Genetically Modified Mosquitoes Released In US For First Time To Combat Disease

Johannes Van Zijl

Johannes Van Zijl

Johannes has a MSci in Neuroscience from King’s College London and serves as the Managing Director at IFLScience.

Managing Director


This marks the first time that genetically modified mosquitos have been released into the wild in the US. Image Credit: Hans Verburg/

A landmark project, spearheaded by the biotechnology company, Oxitec, has released genetically modified mosquitos in the Florida Keys. This marks the first time that genetically modified mosquitos have been released into the wild in the US. The reason: to combat the Aedes aegypti mosquito species responsible for spreading mosquito-borne diseases such as dengue and Zika in the region.

Aedes aegypti only accounts for about 4 percent of the total mosquito population in Florida keys – however, it is responsible for almost all mosquito-borne diseases to humans. Current methods to control the species, such as spraying or fogging chemical insecticides, have failed due to the species becoming resistant. So an alternative solution was needed.


“Our primary mission is to protect residents in the Florida Keys from all mosquitoes including the disease-transmitting Aedes aegypti. The Florida Keys Mosquito Control District remains committed to seeking out, environmentally-friendly and targeted tools to protect our residents and to preserve our wildlife." Said Andrea Leal, Executive Director Florida Keys Mosquito Control District in a statement.

 “With full approval from the US EPA and the Florida Department of Agriculture and Consumer Services, as well as support from the US Centers for Disease Control and an independent advisory board, we are now eager to see the project progress over the coming months,” Leal added.

The male modified mosquitoes being released by Oxitec are genetically tweaked so that they express a special protein called tTa. Once they mate with wild Aedes aegypti females, the tTa protein is passed on and kills female offspring. By doing so, will suppress the population of wild disease-spreading Aedes aegypti in the area and could therefore reduce the number of transmitted diseases. 

It is key to remember, these genetically tweaked mosquitos do not bite and have already been field-tested in other countries with successThey pose no threat to the environment or to other insects, such as bees and butterflies. Oxitec has acquired all the necessary regulatory approvals for the genetically modified mosquitos to be released at six strategic locations across the Florida Keys in the months to come.


“We’re thankful for the opportunity to demonstrate the effectiveness of Oxitec’s technology with such an outstanding partner. The challenges posed by disease-spreading mosquitoes is growing, not shrinking, making this pilot project a major step forward in bringing Oxitec’s safe, self-limiting technology to the US.” concluded Grey Frandsen, Oxitec’s CEO.


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