A Mosquito Factory?!

A “mosquito factory” might sound like the last thing you’d ever want, but Brazil is constructing a facility capable of producing five billion mosquitoes annually. The twist? The factory will breed mosquitoes carrying a special bacteria that significantly reduces their ability to transmit viruses. As far as I can tell, however, the new mosquitoes still suck your blood.

Nature: The bacterium Wolbachia pipientis naturally infects about half of all insect species. Aedes aegypti mosquitoes, which transmit dengue, Zika, chikungunya and other viruses, don’t normally carry the bacterium, however. O’Neill and his colleagues developed the WMP mosquitoes after discovering that A. aegypti infected with Wolbachia are much less likely to spread disease. The bacterium outcompetes the viruses that the insect is carrying.

When the modified mosquitoes are released into areas infested with wild A. aegypti, they slowly spread the bacteria to the wild mosquito population.

Several studies have demonstrated the insects’ success. The most comprehensive one, a randomized, controlled trial in Yogyakarta, Indonesia, showed that the technology could reduce the incidence of dengue by 77%¹, and was met with enthusiasm by epidemiologists.

In Brazil, where the modified mosquitoes have so far been tested in five cities, results have been more modest. In Niterói, the intervention was associated with a 69% decrease of dengue cases². In Rio de Janeiro, the reduction was 38%³.

Wolbachia-infected mosquitoes have already been approved by Brazilian regulatory agencies. But the technology has not yet been officially endorsed by the World Health Organization (WHO), which could be an obstacle to its use in other countries. The WHO’s Vector Control Advisory Group has been evaluating the modified mosquitoes, and a discussion about the technology is on the agenda for the group’s next meeting later this month.