several dangerous diseases like yellow fever, dengue and Zika virus.
Genetically modified mosquitoes have landed in the Keys. Here’s what you need to know
16918G. Filosa, Miami Herald, 2021-05-01 13:54:49.
More than 20 million genetically modified mosquitoes are coming to the Florida Keys this year, in a landmark project by British biotech company Oxitec and Monroe County’s Mosquito Control District. This mosquito control method hasn’t been used in the U.S. before. It’s a pilot program and the first trial began over the past week. The project is aimed at reducing the population of the invasive Aedes aegypti, which carries diseases like Zika. This is the first time in the country that the U.S. Environmental Protection Agency has issued the “experimental use permit” for this method.
What Are GMO Mosquitoes and What Is Their Purpose?
17038A. Krosofsky, GREENMATTERS, 2021-05-01 11:29:18.
Scientists have made GMO corn, strawberries, even many types of farm animals. Now, it seems, they have managed to genetically modify mosquitoes as well. But what is the purpose of GMO mosquitoes, and why would scientists go out of their way to create something that is already a problem for a huge portion of the planet’s population? As it turns out, GMO mosquitoes are a way to fight fire with fire. By creating and releasing their own genetically modified mosquitoes into existing populations, a few clever scientists have managed to curb the spread of dangerous mosquito-borne diseases like the Zika virus. According to the CDC, GMO mosquitoes are modified from the Aedes aegypti mosquito species. Aedes aegypti mosquitoes are commonly found in many parts of the U.S., including Florida and Texas. They are well known for spreading and carrying viruses like Zika, dengue, and chikungunya, but the GMO versions of these insects are designed to stop the spread of those diseases right at the source: the carriers themselves.
Genetically modified mosquitoes | Connect the Dots
16905thv11, THV11, 2021-04-30 17:56:23.
This is a local TV story from Arkansas of the Oxitec trial being conducted in Florida.
‘Home to GMO Mosquitoes?!’ Florida Unleashes a Billion Lab Grown Mosquitoes
16925Anonymous, B and T MAGAZINE, 2021-04-30 15:40:06.
Up to a billion genetically engineered mosquitoes are going to be released in the Florida Keys—but locals are having none of it, with billboards erected saying ‘no!’ to the damned blood suckers. The genetically-modified mosquitoes, known as the OX5034, were made in a laboratory in London by British biotech firm Oxitec, in a bid to kill-off a species in the Florida Keys that carries dengue fever, Zika virus, and yellow fever. It comes after more than 7,300 dengue cases were reported in the US in the past decade, Vice reports. While most were contracted outside America, 71 were transmitted in Florida, according to the CDC.
The Release of 1 Billion Exterminator Mosquitoes Has Begun
16922D. Noor, Gizmodo, 2021-04-30 15:32:45.
Tens of thousands of male mosquitoes are descending on the Florida Keys. But these are no ordinary mosquitoes: They’re genetically modified, and they were planted around the state on purpose. It’s part of a plan to curb disease by releasing 1 billion mosquitoes across two states—but it’s giving some folks the heeby jeebies. Workers placed boxes of mosquitoes’ eggs—two on Cudjoe Key, one on Ramrod Key and three on Vaca Key—on Thursday, and expect them to hatch in about a week. They’ll repeat the process over the coming months, releasing 12,000 of the bugs per week for 12 weeks. That’s 144,000 mosquitoes overall—gross. The project marks the first time GMO mosquitoes have ever been released in the U.S., was launched by the Florida Keys Mosquito Control District (FKMCD) with the private British firm biotech Oxitec. It’s an attempt to curb the spread of dengue, Zika and yellow fever.
First-ever US release of genetically modified mosquitoes begins in Florida Keys
16920S. LaMotte, CNN, 2021-04-30 15:27:44.
The first release of genetically modified mosquitoes in the United States began this week in the Florida Keys -- the culmination of a decade-long effort by local mosquito control authorities to see if a genetically modified organism is a viable alternative to spraying insecticides in the region.For the first 12-week phase, blue-and-white boxes containing about 12,000 GMO eggs developed by a US-owned, British-based company called Oxitec have been placed in six small areas of Ramrod Key, Cudjoe Key and Vaca Key. When water is added, the mosquitoes hatch, mature and enter the environment over the next week or so. A small, vocal group of Florida Key residents have fought the release of what they call "mutant mosquitoes" since the project was announced -- and they are incensed. "Our opposition has been long and strong," said Barry Wray, the executive director of the Florida Keys Environmental Coalition. "We live here, this our home, and they're forcing this down people's throats." "The only thing you can do legally at this point is stand in your yard with an insect fogger," said Mara Daly, a resident of Key Largo, Florida, who has fought the release for eight years. "You can't touch a box, but you can fog the s**t out of your own yard if you don't want to be a part of the trial."
The first genetically modified mosquitoes released in the U.S. to buzz in the Florida Keys
16897K. Weintraub, USA Today, 2021-04-29 17:37:24.
On Thursday morning, workers from a British company placed basketball-sized cardboard boxes into six yards in the Florida Keys. Then they added water. In a week or so, 12,000 male Aedes aegypti mosquitoes will – one by one – begin buzzing out of each box, the first genetically modified mosquitoes to be released in the United States. Local officials argue the trial is necessary at a time when pesticides are increasingly ineffective against these dangerous pests. A 2016 vote on the project claimed a solid majority of support in most of the surrounding counties. "At the end of the day, our hope is to be able to control this mosquito more efficiently and keep our population below any sort of disease transmission threshold," said Andrea Leal, executive director of the Florida Keys Mosquito District. "Our toolbox for Aedes aegypti control is shrinking, unfortunately, and that's making us think outside of the box."
A Billion Lab-Grown Mosquitos Are Being Released and People Are Freaking Out
16895V. Kipnis, Vice, 2021-04-29 17:08:03.
On Thursday afternoon, six Florida Keys residents will walk out into their yards and set out aquamarine cardboard boxes filled with mosquito larvae. Then, water will be poured into the containers. For the next ten days, as the mosquitoes grow into adults, their neighbors will be waiting to see what happens next. That’s because these aren’t just any mosquitoes: These are genetically-modified organisms, known as the OX5034, and they were made in a laboratory in London. Under a two-year Experimental Use Permit approved by the EPA, the British biotech firm Oxitec has been green-lit to release over 1 billion genetically modified mosquitoes across 6,600 acres in Florida and Texas. For their pilot project, they’re focusing on the lower Florida Keys, where in the coming 12 weeks, they plan to release 144,000 non-biting male mosquitoes from six different locations—making this the first time ever that a genetically-engineered mosquito will be let out into an open ecosystem in the United States.
The mosquito-bite fight begins
16883F. Billingsley, Click2Houston, 2021-04-29 15:10:43.
Anyone who thought February’s freeze would kill all the mosquitos is biting up the wrong leg. They are back and, seemingly so, with a vengeance (did surviving just make them stronger, one wonders?). In Florida this week, an interesting and controversial fight against the bite begins after more than a decade of getting there. The company Oxitec will be releasing 144,000 Genetically Modified Mosquitoes in the Florida Keys designed to fight the mosquito population. Did you ever take the antibiotic tetracycline? I took it to fight acne as a kid but it treats lots of other bacterial infections. Oxitec has engineered all their mosquitoes with a gene that makes only the females depend on tetracycline. Without it, the females die and it’s the females that bite. So all the eggs from the engineered mosquitoes will be shipped to Florida and when they hatch, the engineered female mosquitoes won’t have any tetracycline and they are toast.
Modeling and analysis of the implementation of the Wolbachia incompatible and sterile insect technique for mosquito population suppression.
17098B. Zheng, J. S. Yu and J. Li, Siam Journal on Applied Mathematics, 81:718-740. 2021-04-29 13:06:06.
Mathematical analysis may offer guidance in designing effective mass release strategies for the area-wide application of this Wolbachia incompatible and sterile insect technique in the future. The two most crucial concerns in designing release strategies are how often and in what amount should Wolbachia-infected mosquitoes be released in order to guarantee population suppression. Motivated by the experimental data from the Guangzhou mosquito factory and the release strategy implemented on two islands, we formulate and analyze a mosquito population suppression model considering the situation for the release period T less than the sexual lifespan of Wolbachia-infected males. We define release amount thresholds g(1)* and g(2)* with g(1)* < g(2)*. When the release amount c satisfies c >= g(2)*, population suppression is always achievable, as is mathematically manifested by the global asymptotic stability of the origin. However, when c is an element of (0, g(1)*], we find that suppression can be achieved only if the initial wild mosquito population is small enough. This is mathematically proved by the local asymptotic stability of the origin, together with the existence of exactly two T-periodic solutions, one of which is asymptotically stable and the other of which is unstable, with T being the waiting period between two consecutive releases. For c is an element of (g(1)*, g(2)*), we find sufficient conditions on the nonexistence of T-periodic solution, and the existence of at most two T-periodic solutions.
Nearly 144K GMO Mosquitoes to be Released in South Florida: What We Know
16902J. Prigeon, 6 South Florida, 2021-04-28 17:46:54.
Nearly 144,000 genetically modified mosquitoes will be released in South Florida this week as part of an effort to reduce the population disease-carrying mosquitoes. The landmark release of GMO insects marks the beginning of the U.S.-approved program to control the number of Aedes aegypti mosquitoes in the area. The project will place boxes loaded with Oxitec’s non-biting male mosquitoes in six areas around the Florida Keys to mate with biting female mosquitoes. As a result of the encounters, the female offspring will not survive and – hopefully – will reduce the dangerous mosquito's population in the area.
Nation’s first trial of genetically modified mosquitoes starts in Florida Keys
16889S. Brock, TODAY, 2021-04-28 15:15:04.
To control the population of potentially disease-spreading mosquitoes, a controversial project is getting underway in the Florida Keys, highlighted by the release of even more mosquitoes that have been genetically modified. NBC’s Sam Brock reports for TODAY from Miami.
Florida Unleashing Thousands of Mosquitoes
16886Anonymous, The Weather Channel, 2021-04-28 15:11:10.
Florida will begin releasing thousands of genetically modified mosquitoes in the Keys this week to combat diseases like Zika and dengue. But the government’s green light has some residents seeing red.
GMO mosquitoes to be released in Florida Keys
16880NBC News, WRCBtv, 2021-04-28 15:02:40.
Florida will begin releasing genetically modified mosquitoes this week as part of its efforts to control one of the disease-spreading species of the biting insect. The state will release almost 144,000 nonbiting male mosquitoes in the coming weeks engineered by the British firm Oxitec that are meant to mate with biting females, with any resulting female offspring unable to survive. The project was approved after years of public comment and official review. "As we are seeing development of resistance to some of our current control methods, we are in need of new tools to combat this mosquito," Andrea Leal, executive director of the Florida Keys Mosquito Control District said in a press release. The project is meant to control the population of the Aedes aegypti mosquito, which can spread dengue fever, Zika virus and yellow fever, as well as heartworm to pets and animals.
Nearly 150,000 Gene-Hacked Mosquitoes to Be Unleashed in Florida
16878S. Kim, Newsweek, 2021-04-28 14:58:55.
Nearly 150,000 mosquitoes that have been genetically modified by Oxitec, a biotechnology company based in the U.K., will be released across parts of Monroe County's Florida Keys region starting this week. The release is part of an experiment to help combat a disease-transmitting local mosquito population (the Aedes aegypti mosquito species) that is responsible for "virtually all mosquito-borne diseases transmitted to humans" such as dengue, Zika and yellow fever, the company says. Speaking to Newsweek, a spokesperson for Oxitec said: "We are releasing 12,000 [mosquitoes] per week for 12 weeks," which equates to a total of 144,000 mosquitoes, the spokesperson added. The experiment—a collaboration between the Florida Keys Mosquito Control District (FKMCD) and Oxitec—received approval from the U.S. Environmental Protection Agency (EPA) and the Florida Department of Agriculture and Consumer Services (FDACS). It is also supported by the U.S. Centers for Disease Control and Prevention as well as an independent advisory board, Oxitec says.
Genetically modified mosquito larvae to be released in Florida Keys
16869E. Helmore, The Guardian, 2021-04-28 14:13:40.
The Florida Keys will this week see the release of genetically modified, non-biting male mosquito larvae as part of a controversial program designed to curb the spread of insect-borne diseases such as dengue, Zika and yellow fever. The Florida Keys Mosquito Control District and British firm biotech Oxitec announced last week that 12,000 of the invasive Aedes aegypti mosquito species are expected to emerge each week for twelve weeks from six locations: two on Cudjoe Key, one on Ramrod Key and three on Vaca Key. US researchers seek citizen scientists as billions of Brood X cicadas set to emerge Eventually it is planned that hundreds of millions of the mosquitoes might be released. Oxitec’s non-biting male mosquitoes will mate with the local biting female mosquitoes and since the female offspring cannot themselves survive to reproduce, the population of Aedes aegypti is subsequently controlled. According to the CDC, the genetically modified mosquitoes carry two types of genes: a fluorescent marker gene that glows under a special red light, and a self-limiting gene that prevents female mosquito offspring from surviving to adulthood.
Florida set to release swarms of GMO mosquitoes as residents decry ‘criminal experiment’ by Bill Gates-backed biotech
16866rt com, rt com, 2021-04-28 14:04:30.
A plan to release thousands of genetically modified mosquitoes in an effort to combat disease in the Florida Keys has triggered dire concerns among locals, some saying the “criminal” experiment will turn them into guinea pigs. Spearheaded by the Florida Keys Mosquito Control District (FKMCD) and Oxitec, a British biotech firm that’s received backing from the Bill and Melinda Gates Foundation, the project aims to turn the first swarms of gene-edited bugs loose into the Keys starting sometime this week, the two bodies announced in a joint statement. For the first leg of the plan, set to be expanded later, mosquito boxes will be placed at six locations, which over 12 weeks will release around 144,000 Aedes aegypti mosquitoes, a species most closely linked with transmitting illnesses such as dengue, Zika and yellow fever. If all goes according to plan, the male, non-biting bugs will mate with local biting females, whose female offspring are programmed to die off, helping to control the Aedes aegypti population and reduce the spread of disease. While the particular species makes up only about 4% of the overall population in the Keys, it is behind “virtually all” mosquito-borne diseases passed to humans, as well as some that are transmitted to animals, such as heartworm, according to Oxitec.
BUZZ OFF Florida residents blast pest control ‘TERRORISTS’ over plans to unleash a BILLION mutant mosquitoes in the Keys
16857J. Bentley-York, The SUN, 2021-04-27 20:46:15.
The areas Mosquito Control District (FKMCD) are set to release the gene hacked ‘fraken-squitoes' in a bid to fight insect-borne viruses like yellow fever. A BILLION mutant mosquitoes are set to be released in the Keys to fight insect-borne viruses like yellow fever Florida pest control chiefs have been branded “terrorists” over the plans. The trial is set to begin this week, seeing a first phase of up to 144,000 modified mosquitoes released over the next 12 weeks. The project aims to reduce the numbers of Aedes aegypti species which are known for carrying diseases including dengue, chikungunya, zika and yellow fever. The male mosquitoes, developed by British biotech company Oxitect, do not bite, and will be introduced in small areas in a select number of neighborhoods in the Monroe area. However, Florida residents are calling on the US Environmental Protection Agency (EPA) to end "this live experiment" as they blasted the organisation as “terrorists.” Barry Wray of the Florida Keys Environmental Coalition said: “People here in Florida do not consent to the genetically engineered mosquitoes or to being human experiments.”
Florida to release a billion genetically modified mosquitoes and people are worried
16871B. Robinson, indy100, 2021-04-27 14:19:58.
It sounds like the pitch for a horror movie, but Florida’s about to release up to a billion genetically modified mosquitoes in the Keys. What could go wrong? Florida residents and environmentalists are already voicing their concerns after state officials and Oxitec, a biotechnology a UK-based biotechnology company, announced plans to release the critters over a two year period in Monroe County, in the Florida Keys section of the state. But why? In a press release from Friends of the Earth, they state that the project attempts to reduce the number of Aedes aegypti, one of the many species of mosquitoes that carry infectious diseases such as Yellow Fever and Zika.
Thousands of genetically modified mosquitoes being released in Florida
16863T. Lapin, New York Post, 2021-04-27 13:58:39.
Thousands of genetically modified mosquitoes have begun to be released in Florida this week as part of an effort to combat a disease-spreading species of the insect. The buzzy project, from British biotech company Oxitec, aims to curb the population of Aedes aegypti mosquitoes, which can spread diseases such as Zika and dengue fever, The Miami Herald reported. The project aims to have genetically modified male mosquitoes mate with non-modified females, which are the ones that bite. A so-called “death mechanism” would then act to prevent any resulting female offspring from surviving.
Halt This Nightmare’: Alarm as Florida Set to Begin Release of Genetically Engineered Mosquitoes
16861J. Johnson, Common Dreams, 2021-04-26 20:59:02.
Environmentalists and Florida residents voiced concern and outrage Monday as state government officials and the biotechnology giant Oxitec announced plans to move ahead this week with a pilot project that involves releasing up to a billion genetically engineered mosquitoes in Monroe County over a two-year period. Presented by local authorities as an effort to control the population of Aedes aegypti—a mosquito species that can carry both the dengue and yellow fever virus—critics warn that the effort's supposed benefits and its potential negative consequences have not been sufficiently studied. Responding to news that the first boxes of genetically modified mosquitos are set to be placed in six locations in Monroe County this week, Friends of the Earth noted in a press release that "scientists have raised concerns that GE mosquitoes could create hybrid wild mosquitoes which could worsen the spread of mosquito-borne diseases and could be more resistant to insecticides than the original wild mosquitoes."
Florida residents claim ‘pest control trial’ that will release up to a BILLION genetically engineered mosquitos in the Keys to reduce species carrying diseases is ‘TERRORISM’
16859S. Liberatore, Daily Mail, 2021-04-26 20:54:47.
The Florida Keys will soon be buzzing with close to a billion 'fraken-squitoes' – gene-hacked mosquitoes aimed at eradicating a disease carrying mosquito. The Florida Keys Mosquito Control District (FKMCD) and Oxitec, a British biotech company, are starting the first-ever U.S. release of genetically engineered (GE) Aedes aegypti mosquitoes this week, which will see up to a billion over a two-year period. The project aims to reduce the numbers of Aedes aegypti, one of several mosquito species that can carry diseases including dengue, chikungunya, Zika and yellow fever. Floridians, however, are calling on the US Environmental Protection Agency (EPA) to end 'this live experiment' saying they are being subjected to terrorism by the FKMCD.
Coalition Against GMO Mosquito Condemns Release of Genetically Engineered Mosquitoes
16853GMO Free USA, 3BL CSRwire, 2021-04-26 20:40:26.
Despite a decade of community opposition, the experimental release of genetically engineered mosquitoes begins today in the Florida Keys. British biotech corporation, Oxitec, in collaboration with the Florida Keys Mosquito Control District, plans to release up to a billion genetically engineered mosquitoes in two phases. GMO Free USA and the Coalition Against GMO Mosquitoes condemn the uncontrolled release and are airing radio spots to educate Florida Keys residents about the health and environmental risks. This unprecedented mass release of a genetically engineered insect is the first of its kind in the United States and many Florida Keys residents remain unaware. The Coalition Against GMO Mosquitoes recently launched an educational website, StopGMM.com, and sponsored a local billboard to increase public awareness and galvanize opposition. The new radio spot will run daily on multiple stations. Oxitec and the FKMCD have failed to provide sufficient answers to the most pressing questions posed by concerned residents. Some residents have reached out to government officials at the EPA, in Congress and the White House to request intervention to halt the experiment until thorough research is conducted.
Nation’s First Trial Of Genetically Modified Mosquitoes Starts In Florida Keys
16851N. Klingener, WLRN, 2021-04-26 20:35:50.
Boxes containing the eggs of genetically modified Aedes aegypti mosquitoes, water and a little food are being placed in six locations in the Lower and Middle Keys this week — in a trial that will be the first of its kind in the United States. The genetic modification is intended so that female offspring won't survive. Female mosquitoes are the ones that bite and can transmit diseases like dengue and zika. The genetically modified males are supposed to breed with wild females — and then their female offspring won't survive, either. Andrea Leal is in charge of the Florida Keys Mosquito Control District. The district has been working with the British firm Oxitec for more than a decade, since a 2009-10 outbreak of dengue fever in Key West.
Scientists are now playing god with mosquitoes
16794M. Wehner, BGR, 2021-04-15 13:13:24.
Preventing illnesses in humans is a high priority for scientists that devote their lives to finding cures and techniques that keep people healthy, but sometimes a plan comes along that is so wild it can cause even the most devoted science fans to furrow their brow. In Florida, dengue fever regularly sickens over 100 people per year, and many of those individuals that contracted the virus are believed to have received it locally via mosquitos. Now, in what can only be described as the real-life equivalent of a made-for-TV sci-fi movie, scientists in Florida are prepared to unleash a swarm of genetically modified mosquitoes that will hopefully cut down on the number of the biting insects and, as a result, lower the numbers of mosquito-borne illnesses. The company behind the “OX5034” modified mosquitos is called Oxitec, and while it’s gained approval from the Environmental Protection Agency, there are still plenty of critics that fear unforeseen consequences.
First GMO mosquitoes to be released in the Florida Keys
16688T. White, UNDARK, 2021-04-12 15:18:49.
Oxitec says its technology will combat dengue fever, a potentially life-threatening disease, and other mosquito-borne viruses — such as Zika — mainly transmitted by the Aedes aegypti mosquito. While there have been more than 7,300 dengue cases reported in the United States between 2010 and 2020, a majority are contracted in Asia and the Caribbean, according to the U.S. Centers for Disease Control and Prevention. In Florida, however, there were 41 travel-related cases in 2020, compared with 71 cases that were transmitted locally. Native mosquitoes in Florida are increasingly resistant to the most common form of control — insecticide — and scientists say they need new and better techniques to control the insects and the diseases they carry. “There aren’t any other tools that we have. Mosquito nets don’t work. Vaccines are under development but need to be fully efficacious,” says Michael Bonsall, a mathematical biologist at the University of Oxford, who is not affiliated with Oxitec but has collaborated with the company in the past, and who worked with the World Health Organization to produce a GM mosquito-testing framework.
Why do you think a gene drive approach could help with malaria and dengue?
16682Outreach Network for Gene Drive Research, 2021-04-12 14:42:36.
Why do you think a gene drive approach could help with malaria and dengue?
Transgenic mosquito resistant to multiple serotypes of the dengue virus
34972Department of Chemistry, Faculty of Science, University of Colombo in collaboration with the Molecular Medicine Unit, Faculty of Medicine, University of Kelaniya, University of Colombo, 2021-04-10 10:39:01.
The dengue virus causes epidemics in more than 100 tropical and sub-tropical countries, where over 2.5 billion people (over 40% of the world’s population) are currently at risk of dengue infections. In recent years, dengue has become the number one vector-borne disease in Sri Lanka. The worst ever dengue virus outbreaks experienced in 2009, 2010, and 2013 transformed dengue into a major health issue in Sri Lanka. There are no medicines or effective vaccines developed for dengue; therefore, mosquito vector control is the most promising option to control dengue virus transmission. The conventional vector control methods used currently have only limited success. In an attempt to find a solution to this problem, the research team lead by Professor Ranil Dassanayake, Department of Chemistry, University of Colombo in collaboration with Professor Nilmini Gunawardene, Molecular Medicine Unit, Faculty of Medicine, University of Kelaniya undertook to develop a dengue virus resistant transgenic Aedes aegypti mosquito (the primary vector of dengue virus transmission) line using an RNA interference (RNAi) based technology, as a component of the Ph.D. research project of Mr. Kalindu Ramyasoma.
Village hears from experts as genetic-mosquito release experiment nears.
16678J. McCarthy, KEYSWEEKLY, 2021-03-26 14:56:47.
On March 18, Islamorada Village Council heard from several independent scientists who discussed information and issues behind the genetically modified mosquitoes for population and disease suppression. The scientists collectively said they’re neither for nor against the release. A representative from the Florida Keys Mosquito Control District and one from Oxitec responded following the presentation. Fred Gould, professor of North Carolina State’s Department of Entomology and Plant Pathology, briefly explained the strain of mosquitoes (OX5034) set for release. He said he was involved with another strain of genetically modified mosquitoes in development in 2010 when a field case study was conducted in Mexico. “In the laboratory, it turned out the male mosquitoes flew fine and mated well. But in the real environment, they weren’t as strong as the wild type mosquitoes and they basically had 3% of the matings. Instead of having half the matings, they had very few,” he said. Gould went on to say that this is also shown in work by Oxitec in Brazil, where it turns out that the genetic mosquitoes “are not very fit.” “It would take 30 of them, at least, to be equal to an individual wild type in terms of how many matings you have,” he said. “When you’re thinking about that, you have to recognize you have to release a lot of mosquitoes in order to have any activity. I just want to bring that home to you that it goes up and down as to what that percent fitness is, and we don’t know what that’ll look like in Florida. “Will it work? I want to say it might work just fine,” he continued. “There’s a chance that they’ll be doing these releases and it won’t be a simple thing.”
Sterile Insect Technique in an Integrated Vector Management Program against Tiger Mosquito Aedes albopictus in the Valencia Region (Spain): Operating Procedures and Quality Control Parameters
16663C. Tur, D. Almenar, S. Benlloch-Navarro, R. Argilés-Herrero, M. Zacarés, V. Dalmau and I. Pla, Insects, 12. 2021-03-23 14:20:04.
The Agriculture Department of the Valencian Region is promoting an ongoing pilot project to evaluate the efficacy of an integrated vector management program (IVM) based on the use of the SIT as the main method of control. The laboratory studies for evaluating the entomological efficacy of SIT through the phased conditional testing process recommended by World Health Organization and the International Atomic Energy Agency (WHO-IAEA) are addressed. This study describes the routine operating procedures and quality control parameters for the medium-scale rearing of sterile male A. albopictus. More than 15 million sterile males have been produced and released in an area of 80 ha between 2018 and 2020. Of the initial L1 larvae, we recovered 17.2% of male pupae after sex sorting to be sterilized and released on the field, while the rest of the pupae remained available to maintain the rearing colony. The residual percentage of females after sex sorting was on average 0.17%. The obtained values in terms of production and quality control as well as the proposed rearing methodology can be useful for designing a medium-scale mosquito-rearing pipeline.
Mosquito anxiety prompts query from congressman
16592T. Java, Keynews.com, 2021-03-10 20:09:26.
Anxiety among some residents over the pending release of hundreds of millions of genetically modified mosquitoes next month in undisclosed locations throughout the Florida Keys has prompted Congressman Carlos Gimenez to seek answers from the U.S. Environmental Protection Agency. The Florida Keys Mosquito Control District and Oxitec, a British-based biotech company, plan to release genetically modified Aedes aegypti mosquitoes in selected neighborhoods between mile markers 10 and 93 as a way to control the wild population of the disease-carrying pest. This is the first experiment of its kind in the U.S.
Eliminating Mosquitoes with Precision Guided Sterile Males
16563M. Li, T. Yang, M. Bui, S. Gamez, T. Wise, N. P. Kandul, J. Liu, L. Alcantara, H. Lee, J. R. Edula, R. Raban, Y. Zhan, Y. Wang, N. DeBeaubien, J. Chen, H. M. Sanchez C, J. B. Bennett, I. Antoshechkin, C. Montell, J. M. Marshall and O. S. Akbari, bioRxiv, 2021.03.05.434167. 2021-03-06 20:07:26.
Here we develop a molecular genetic control system termed precision guided sterile insect technique (pgSIT) in Aedes aegypti. PgSIT uses a simple CRISPR-based approach to generate sterile males that are deployable at any life stage. Supported by mathematical models, we empirically demonstrate that released pgSIT males can compete, suppress, and eliminate mosquitoes in multigenerational population cages. This platform technology could be used in the field, and adapted to many vectors, for controlling wild populations to curtail disease in a safe, confinable, and reversible manner.
Tensions rise as GM mosquito release nears in Florida Keys
16520T. O'Hara, Keynews.com, 2021-03-03 20:29:44.
Tensions seem to be rising as a planned release of genetically modified mosquitoes nears. The British-based biotech company Oxitec plans to release genetically modified Aedes aegypti mosquitoes in the Florida Keys sometime after April, but has yet to disclose exact locations in the Keys or a date.
Florida Keys moves forward with genetically modified mosquitoes
16524H. Vela, local10.com, 2021-03-03 18:08:13.
The feared GMO mosquitoes are not going away. Opponents of the technology fear the date of the release in the Florida Keys is getting closer, and they are not ready for the possible repercussions of the experiment. The fight over whether or not to release genetically modified mosquitoes in Monroe County has been going on for almost a decade. Barry Wray said the mosquito control team’s contractor wants to deliver the first batch in April. Wray, the executive director of the Florida Keys Environmental Coalition, said he doesn’t believe there is enough evidence to prove that the technology is safe. He said there is a need for independent scientific investigation. “You don’t really know what the long-term outcomes could be or how to quantify those risks, and if you can’t do that scientifically, then you don’t know how to responsibly mitigate it or detect if something is going awry,” Wray said.
When and where will millions of mosquitoes be released? Here are details for Florida Keys
16485D. Goodhue, Miami Herald, 2021-02-25 21:09:17.
The Florida Keys Mosquito Control District announced this week a wide and vague planned range of deployment for the lab-designed mosquitoes — neighborhoods from mile marker 10 to 93. The trial is being conducted by British biotech company Oxitec. It’s a method approved by the U.S. Environmental Protection Agency, the state of Florida, and the mosquito control district’s five-member board, to try to eradicate or significantly reduce the local population of Aedes aegypti mosquitoes.
Mosquito trial will begin in April, but Keys locations won’t be disclosed
16483S. Matthis, KEYSWEEKLY, 2021-02-23 20:54:42.
FKMCD spokesman Chad Huff wrote in an email, “The physical location of each box is still being finalized. Since most will be situated on private property at owner request, FKMCD-Oxitec will NOT be providing specific addresses due to privacy concerns and protection of project integrity.” Phil Goodman, chairman of the FKMCD said the decision to keep addresses confidential was an operations decision, not a decision by the elected board. “Right now, we don’t have any specific sites that are 100 percent selected,” said Andrea Leal, executive director of the FKMCD. “We are just narrowing down areas with potential.”
Oxitec gears up for test releases
16386T. O'Hara, Keynews.com, 2021-02-10 15:10:19.
The United Kingdom-based biotech company Oxitec will soon announce the test locations and timetable for releasing its genetically modified mosquitoes in the Florida Keys.
Number of Project Wolbachia mosquitoes released is constantly reviewed to maintain suppression of dengue: NEA
16388N. L. Ching, today, 2021-02-09 15:12:34.
Project Wolbachia – Singapore has yielded promising results so far.Releases of non-biting male Wolbachia-Aedes mosquitoes have suppressed the urban Aedes aegypti mosquito populations in study sites at Tampines and Yishun by up to 90 per cent, and we have observed 58 to 74 per cent less dengue cases in 2020 in areas where releases have been ongoing for at least a year compared to areas without releases. However, this does not mean that there will be no dengue cases in the study sites, especially in the initial period, because it takes several months for the releases to bring down the dengue mosquito population.While some residents at the release sites have noticed more non-biting mosquitoes around their homes, the released male mosquitoes do not bite, and the overall data shows a clear benefit — fewer dengue cases.
How to engage communities on a large scale? Lessons from World Mosquito Program in Rio de Janeiro, Brazil [version 2; peer review: 1 approved, 2 approved with reservations]
16361G. B. Costa, R. Smithyman, S. L. O'Neill and L. A. Moreira, Gates Open Research, 2021-02-04 19:26:09.
Here we discuss and analyse the framework for community engagement implemented by the WMP in Brazil, during the large-scale deployment of the method in the municipalities of Niterói and Rio de Janeiro, Brazil. Our experience indicates that the community engagement work for arboviruses control should be understood as an opportunity for local development. It is necessary, based on an integrated analysis of the territory, to understand that the actions for arboviruses control could be a catalyst for the necessary socioenvironmental, cultural and public health changes. Furthermore, it is essential to understand that community engagement goes beyond informing or asking for population consent, but it constitutes a possibility for dialogue and exchange between the various stakeholders present in the territories, to build on cooperation for mosquito-borne disease control.
Sexual Competitiveness and Induced Egg Sterility by Aedes aegypti and Aedes albopictus Gamma-Irradiated Males: A Laboratory and Field Study in Mexico
17760J. G. Bond, S. Aguirre-Ibáñez, A. R. Osorio, C. F. Marina, Y. Gómez-Simuta, R. Tamayo-Escobar, A. Dor, P. Liedo, D. O. Carvalho and T. Williams, Insects, 12. 2021-01-29 14:44:07.
The sterile insect technique may prove useful for the suppression of mosquito vectors of medical importance in regions where arboviruses pose a serious public health threat. In the present study, we examined the effects of sterilizing irradiation doses across different ratios of fertile:irradiated males on the mating competitiveness of Ae. aegypti and Ae. albopictus under laboratory and field-cage conditions. For both species, the percentage of females inseminated and the number of eggs laid over two gonotrophic cycles varied significantly in mating treatments involving 1:1, 1:5, and 1:10 fertile:irradiated males compared to controls of entirely fertile or entirely irradiated males but was not generally affected by the irradiation dose. Egg hatching was negatively affected in females exposed to increasing proportions of irradiated males in both laboratory and field cages. Male competitiveness (Fried’s index) values varied from 0.19 to 0.58 in the laboratory and were between 0.09 and 1.0 in field cages, depending on th species. Competitiveness values were negatively affected by th eirradiation dose in both species under field-cage conditions, whereas in the laboratory, Ae. albopictus was sensitive to the dose but Ae. aegypti was not. In general, male competitiveness was similar across all mating regimes. Most importantly, induced egg sterility was positively correlated with the proportion of irradiated males present in the mating treatments, reaching a maximum of 88% under field-cage conditions for both Ae. aegypti and Ae. albopictus males treated with 50 and 40 Gy irradiation, respectively. These results indicate that sterile males produced at our facility are suitable and competitive enough for field pilot SIT projects and provide guidance to decide the optimal sterile:fertile ratios.
Population Dynamics of Aedes aegypti and Aedes albopictus in Two Rural Villages in Southern Mexico: Baseline Data for an Evaluation of the Sterile Insect Technique
17758C. F. Marina, J. G. Bond, K. Hernández-Arriaga, J. Valle, A. Ulloa, I. Fernández-Salas, D. O. Carvalho, K. Bourtzis, A. Dor, T. Williams and P. Liedo, Insects, 12. 2021-01-11 14:36:35.
Indoor and outdoor ovitraps were placed in 15 randomly selected houses in two rural villages in Chiapas, southern Mexico. In addition, ovitraps were placed in five transects surrounding each village, with three traps per transect, one at the edge, one at 50 m, and another at 100 m from the edge of the village. All traps were inspected weekly. A transect with eight traps along a road between the two villages was also included. Population fluctuations of Aedes aegypti and Ae. albopictus were examined during 2016–2018 by counting egg numbers. A higher number of Aedes spp. eggs was recorded at Hidalgo village with 257,712 eggs (60.9%), of which 58.1% were present in outdoor ovitraps and 41.9% in indoor ovitraps, compared with 165,623 eggs (39.1%) collected in the village of Río Florido, 49.0% in outdoor and 51.0% in indoor ovitraps. A total of 84,047 eggs was collected from ovitraps placed along transects around Río Florido, compared to 67,542 eggs recorded from transects around Hidalgo. Fluctuations in egg counts were associated with annual variation in precipitation, with 2.3 to 3.2-fold more eggs collected from ovitraps placed in houses and 4.8 to 5.1-fold more eggs in ovitraps from the surrounding transects during the rainy season than in the dry season, respectively. Aedes aegypti was the dominant species during the dry season and at the start of the rainy season in both villages. Aedes albopictus populations were lower for most of the dry season, but increased during the rainy season and predominated at the end of the rainy season in both villages. Aedes albopictus was also the dominant species in the zones surrounding both villages. The numbers of eggs collected from intradomiciliary ovitraps were strongly correlated with the numbers of eggs in peridomiciliary ovitraps in both Río Florido (R2adj = 0.92) and Hidalgo (R2adj = 0.94), suggesting that peridomiciliary sampling could provide an accurate estimate of intradomiciliary oviposition by Aedes spp. in future studies in these villages. We conclude that the feasibility of sterile insect technique (SIT)-based program of vector control could be evaluated in the isolated Ae. aegypti populations in the rural villages of our baseline study.
Wolbachia strain wAlbB maintains high density and dengue inhibition following introduction into a field population of Aedes aegypti
15689N. A. Ahmad, M.-V. Mancini, T. H. Ant, J. Martinez, G. M. R. Kamarul, W. A. Nazni, A. A. Hoffmann and S. P. Sinkins, Philosophical Transactions of the Royal Society B: Biological Sciences, 376:20190809. 2020-12-28 15:06:28.
Here, wAlbB-carrying Ae. aegypti collected from the field 20 months after the cessation of releases showed no reduction in Wolbachia density or tissue distribution changes compared to a wAlbB laboratory colony. The wAlbB strain continued to induce complete unidirectional cytoplasmic incompatibility, showed perfect maternal transmission under laboratory conditions, and retained its capacity to inhibit dengue. Additionally, a field-collected wAlbB line was challenged with Malaysian dengue patient blood, and showed significant blocking of virus dissemination to the salivary glands.
CRISPR/Cas9 knockout of female-biased genes AeAct-4 or myo-fem in Ae. aegypti results in a flightless phenotype in female, but not male mosquitoes
15617S. O’Leary and Z. N. Adelman, PLOS Neglected Tropical Diseases, 14:e0008971. 2020-12-18 16:05:35.
Author summary Ae. aegypti is the most important vector of arboviruses throughout the world, and new strategies are urgently needed to add to our existing arsenal of control methods to prevent or halt disease transmission. Importantly, only female Ae. aegypti mosquitoes transmit arboviruses due to their need for vertebrate blood to support egg production. Here, we identify several genes that are critical only for female mosquito flight; genetic ablation of each gene resulted in flightless females, but flying males. Importantly, the female flightless phenotype was completely penetrant (100%), and the use of sex-biased flight muscle proteins appeared to be conserved throughout mosquito evolution. These data could be used to support the development of novel genetic control approaches to reduce the number of biting females across a wide range of disease vector species.
Reply to: “Enhancement of Aedes aegypti susceptibility to dengue by Wolbachia is not supported”
15264C. Souto-Maior, J. G. King, L. M. Sartori, R. Maciel-de-Freitas and M. G. M. Gomes, Nature Communications, 11:6113. 2020-11-30 19:09:46.
Ant et al.4 claim that concerns with the data and broader analysis make our conclusions misleading. We herein respond to their comments by demonstrating the robustness of our results to different treatments of the data, and expand our arguments for replacing currently adopted methods by those introduced in our paper.
Enhancement of Aedes aegypti susceptibility to dengue by Wolbachia is not supported
15258T. H. Ant, M.-V. Mancini, J. Martinez and S. P. Sinkins, Nature Communications, 11:6111. 2020-11-30 18:48:33.
King et al.3 used DENV infection and transmission modelling to reinterpret experimental data from two previous studies4,5. The authors claimed that wMel Wolbachia increase the mean susceptibility of Ae. aegypti to DENV, contradicting various other studies6,7,8,9,10,11,12. Here, we raise concerns with the experimental approaches used to generate one of the primary datasets on which the modelling is based, and we discuss how these limitations could make some of the original conclusions misleading.
Fighting Mosquito With GMO Mosquito: The Battle Brewing in the Florida Keys
15005S. MacLaughlin, NBC 6 South Florida, 2020-11-06 15:32:04.
Scientists are a few months into an experiment to stop the invasive Aedes aegypti mosquito. Their weapon of choice? A genetically modified mosquito. But some environment advocates question the strategy. This year, the Florida Keys had an outbreak of Dengue fever, which was the first time that had happened in 10 years. It gives new urgency to the controversial effort to get rid of the Aedes aegypti, which has become harder to fight.
Florida will release 750 million genetically modified mosquitoes
14998S. McGlaun, Slash Gear, 2020-11-05 15:14:43.
Local officials in Florida have announced that they have approved 750 million genetically modified mosquitoes to be released into the environment to reduce local populations of the bloodsucking creatures. The goal of releasing genetically modified mosquitoes is to help reduce the number of mosquitoes carrying diseases like dengue or the Zika virus. Approval to release the bugs came after environmental groups warned of unintended consequences.
Stable Introduction of Plant-Virus-Inhibiting Wolbachia into Planthoppers for Rice Protection
19719J. T. Gong, Y. Li, T. P. Li, Y. Liang, L. Hu, D. Zhang, C. Y. Zhou, C. Yang, X. Zhang, S. S. Zha, X. Z. Duan, L. A. Baton, X. Y. Hong, A. A. Hoffmann and Z. Xi, Current Biology, 30:4837-4845.e5. 2020-10-10 12:20:07.
Progress has been made in developing the maternally inherited endosymbiotic bacterium Wolbachia as a tool for protecting humans from mosquito-borne diseases. In contrast, Wolbachia-based approaches have not yet been developed for the protection of plants from insect pests and their associated diseases, with a major challenge being the establishment of artificial Wolbachia infections expressing desired characteristics in the hemipterans that transmit the majority of plant viruses. Here, we report stable introduction of Wolbachia into the brown planthopper, Nilaparvata lugens, the most destructive rice pest that annually destroys millions of hectares of staple crops. The Wolbachia strain wStri from the small brown planthopper, Laodelphax striatellus, was transferred to this new host, where it showed high levels of cytoplasmic incompatibility, enabling rapid invasion of laboratory populations. Furthermore, wStri inhibited infection and transmission of Rice ragged stunt virus and mitigated virus-induced symptoms in rice plants, opening up the development of Wolbachia-based strategies against major agricultural pests and their transmitted pathogens
You should be excited that scientists are releasing 750 million genetically modified mosquitoes this year
14568L. Westreich, Massive Science, 2020-09-27 19:27:28.
GM mosquitoes are successful in reducing mosquito populations, and reducing disease spread
The Con Job at Mosquito Control Board
14571E. Russo and B. Wray, keysnews.com, 2020-09-26 19:32:07.
Shouldn’t there be a consensus among scholars, scientists, experts and the public that this new technology is safe?
How to fight the deadly dengue virus? Make your own mosquitoes
14320J. Emont, Wall Street Journal, 2020-09-07 15:13:25.
When the bacteria-laden male mosquitoes are released into the open and mate with naturally-born females, the resultant eggs won’t hatch.
GMOs make war on mosquitoes
14323Staff, Kenosha News, 2020-09-05 15:13:38.
Given that recent record, we were a bit surprised to read that there was a ruckus over genetically modified mosquitoes going on in the Florida Keys.
Why Genetically Modified Mosquitoes Won’t Come to Texas Anytime Soon
14317C. Adams, RA News, 2020-09-04 15:03:04.
Talks about releasing genetically modified mosquitoes in Houston began in 2018 between Harris County and Oxitec, a United Kingdom-based company that produces sustainable technologies or transgenic methodologies to stem the impact of disease-spreading insects. Talk also began about a similar action in Monroe County, Fla.
Non-GMO approach reduces cases of mosquito-borne dengue by 77%
14239GM Watch, GM Watch, 2020-08-31 13:55:39.
A randomized field trial found that mosquitoes infected with a natural bacterium called Wolbachia reduced cases of dengue by an "extraordinary" 77%.
An accident waiting to happen: Tech company to release 750 MILLION GMO mosquitoes in Florida to fight dengue fever
14232Z. Sky, NEWSTARGET, 2020-08-30 20:31:13.
Oxitec plans to release 750 million OX5034s into the Florida Keys, something that sounds like the beginning of a doomed science-fiction movie. But the most shocking thing here is the fact that Oxitec received the EPA’s approval in May.
Genetically-modified mosquito plan offers hope for Keys, world
14256P. Goodman, keynews.com, 2020-08-29 14:25:12.
The Florida Keys Mosquito Control District Board of Commissioners voted 4-to-1 to approve a trial using Oxitec’s second-generation genetically modified mosquitoes. I
Bacteria-Laced Mosquitoes Limit Spread of Dengue
14244A. Heidt, The Scientist, 2020-08-29 14:05:32.
Researchers have infected Aedes aegypti mosquitoes—the species responsible for passing on many diseases—with bacteria called Wolbachia with the intent of reducing the insects’ ability to pass on dengue to people.
The good mosquito versus the bad
14240D. Datta, Business Standard, 2020-08-29 14:01:00.
Starting 2021, around 750 million genetically modified (GM) Aedes Aegypti mosquitoes will be released in batches into the Florida Keys.
Florida Will Release 750 Genetically Modified Mosquitoes to Stop Disease Spread
14177A. Fahmy, verywell health, 2020-08-28 14:36:32.
The hope is to prevent the spread of Dengue fever, a painful virus acquired only by mosquito bite which made a reappearance in the Florida Keys in 2009.
Scientists infect mosquitoes with bacteria to stop the transmission of dengue fever in Indonesia, dropping infection rates by 77 percent
14250D. Avery, Daily Mail, 2020-08-28 14:15:52.
The team found that dengue infections were 77 percent lower in treated neighborhoods, compared to areas not exposed to the infected insects.
The mosquito strategy that could eliminate dengue
14170E. Callaway, Nature, 2020-08-27 14:19:52.
The study, conducted in an Indonesia city, showed that releasing mosquitoes modified to carry a bacterium called Wolbachia, which stops the insects from transmitting some viruses, led to a steep drop in cases of dengue fever.
Researchers Find New Approach To Control Dengue, Zika By Genetically Modifying Mosquitoes
14247N. Sharma, R. Republicworld.com, 2020-08-27 14:11:56.
A new study carried out in Indonesia has shown that dengue infection rates decreased in regions where the genetically modified mosquitoes were introduced.
Australian research takes aim at dengue, another killer virus
14226E. Connors, Finanacial Review, 2020-08-26 20:22:39.
Australian researchers have teamed up with Indonesian philanthropists to strike a blow against dengue fever, the deadly disease that was a growing scourge in south-east Asia and South America long before COVID-19.
Australian scientists slash dengue fever in Indonesia by infecting mosquitoes with bacteria
14224A. Barker, ABC News, 2020-08-26 20:17:56.
Australian scientists may have found the secret to eradicating dengue fever, with a lengthy trial in Indonesia drastically reducing the incidence of the mosquito-borne virus.
Deep dive: Florida’s GM mosquito experiment aims to rewrite rules of vector-borne diseases
14084S. Kannan, India Today, 2020-08-26 14:33:36.
A pathbreaking bioengineering experiment on mosquito populations that could have massive implications for tropical malaria-affected countries like India has got underway in Florida, US.
Fighting mosquito-borne diseases… with mosquitoes
14156N. Gubert and A. Baubeau, Phys Org, 2020-08-26 13:13:41.
For decades, researchers have scratched their heads over how to combat deadly mosquito-borne diseases such as dengue fever.
Bug board OKs release of genetically modified mosquitoes
14151T. O'Hara, keynews.com, 2020-08-26 13:08:07.
After nearly 10 years of debate, the Florida Keys Mosquito Control District board has approved an agreement with biotech company Oxitec to conduct a test release of genetically modified mosquitoes in Monroe County as part of a mosquito limiting or eradication plan.
Genetically modified mosquitoes to be released in the Florida Keys to combat dengue, zika, and yellow fever.
14148Yucatan Times, Yucatan Times, 2020-08-26 13:04:27.
The Florida Keys will be the scene of the first test in the United States with genetically modified Aedes aegypti mosquitoes, an alternative to insecticides and larvicides to end the transmission of diseases such as dengue, zika and yellow fever that has always been surrounded by controversy.
750 million genetically modified mosquitoes soon released in the wild!
14093explica, explica, 2020-08-25 14:42:52.
Rather frightening mosquitoes will be released on an archipelago in Florida. The goal? Reduce the population of their more dangerous congeners who can transmit certain diseases.
US to Use Genetically Modified Mosquitoes to Fight Dengue Fever
14090H. Badr, Asharq Al-Awsat, 2020-08-25 14:39:32.
After a decade of discussions, officials in Florida have voted to allow the first test in the United States of free-flying, genetically modified mosquitoes that kill any female offspring, as a way to fight the pests and the diseases they spread.
Florida Keys to Use Genetically Modified Mosquitoes to Fight Disease
14087B. Lynn, Voice of America, 2020-08-25 14:33:57.
Officials in the Florida Keys plan to release genetically modified mosquitoes next year in an effort to fight insect-borne diseases.
Florida Approves Controversial Plan to Release 750 Million Genetically Modified Mosquitoes
14096D. Rakshit, Swaddle, 2020-08-24 14:46:17.
Authorities in Florida have approved a pilot project that will release 750 million genetically modified mosquitoes locally, in a bid to reduce the populations of mosquitoes that cause that cause dengue, Zika, chikungunya, and yellow fever
Mutant bugs released to fight disease
14081The Day, The Day, 2020-08-24 14:20:37.
Authorities have approved the scheme in Florida but environmental groups are furious, calling it a “Jurassic Park experiment” that will unleash a “mutant bug” into the ecosystem.
More than 750 million GMO mosquitoes to be released over Florida Keys – what could go wrong?
14145E. Huff, Natural News, 2020-08-24 12:59:20.
The Florida Keys Mosquito Control District (FKMCD) has given Oxitec, a corporation we have reported on in the past, permission to unleash some 750 million GMO mosquitos in Monroe County, Florida, over the next two years.
Florida to release genetically modified mosquitoes to prevent diseases like Zika
14009The West News, The West News, 2020-08-23 17:50:16.
Local authorities on Tuesday gave final approval to release 750 million genetically modified mosquitoes in the Florida Keys over a two-year period, starting in 2021.
Genetically modified mosquitoes have been OK’d for a first U.S. test flight
14003S. Milius, ScienceNews, 2020-08-22 17:44:31.
After a decade of fits and starts, officials in the Florida Keys have voted to allow the first test in the United States of free-flying, genetically modified mosquitoes as a way to fight the pests and the diseases they spread.
Florida Will Release Genetically Modified Mosquitoes to Fight Disease in the Keys
14000S. Harrell, Spectrum News, 2020-08-21 17:40:14.
Following lengthy federal and state procedures, the Florida Keys Mosquito Control District this week approved a plan to release more than 750 million genetically modified mosquitoes in the Keys region to combat an invasive, disease-carrying species of the insect.
Florida is releasing 750 million genetically modified mosquitoes into the world. Here’s why
13992H. Schriber, Deseret News, 2020-08-21 17:35:50.
Florida officials plan to release 750 million genetically modified mosquitoes into the Florida Keys over the next two years as a way to prevent diseases like the Zika virus. The project will begin in 2021. The Environment Protection Agency approved the idea in May. The project will test if one of these mosquitoes can work better than spraying insecticides to stop these insects from spreading potentially fatal viruses, according to CNN.
Genetically Modified Mosquitoes To Be Released In Florida Keys
13989A. Snow, The Daily Wire, 2020-08-21 17:33:00.
CNN reported that the genetically modified bugs, called OX5034, have been “altered to produce female offspring that die in the larval stage, well before hatching and growing large enough to bite and spread disease.” Since it’s the female of the species that bite, they are the ones that carry diseases. Males, the outlet reported, eat nectar.
Release 750 Million Genetically Modified Mosquitoes Into the Wild, They Said
13986C. Delbert, Popular Mechanics, 2020-08-21 17:31:14.
Corporate scientists have received final approval from the Environmental Protection Agency (EPA) to release hundreds of millions of genetically altered mosquitoes into the Florida Keys. The goal? To begin reining in the mosquito population, which is only expected to increase as climate change continues to warm and flood the low-lying, tropical Keys. But some environmental groups object strongly to the move.
Florida releasing genetically modified mosquitoes to prevent diseases like Zika
13984N. Lanese, LiveScience, 2020-08-21 17:29:18.
Hundreds of millions of genetically modified mosquitoes will soon be released in the Florida Keys island chain to wipe out local populations of disease-carrying mosquitoes, according to news reports.
750 Million GM Mosquitoes Will Be Released in the Florida Keys
13982L. Winter, The Scientist, 2020-08-21 17:27:30.
With the aim of reducing rates of the mosquito-borne illnesses yellow fever and dengue, a pilot program will release 750 million genetically modified mosquitoes into the Florida Keys in 2021, thanks to approval by the barrier islands’ Mosquito Control District Board of Commissioners at a meeting on Tuesday (August 18)
Hundreds Of Millions Of Genetically Modified Mosquitoes Approved For Release In US
13996J. Vibes, Anonymous News, 2020-08-20 17:37:24.
A Biotech company called Oxitec has received permission from the government to release hundreds of millions of genetically modified male mosquitoes in the Florida Keys.
Why Hundreds of Millions of Genetically Engineered Mosquitoes Will Soon Be Released in Florida
13979K. Gander, Newsweek, 2020-08-20 17:22:07.
Hundreds of millions of genetically engineered mosquitoes will soon be released in Florida, in a first for the U.S. On Tuesday, the Florida Keys Mosquito Control District (FKMCD) approved plans to release the insects, who do not bite, as part of a pilot project launching next yea
Florida to release genetically modified mosquitoes, detractors blast ‘Jurassic Park’ experiment
13969D. Aaro, Fox News, 2020-08-20 15:49:28.
Local authorities on Tuesday gave final approval to release 750 million genetically modified mosquitoes in the Florida Keys over a two-year period, starting in 2021, with the hope of preventing diseases such as the Zika virus but has faced blowback and comparisons to a Steven Spielberg thriller.
750 million genetically modified mosquitoes to be released across Florida Keys
13966A. Zahid, Sky News, 2020-08-20 15:47:05.
Authorities have approved plans for genetically modified mosquitoes to be released across the Florida Keys from next year. British-based firm Oxitec has designed the project to test whether the altered mosquitoes are a viable alternative to pesticides to control and prevent the spread of diseases, including Zika and dengue.
750 million GM mosquitos set for release in Florida Keys.
13961Editorial Staff, E&T, 2020-08-20 15:43:13.
Local authorities have approved proposals to release hundreds of millions of genetically modified (GM) modified mosquitos in Florida, in an effort to control populations of diseases spread by the organism.
Florida Plans to Fix Its Mosquito Problem With 750 Million More Mosquitoes
13959D. Noor, Gizmodo, 2020-08-20 15:40:34.
Hundreds of millions of mosquitos will soon be released in Florida. On purpose. The mosquitoes are being released as a form of pest control, but they could wreak havoc on local ecosystems.
Florida mosquitoes: 750 million genetically modified insects to be released
13955BBC, BBC, 2020-08-20 15:37:01.
Local officials in Florida have approved the release of 750 million mosquitoes that have been genetically modified to reduce local populations. The aim is to reduce the number of mosquitoes that carry diseases like dengue or the Zika virus.
Florida OKs release of genetically modified mosquitoes in Keys to slow insect disease spread
13952S. Mann, Just the News, 2020-08-20 15:34:23.
Florida officials are authorizing a biotech company to release hundreds of millions of genetically-modified male mosquitoes into the Florida Keys to reduce future mosquito populations that spread diseases including yellow fever and malaria.
Florida Keys to release modified mosqutioes to fight illness
13949C. Anderson, Associated Press, 2020-08-20 15:30:15.
Sometime next year, genetically modified mosquitoes will be released in the Florida Keys in an effort to combat persistent insect-borne diseases such as Dengue fever and the Zika virus. The plan approved this week by the Florida Keys Mosquito Control District calls for a pilot project in 2021 involving the striped-legged Aedes aegypti mosquito, which is not native to Florida.
Florida to Release Millions of Genetically Modified Mosquitoes Against Local Residents’ Wishes
13946N. Rice, People, 2020-08-20 15:27:38.
A plan to release over 750 million genetically modified mosquitoes in the Florida Keys has received final approval. According to CNN, on Tuesday, local authorities approved a plan to release the genetically modified mosquitoes in the Sunshine State's string of islands, with the hope of preventing a string of diseases that the insects can carry.
Plan to Release 750M GMO Mosquitoes Gets Go Ahead
13944R. Quinn, newser, 2020-08-20 15:23:41.
The plan to release the genetically modified Aedes aegypti mosquitoes received final approval from local authorities Tuesday, causing an outcry from groups opposed to what they call a "Jurassic Park experiment," CNN reports.
‘A Jurassic Park Experiment’: Watchdog Groups Denounce Decision to Release Genetically Modified Mosquitoes in Florida
13975L. Newcomb, Common Dreams, 2020-08-19 15:54:09.
Food safety and environmental groups Wednesday condemned a decision by officials in Florida to approve the release of 750 million genetically modified mosquitoes, a pilot project aimed at reducing the spread of mosquito-borne diseases.
Florida Keys to release 750M genetically modified mosquitoes
13972D. Haynes, UPI, 2020-08-19 15:51:58.
Local authorities in the Florida Keys gave their approval Wednesday to a plan to release genetically modified mosquitoes to prevent the spread of dengue fever and other diseases. The Monroe County Mosquito Control District signed off on the project, which would release about 750 million mosquitoes engineered to produce dead offspring.
FKMCD Board Approves Oxitec Pilot
14929C. Huff, FKMCD in the News, 2020-08-19 15:48:10.
The Florida Keys Mosquito Control District’s (FKMCD) five member board has APPROVED a proposal by Oxitec to utilize non-biting male, genetically modified mosquitoes as part of a trial to determine their effectiveness in controlling the wild population of Aedes aegypti, the mosquito which is responsible for spreading diseases such as dengue fever. FKMCD and Oxitec have both said that the pilot project will not take place until 2021. The FKMCD board’s four to one vote in FAVOR comes after Federal and State approvals of an ‘Experimental Use Permit’ issued earlier this summer by the Environmental Protection Agency and The Florida Department of Agriculture and Consumer Services. F
To combat disease-spreading mosquitoes in the Keys, leaders vote to unleash lab bugs
13964D. Goodhue, Miami Herald, 2020-08-19 15:44:52.
Florida Keys officials have voted to allow the experimental release of millions of genetically modified mosquitoes into a yet-to-be-decided area of the island chain.
Genetically Modified Mosquitoes Cleared for Florida Keys Release
13901J. Kay, Bloomber Law, 2020-08-18 13:36:35.
Genetically engineered mosquitoes will be released in the Florida Keys in 2021 to try to reduce the population of a biting insect pest that spreads Zika, dengue fever, and yellow fever, local officials said Tuesday.
Incorporating Characteristics of Gene Drive Engineered Ae. aegypti as Methods to Reduce Dengue and Zika Virus into the Bayesian Network – Relative Risk Model, Using Ponce, Puerto Rico as a Case Study
16097S. R. Eikenbary, WWU Graduate School Collection, 2020-08-10 19:24:02.
The Bayesian network relative risk model can perform the risk assessment of gene drive engineered Ae. aegypti for vector control and as part of an adaptive management strategy to reduce dengue and Zika transmission. This study illustrates how the BN-RRM can integrate gene drive related information within a risk assessment framework suitable for adaptive management of these novel stressors.
Modeling the suppression dynamics of Aedes mosquitoes with mating inhomogeneity
13847M. Huang and L. Hu, Journal of Biological Dynamics, 14:656-678. 2020-08-04 13:51:41.
In this work, we introduce a delay differential equation model with mating inhomogeneity to discuss mosquito population suppression based on Wolbachia. Our analyses show that the wild mosquitoes could be eliminated if either the adult mortality rate exceeds the threshold δ∗A or the release amount exceeds the threshold r∗ uniformly. Our simulations suggest that the releasing should be started at least 5 weeks before the peak dengue season, taking into account both the release amount and the suppression speed.
Genetically modified mosquitoes could be released in Florida
13587wqad.com, WQAD8, 2020-07-30 12:51:49.
Cases of dengue fever are on the rise in the Florida Keys. One biotech company wants to release genetically modified mosquitoes for a pilot program.
Tackling Dengue fever by turning female mosquitoes into males
13482T. Sandle, DIGTAL JOURNAL, 2020-07-22 21:00:41.
T. Sandle (2020). DIGTAL JOURNAL Genetic engineering appears to be the key for delivering mosquito control, according to new research. Scientists have successfully converted female mosquitoes into non-biting males.
Genetically Modified Mosquitoes Approved For Insect Population Control In The U.S.
12705J. Blum, HUFFPOST, 2020-06-18 20:45:30.
Genetically modified mosquitoes with the ability to prevent other mosquitoes from spreading deadly diseases may be making their way to Florida backyards in the near future. British biotech group Oxitec announced on Tuesday that the company had won both federal and state approval to release its so-called “Friendly” mosquitoes in the U.S. on an experimental trial basis, expected to last until 2022, according to documents provided by the Environmental Protection Agency. The insects will first be released in Monroe County, Florida, and Oxitec has plans to also bring them tT Harris County, Texas.
Florida says ‘this is fine’ to release of genetically modified mosquitoes
12703J. K. Elliot, Global News, 2020-06-18 20:43:23.
That’s the question hanging over a recent decision by state regulators in Florida, which would allow the biotech company Oxitec to unleash hundreds of millions of genetically modified male mosquitoes in the Florida Keys. The lab-altered, patented insects are members of Aedes aegypti, the species of mosquito that spreads diseases such as yellow fever, malaria and chikungunya. However, they’ve been genetically altered to artificially reduce future mosquito populations.
Plan to Release GMO Mosquitoes Moves Ahead
12700A. Dier, newser, 2020-06-18 20:40:30.
A plan to set loose 750 million genetically modified mosquitoes in Florida and Texas will move forward despite concerns from environmentalists who liken it to a "Jurassic Park experiment." The non-biting male Aedes aegypti mosquitoes developed by British biotechnology company Oxitec contain a protein, passed to biting female offspring, that is designed to reduce the insect's chance of surviving into adulthood and therefore prevent the spread of mosquito-borne diseases including Zika and West Nile, reports the Guardian. The EPA has approved two trials, in which the mosquitoes are to be released in Florida's Monroe County this summer and in Texas' Harris County in 2021, though it's facing a lawsuit over its alleged failure to investigate the environmental impact, per the Hill. Facing similar complaints, Florida nonetheless approved its trial on Tuesday.
Genetically engineered mosquitoes get EPA approval for Florida release despite objections from environmental groups
12697S. LaMotte, CNN Health, 2020-06-18 20:37:52.
A genetically modified male mosquito named OX5034 has received both state and federal approval to be released into the Florida Keys now through 2022, against the objection of many local residents and a coalition of environmental advocacy groups. "The administration has used tax dollars and government resources for a Jurassic Park experiment, except without the island," said Jaydee Hanson, policy director at the International Center for Technology Assessment and Center for Food Safety, in a statement.
Florida Keys plans killer insect attack on disease-carrying mosquitoes
12693P. Brinkmann, UPI, 2020-06-18 20:33:39.
The Florida Keys is close to adding a new weapon to help control a mosquito-borne disease -- genetically modified mosquitoes that produce dead offspring. Outbreaks of dengue fever in the Keys in recent years prompted local authorities to consider the genetically modified bugs because the Aedes aegypti mosquito, which spreads that and other diseases, has shown resistance to pesticides.
Detecting the population dynamics of an autosomal sex ratio distorter transgene in malaria vector mosquitoes
13607P. Pollegioni, A. R. North, T. Persampieri, A. Bucci, R. L. Minuz, D. A. Groneberg, T. Nolan, P. A. Papathanos, A. Crisanti and R. Muller, Journal of Applied Ecology, 11. 2020-06-18 12:44:16.
A sex-distorting autosomal transgene has been developed recently in G3 mosquitoes, a laboratory strain of the malaria vectorAnopheles gambiaes.l. Following the World Health Organization guidance framework for the testing of GM mosquitoes, we assessed the dynamics of this transgene in large cages using a joint experimental modelling approach. We performed a 4-month experiment in large, indoor cages to study the population genetics of the transgene.
Plan to release genetically modified mosquitoes in Florida gets go-ahead
12695O. Milman, The Guardian, 2020-06-17 20:35:58.
A plan to release a horde of 750 million genetically modified mosqutioes in Florida and Texas is a step closer to fruition after a state regulator approved the idea, over the objections of many environmentalists.
EPA faces suit over plan to release genetically engineered mosquitoes
12457R. Frazin, The Hill, 2020-06-15 20:36:28.
The Environmental Protection Agency (EPA) is facing a lawsuit over its approval of a plan to release genetically modified mosquitoes in Florida and Texas
Scientists hope to release genetically-modified mosquitoes
12437Fox 13, Fox 13, 2020-06-09 20:18:09.
Apparently, scientists are interested in releasing genetically-modified mosquitoes in Florida in order to help battle the spread of certain diseases.
Can we kill the dreaded mosquito? Do we even want to?
11228Stacey McKenna, Sierra, 2020-04-19 15:40:08.
As a major vector for disease, the mosquito has harmed more human beings than just about any other animal, and a changing climate is only boosting those numbers. As the range of disease-carrying species of mosquitoes expands, so does their ability to transmit the parasites and viruses that result in malaria, chikungunya, Zika, yellow fever, West Nile, and dengue fever. In 2018, the continental United States saw a 25 percent increase in severe, neuroinvasive cases of West Nile virus compared with a decade earlier. And over the past three decades, the CDC reports, the worldwide incidence of dengue fever has risen 30-fold.
Editorial Expression of Concern: Transgenic Aedes aegypti Mosquitoes Transfer Genes into a Natural Population
16199B. R. Evans, P. Kotsakiozi, A. L. Costa-Da-Silva, R. S. Ioshino, L. Garziera, M. C. Pedrosa, A. Malavasi, J. F. Virginio, M. L. Capurro and J. R. Powell, Scientific Reports, 10:2. 2020-03-24 15:17:41.
Shortly after publication of this Article in September 2019, the Editors were alerted to concerns regarding the interpretation of the data and some of the conclusions.
Engineering Bugs, Resurrecting Species: The Wild World of Synthetic Biology for Conservation
7242P. Rejcek, Singularity Hub, 2020-02-02 15:56:24.
Imagine a world where a mosquito bite is just an itchy annoyance. No malaria. No dengue fever. Last month, scientists announced they had taken one more step toward that vision. A paper in the journal PLOS Pathogens described how they synthetically engineered mosquitoes to stop the spread of dengue fever, a viral tropical disease that sickens as many as 100 million people each year. Now imagine genetically tweaking an invasive species of mosquito to save native Hawaiian birds from extinction, or transferring genes from one species of endangered chestnut tree to another to help the latter resist blight. Employing the same sort of genetic engineering used to make a plant-based burger bleed, scientists are beginning to explore the ways synthetic biology could help protect biodiversity and conserve species.
Synthetically engineered mosquitos could neutralize dengue virus infection
6943L. Woolfe, Biotechniques, 2020-01-22 15:59:46.
Dengue virus infection can be severe and life threatening. New research has developed an improved approach to controlling this deadly infection.
Mosquitoes genetically modified to combat dengue
6740Downtoearth, Down To Earth, 2020-01-20 20:22:34.
For the first time mosquitoes have been engineered to fight all 4 known types of dengue
Genetically Modified Mosquitos Neutralize Dengue Virus
6737N. P. Dyal, Infectious Disease Advisor, 2020-01-20 18:53:09.
Researchers at the University of California San Diego have identified a target gene in mosquitos that renders the insects completely refractory to all 4 serotypes of the dengue virus and thus, incapable of transmitting the virus to humans, according to study results published in PLoS Pathogens
Genetically modified mosquitoes resist all dengue viruses, researchers find
6709B. Burton, C|NET, 2020-01-17 18:24:25.
This new kind of mosquito can't spread any form of the deadly disease.
Genetically engineered mosquitoes resist spreading any form of dengue
6734K. Servick, Science, 2020-01-16 18:50:53.
Recover from dengue once, and you’re not necessarily free and clear. The mosquito-borne disease marked by fever, rash, and debilitating pain results from any of four genetically distinct versions of the dengue virus. Previously infected people who get hit with a second of these “serotypes” can face more severe, even life-threatening symptoms. Now, by endowing a line of mosquitoes with an antibody against the virus, researchers have for the first time made insects that—at least in lab tests—appear unable to spread any form of the disease. In theory, these mosquitoes could be released into the wild to suppress the circulation of the virus.
Genetically engineered mosquitoes halt Dengue spread
6730L. Thomas, New Medical Life Sciences, 2020-01-16 18:44:27.
A new study published in the journal PLOS Pathogens in January 2020 reports the development of mosquitoes that have been genetically modified to resist infection by several types of the dengue virus. This is the first time ever that all types of the virus have been targeted by the engineering of the mosquito DNA. Covering all virus types is essential to achieve proper disease control.
Researchers Genetically Modify First Batch Of Mosquitoes Resistant To All Four Types Of Dengue
6725M. Dapcevich, IFL Science, 2020-01-16 18:39:05.
An international team of researchers have synthetically engineered a breed of mosquitos that are resistant to all four types of the dengue virus for the first time, a feat they say may someday suppress the disease and stop its transmission to humans.
Genetically engineered mosquitoes are immune to all strains of dengue virus for first time
6719G. Weule, ABC News Online, 2020-01-16 18:34:13.
Locked in a secure lab near Melbourne is the newest addition in the fight against dengue: genetically engineered mosquitoes that are resistant to all strains of the potentially deadly virus.
Mosquitoes resistant to all types of dengue virus engineered
6714N. Lavars, New Atlas, 2020-01-16 18:28:54.
Last year, scientists at Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) made a big breakthrough, engineering mosquitoes that break the chain of Zika virus transmission. But they did so with multiple targets in mind, with the mosquito in question, Aedes aegypti, also acting as the number one disease vector for the dengue virus. The researchers have now added this arrow to the quiver of their genetically-modified mosquitoes, with hopes of tackling what they see as a global epidemic.
Broad dengue neutralization in mosquitoes expressing an engineered antibody
6706A. Buchman, S. Gamez, M. Li, I. Antoshechkin, H.-H. Li, H.-W. Wang, C.-H. Chen, M. J. Klein, J.-B. Duchemin, J. E. Crowe, Jr., P. N. Paradkar and O. S. Akbari, PLOS Pathogens, 16:e1008103. 2020-01-16 18:18:14.
Author summary With limited success of traditional vector control methods to curb dengue infections and more than half of the world’s population still at risk, there is a need for novel strategies to reduce its impact on public health. Recent advances in genetic technologies has allowed for precise modifications of mosquito genome to make them resistant to infections, thus breaking the transmission cycle. Here we generated engineered Ae. aegypti mosquitoes efficiently expressing a DENV-targeting single-chain variable fragment (scFv) derived from a previously characterized broadly neutralizing human antibody, which blocked infection and transmission in these mosquitoes. To our knowledge, this is the first example of an engineered transgene capable of rendering Ae. aegypti mosquitoes 100% refractory to all four serotypes of DENV. The engineered mosquitoes, in future, could easily be paired with a gene drive, capable of spreading the transgene throughout wild disease-transmitting mosquito populations and preventing further DENV transmission. Since a number of diverse and well-characterized antibodies exist against other arboviruses (eg chikungunya and Zika, this work also provides a proof-of-concept principle for developing similar genetic strategies for reducing the impact of these arboviruses.
Development of a confinable gene drive system in the human disease vector Aedes aegypti
6697M. Li, T. Yang, N. P. Kandul, M. Bui, S. Gamez, R. Raban, J. Bennett, H. M. Sánchez C, G. C. Lanzaro, H. Schmidt, Y. Lee, J. M. Marshall and O. S. Akbari, eLife, 9:e51701. 2020-01-16 18:07:34.
Aedes aegypti is the principal mosquito vector for many arboviruses that increasingly infect millions of people every year. With an escalating burden of infections and the relative failure of traditional control methods, the development of innovative control measures has become of paramount importance. The use of gene drives has sparked significant enthusiasm for genetic control of mosquitoes; however, no such system has been developed in Ae. aegypti. To fill this void, here we develop several CRISPR-based split gene drives for use in this vector. With cleavage rates up to 100% and transmission rates as high as 94%, mathematical models predict that these systems could spread anti-pathogen effector genes into wild populations in a safe, confinable and reversible manner appropriate for field trials and effective for controlling disease. These findings could expedite the development of effector-linked gene drives that could safely control wild populations of Ae. aegypti to combat local pathogen transmission.
The potential cost-effectiveness of controlling dengue in Indonesia using wMel Wolbachia released at scale: a modelling study
14326O. J. Brady, D. D. Kharisma, N. N. Wilastonegoro, K. M. Reilly, E. Hendricx, L. S. Bastos, L. Yakob and D. S. Shepard, medRxiv, 2020.01.11.20017186. 2020-01-16 17:55:32.
Wolbachia releases in high density urban areas is expected to be highly cost-effective and could potentially be the first cost saving intervention for dengue. Sites with strong public health infrastructure, fiscal capacity, and community support should be prioritized.
Malaysia Wolbachia trials: Battling dengue and other mosquito-borne viruses
170592019-11-22 13:47:09.
Establishment of Wolbachia Strain wAlbB in Malaysian Populations of Aedes aegypti for Dengue Control
17089W. A. Nazni, A. A. Hoffmann, A. NoorAfizah, Y. L. Cheong, M. V. Mancini, N. Golding, G. M. R. Kamarul, M. A. K. Arif, H. Thohir, H. NurSyamimi, M. Z. ZatilAqmar, M. NurRuqqayah, A. NorSyazwani, A. Faiz, F.-R. M. N. Irfan, S. Rubaaini, N. Nuradila, N. M. N, Current Biology, 29:4241-4248.e5. 2019-11-21 15:20:44.
Dengue has enormous health impacts globally. A novel approach to decrease dengue incidence involves the introduction of Wolbachia endosymbionts that block dengue virus transmission into populations of the primary vector mosquito, Aedes aegypti. The wMel Wolbachia strain has previously been trialed in open releases of Ae. aegypti; however, the wAlbB strain has been shown to maintain higher density than wMel at high larval rearing temperatures. Releases of Ae. aegypti mosquitoes carrying wAlbB were carried out in 6 diverse sites in greater Kuala Lumpur, Malaysia, with high endemic dengue transmission. The strain was successfully established and maintained at very high population frequency at some sites or persisted with additional releases following fluctuations at other sites. Based on passive case monitoring, reduced human dengue incidence was observed in the release sites when compared to control sites. The wAlbB strain of Wolbachia provides a promising option as a tool for dengue control, particularly in very hot climates.
Transgenic Aedes aegypti Mosquitoes Transfer Genes into a Natural Population
16197B. R. Evans, P. Kotsakiozi, A. L. Costa-da-Silva, R. S. Ioshino, L. Garziera, M. C. Pedrosa, A. Malavasi, J. F. Virginio, M. L. Capurro and J. R. Powell, Scientific Reports, 9:6. 2019-09-10 15:09:04.
We genotyped the release strain and the target Jacobina population before releases began for >21,000 single nucleotide polymorphisms (SNPs). Genetic sampling from the target population six, 12, and 27-30 months after releases commenced provides clear evidence that portions of the transgenic strain genome have been incorporated into the target population. Evidently, rare viable hybrid offspring between the release strain and the Jacobina population are sufficiently robust to be able to reproduce in nature. The release strain was developed using a strain originally from Cuba, then outcrossed to a Mexican population. Thus, Jacobina Ae. aegypti are now a mix of three populations. It is unclear how this may affect disease transmission or affect other efforts to control these dangerous vectors. These results highlight the importance of having in place a genetic monitoring program during such releases to detect un-anticipated outcomes.
Engineered Reciprocal Chromosome Translocations Drive High Threshold, Reversible Population Replacement in Drosophila
3961Buchman, ABI, Tobin; Marshall, John M.; Akbari, Omar S.; Hay, Bruce A., ACS Synthetic Biology, 7:1359-1370. 2018-01-19 00:00:00.
Replacement of wild insect populations with transgene-bearing individuals unable to transmit disease or survive under specific environmental conditions using gene drive provides a self-perpetuating method of disease prevention. Mechanisms that require the gene drive element and linked cargo to exceed a high threshold frequency in order for spread to occur are attractive because they offer several points of control: they bring about local, but not global population replacement; and transgenes can be eliminated by reintroducing wildtypes into the population so as to drive the frequency of transgenes below the threshold frequency required for drive. Reciprocal chromosome translocations were proposed as a tool for bringing about high threshold population replacement in 1940 and 1968. However, translocations able to achieve this goal have only been reported once, in the spider mite Tetranychus urticae, a haplo-diploid species in which there is strong selection in haploid males for fit homozygotes. We report the creation of engineered translocation-bearing strains of Drosophila melanogaster, generated through targeted chromosomal breakage and homologous recombination. These strains drive high threshold population replacement in laboratory populations. While it remains to be shown that engineered translocations can bring about population replacement in wild populations, these observations suggest that further exploration of engineered translocations as a tool for controlled population replacement is warranted.
Regulatory experience and challenges for the release of GM insects
4135Beech, C, Journal Fur Verbraucherschutz Und Lebensmittelsicherheit-Journal of Consumer Protection and Food Safety, 9:S71-S76. 2014-01-13 00:00:00.
Genetically modified (GM) insects are a potentially valuable new tool for the biological control of insect pests of humans, animals and plants. Considerable progress has been made recently in transfer of GM insects from the laboratory to release and evaluation in the environment. As with other new genetic technologies, regulatory agencies have often found it challenging to determine the regulatory regime under which they should be evaluated, and have either adapted existing regulatory frameworks or adopted new ones. No country has legislation specifically for GM insects. However, irrespective of the regulatory regime under which they are evaluated, the purpose of their regulation remains the same; to protect human health and the environment. Consequently there are evaluation themes common to their regulatory scrutiny, which are elucidated here. There have also been some challenges and issues encountered during the risk evaluation for field release of GM insects, and this paper will highlight some of these to assist others when considering policy, regulation and assessment of GM insects. Useful regulatory and policy precedents also exist from the regulation of biological control agents and the global protection of plants from pests under the International Standards for Phytosanitary Measures (ISPM) framework. Where countries do not have existing regulations, these evaluation instruments could have the potential to be adapted to form a suitable framework for the assessment of risk for GM insects. Finally, some considerations for future policy and regulation in this area are discussed.
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