Regulating genetically modified mosquitoes

By Dalia Deak

Fears of spreading zika virus have renewed interest in the use of genetically modified mosquitoes to suppress disease, with recent attention focused on the UK firm Oxitec. Last week, the developing public health crisis around zika prompted the federal government to tentatively clear a small-scale field test for the first time in the United States, pending a public comment process on a draft environmental assessment submitted by Oxitec. It should be noted that a final approval for the trial will not be made until the FDA completes the public comment process.

The genetically modified insects, which are male Aedes aegypti mosquitoes, are designed to breed with the female Aedes aegypti mosquito (primarily responsible for transmitting zika, dengue fever, and other diseases) and contain a gene lethal to their offspring. The female mosquitoes lay eggs but the larvae die well before adulthood. Oxitec claims that recent tests have shown up to a 90% decrease in the population of the Aedes aegypti mosquito, with a recent test in Piracicaba (~100 miles from Sao Paulo in Brazil) showing an 82% decline. Tests have also been conducted in the Cayman Islands and Malaysia.

In the United States, Oxitec is in the process of waiting for FDA approval to conduct trials in the Florida Keys. However, this is relatively unclear and uncharted territory for the federal government in terms of what group should be responsible for the review, and the decision for the CVM jurisdiction in this case remains hotly debated. Jurisdictional debate exists between the U.S. Department of Agriculture and the FDA’s Center for Drug Evaluation and Research (CDER) and Center for Veterinary Medicine (CVM).

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