Genetically modified mosquitoes designed to limit the spread of the Zika virus will likely soon be unleashed in the southern United States, as the federal government said today decided to permit a field test in the Florida Keys.

The Food and Drug Administration (FDA) said it had made a preliminary determination that the GM mosquitoes are unlikely to harm humans, animals, or the environment.

The agency’s Center for Veterinary Medicine said it found no significant impact for the trial of a method intended to reduce populations of the Aedes aegypti mosquito that spreads Zika, as well as chikungunya, and dengue among humans. The Florida Keys Mosquito Control District wants to conduct a trial of the mosquitoes, proposed by the British biotech firm Oxitec, in a small neighborhood north of Key West. [1]

Oxitec’s GM mosquitoes have already been released in South America, where Zika is expected to sicken an estimated 4 million people by the end of 2016.

The New York Times explains how it works:

“The mosquitoes, developed by a British company, Oxitec, contain a gene that kills the insect. Male mosquitoes containing the gene are released to mate with wild females. Offspring from such matings die before they reach adulthood, and in that way suppress the population of wild mosquitoes that can spread diseases like Zika and dengue fever.”

The offspring are born with a fluorescent marker gene which allows inspectors to identify larvae when they conduct mosquito counts and gauge the progress of the program.

The Zika virus has been linked to microcephaly, a birth defect which causes babies to born with an abnormally small head and brain. A study released Wednesday finds that women who become infected with the virus during their first trimester of pregnancy may have an increased risk for having a child with microcephaly. [2]

And while most people easily recover from Zika, the virus can cause serious brain infections in adults, including Guillain-Barre syndrome, which can temporarily paralyze patients and leave them with permanent muscle weakness; meningoencephalitis, an inflammation of the brain and its membrane; and myelitis, an inflammation of the spinal cord which can also leave patients with paralysis. [3]

Navy Medicine Zika Infographic v4
Source: Military Health System

So, there is reason to be concerned about the spread of the Zika virus, but there’s also reason to be concerned about releasing GM mosquitoes into the sky. Experts are concerned that trying to eradicate an entire species from the planet could devastate the global ecosystem.

Read: As the Zika Virus Spreads, Genetically Modified Mosquitoes Become More Real

Last month, the day after President Obama requested 1.9$ billion in funds to fight Zika, a panel of epidemiologists, global policy experts, sociologists, and geneticists questioned the ethics of letting scientists “play God” by altering the genetic makeup of creatures in the wild.

Kevin Esvelt, a genetic researcher at MIT’s Media Lab, said:

“It is not something that we should do lightly — to deliberately alter the traits of a wild population. Even with something like a mosquito, which most of us are probably not very fond of, there might be unexpected ecological side effects.”

The concern is that the altered genes could be passed on from generation to generation of mosquitoes (the typical lifespan is 1 month), and eventually extend to the entire mosquito population. 

Eleonore Pauwels, a member of the Science and Technology Innovation Program at the Woodrow Wilson International Center for Scholars in Washington, D.C. explained why this sounds like the perfect solution, but it’s actually quite dangerous:

“We now have the power to hijack evolution. Many people think it’ll be efficient and predictable. But that’s not the case here. We need to know how to talk about to the public, so they understand the risks.”

In the wrong hands, the technology could be used as a biological weapon of mass destruction capable of causing irreversible damage to the human gene pool. [4]

Oxitec has, itself, admitted that a small number of its mutant mosquitoes – including biting females – can survive past the larval stage, and introducing any new engineered species into the wild brings up the possibility that humans may be allergic to it. [5]

As you can imagine, some Florida residents are vehemently opposed to the experiment. Said Mila de Mier, a vocal opponent of the GMO mosquito:

“Less than a mile from the release site is a senior center and a local school. That area was not one that was affected by dengue. Not a single case ever. So why does the FDA want to do an experiment here when they can do this all over the world?”

Mila de Miertold CNN:

“People don’t want to be guinea pigs. There has been no acceptance from community members. If the local and federal government fail to protect us and our wishes, our last option will be to trust the judicial system and bring it to the court. A legal battle is an option at this point.”

The FDA has given the public 30 days to comment on the experiment. After that, the agency will issue its final decision. If approved, the GM mosquitoes could be released into the wild shortly thereafter. 


[1] The Seattle Times

[2] The Verge

[3] Business Standard

[4] ThinkProgress

[5] Mother Jones

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About Julie Fidler:
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Julie Fidler is a freelance writer, legal blogger, and the author of Adventures in Holy Matrimony: For Better or the Absolute Worst. She lives in Pennsylvania with her husband and two ridiculously spoiled cats. She occasionally pontificates on her blog.