The Evolving Arsenal Against Mosquito-Born Diseases

J. Smith,,  2020.

As the global climate continues to warm, disease-spreading mosquitoes such as Aedes aegypti are expected to establish themselves in the US and Europe. This could result in explosive outbreaks of debilitating mosquito-borne infections such as dengue fever, Zika, and chikungunya. At the same time, some of the most effective control methods, chemical insecticides, are starting to lose the fight against insecticide resistance.

The UK company Oxitec, owned by the US firm Third Security, is making big headlines lately for its efforts to prevent mosquito-borne infections. Last month, the company received approval to launch the first US pilot study of Aedes aegypti mosquitoes that are genetically engineered to reduce the numbers of the wild population.

Oxitec does this by releasing genetically altered males into the affected area, which mate with wild females to produce offspring. If the offspring is male, it survives to mate again. But if the offspring is female, it dies straight away, reducing the wild population while also limiting the spread of the death-causing gene.

This is just part of Oxitec’s strategy though. Of the surviving male offspring, one half carries the lethal gene, while the other half carries genes that make the insects vulnerable to insecticides. So not only can the wild mosquito population contract, but it could also become less resistant to common chemical control methods.

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