FDA Gives Initial Clearance for Engineered Mosquitoes

Aedes aegypti mosquito biting a human (U.S. Department of Agriculture)

11 March 2016. The U.S. Food and Drug Administration issued a preliminary report that self-limiting engineered mosquitoes will have no significant environmental impacts on the Florida Keys, where they plan to be tested. The report agrees with an environmental assessment by Oxitec Ltd., developer of the engineered mosquitoes, that the agency is releasing for public comment.

Oxitec, a subsidiary of Intrexon Corporation, plans to field test its Aedes aegypti mosquito variety, code-named OX513A. Oxitec uses genetic engineering techniques to insert a gene in males of the species that when released into the wild mate with females and produce offspring that die before becoming adults, and thus are prevented from having offspring. As a result the Aedes aegypti mosquito population in the area of the release is markedly reduced or eliminated.

The company plans to conduct its field test with the Florida Keys Mosquito Control District. Aedes aegypti mosquitoes are not native to the U.S., nor do they pose an immediate health threat. While the mosquitoes may pose only a nuisance at present, health officials in Florida are concerned about their potential health impact, since the insects are known to transmit dengue, chikungunya, Zika, and yellow fever viruses. Should the field test prove successful, health authorities in the Keys would use many fewer chemical insecticides to control mosquitoes.

The field trial, scheduled to begin after final FDA approval, will release quantities of male engineered mosquitoes three times a week during the test period. The engineered insects and their offspring express a fluorescent protein that allows the company to keep track of the numbers of Oxitec mosquitoes being produced, compared to wild types, through larvae collections.

Oxitec so far conducted field tests of the OX513A variety in the Cayman Islands, Panama, and Brazil. As reported in Science & Enterprise, the tests in Brazil were conducted in the Itaberaba suburb of Juazeiro city in Bahia State, a region known to have a high incidence of dengue disease. The results show the density of Aedes aegypti mosquitoes declined from 418 per hectare to 20 per hectare (1 hectare = 2.47 acres), a reduction of 95 percent, while densities in the adjacent region not receiving the engineered mosquitoes remained about the same over the period.

Oxitec Ltd., in Oxford, U.K., is a spin-off company from Oxford University. In August 2015, the company was acquired by synthetic biology company Intrexon Corp., in Germantown, Maryland, for $160 million.

Read more:

• Zika Virus Genome Sequenced
• Synthetic Biology Company Raises $200 Million in IPO
• Intrexon Acquires Oxitec, Partners on Genetic Disorder
• Genetic Engineered Variety Controls Destructive Moth
• Alliance to Build Photonic Mosquito Control Device

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