How to fight the deadly dengue virus? Make your own mosquitoes

Tags: Dengue, Genetic biocontrol, Incompatible insect technique, Oxitec, Sterile insect technique (SIT), Wolbachia
J. Emont, Wall Street Journal, 2020.

Government researchers wheeled containers teeming with penned-up mosquitoes through a dense apartment complex at the city state’s northern tip. Over the next couple of hours, they periodically lifted the lids, allowing swarms of the insects to fly loose.

Releasing mosquitoes into the corridors of apartment complexes might seem like an unusual strategy for a city fighting its worst recorded outbreak of dengue, a painful disease spread between humans by mosquitoes. But the thousands of little insects discharged last week weren’t your average mosquitoes.

They were bred in a laboratory to carry a substance not commonly found in this type of mosquito: bacteria called Wolbachia. When the bacteria-laden male mosquitoes are released into the open and mate with naturally-born females, the resultant eggs won’t hatch.

The outcome is reduced number of dengue cases in the areas where the lab-bred insects were released, according to Singapore’s government.

Scientists and governments are expanding high-tech solutions like these as the threat from the dengue virus grows. Some are using genetically engineered mosquitoes; others are zapping them with X-ray beams to sterilize them.