GMO mosquitoes project going well, biotech firm says

Insects altered to fight disease, researchers say

The release of genetically modified mosquitoes in the United States created to fight disease has gone according to plan, biotechnology firm Oxitec says.

The first phase of the pilot study consisted of releasing almost five million modified Aedes aegypti male mosquitoes in the Florida Keys, a group of islands off the southern tip of Florida, in April 2021.

The results indicated that the method may eventually succeed in eradicating or downsizing the number of Aedes aegypti mosquitoes.

Aedes aegypti only make up four per cent of the mosquito population in the Keys, but are responsible for spreading yellow fever, dengue, chikungunya and Zika virus, Oxitec said during an online seminar revealing their findings on April 6.

“The mosquito is very difficult to control. It likes to live around people, in houses, under houses,” said Andrea Leal, executive director of the Florida Keys Mosquito Control District. “We’re also seeing an increase in resistance to a number of our adulticide products that we use for mosquito control, so at the end of it, we’re looking for new tools to put in our tool box to help us control this particular mosquito.”

Especially because the Florida Keys are surrounded by a national marine sanctuary, Leal added, it’s important to look at methods that don’t have environmental impacts.

Oxitec also clarified that modified male mosquitoes don’t bite people.

Select neighbourhoods in the Florida Keys were given mosquito boxes that genetically modified males emerge from and then seek the wild females in order to breed.

The modified males carry a gene that kills female offspring. Researchers observed 22,000 larvae taken from the areas where the males were released. None of the female larvae that were the offspring of the modified males lived into adulthood. Meanwhile, the male offspring ended up carrying the modified gene.

Although some of the results were shared in the online seminar, they have yet to be published.

The pilot did not yield findings about disease control or managing the wild population of mosquitoes. Instead, at its early stages, it showed researchers that it’s a possibility this method could work.

“I like the way they’re going about it,” Thomas Scott, an entomologist at the University of California, Davis, told Nature. “They’re doing it in a systematic, thoughtful way. So I’m encouraged, but they have a lot of work ahead of them.”

The study was not without criticism.

With another release of mosquitoes in Visalia, Calif., coming up, one activist said the city would become “lab rats” for the company with no input, SF Gate reported.