The first U.S. trial of genetically modified Aedes aegypti mosquitoes to control the population of the insect that transmits diseases such as dengue, Zika and yellow fever begins this week in the Florida Keys.
After more than 10 years of progress and setbacks to get the project approved, the British company Oxitec, which receives funding from the Bill and Melinda Gates Foundation, has begun to place the first boxes with millions of OX5034 mosquito eggs and the first insects, all males, will be flying freely throughout the month of May.
Previously, Florida state authorities and the U.S. Environmental Protection Agency (EPA) gave the go-ahead to the pilot test with the commercially called “Oxitec’s friendly mosquito”, which has aroused the rejection of environmentalists and also of some scientists.
The boxes have been placed in six locations in the chain of islands between the Florida peninsula (USA) and Cuba and less than 12,000 mosquitoes will be released each week for twelve weeks, which means that counting all the waves, some 144,000 “OX5034” mosquitoes will be released.
Three other sites will be tested with traditional mosquito traps to compare results, Oxitec said in a statement.
According to a study prepared by EPA technicians, the Oxitec mosquito “poses no risk to human health or the environment, including protected species.”
Once they are released from the boxes, the genetically modified male mosquitoes will mix with the local population of their species.
But, due to a laboratory-created gene, the females resulting from the crossbreeding of these males with the “natural” females, which are the ones that transmit the diseases, will not be able to survive and thus control the Aedes aegypti population.
Although they make up only 4% of the mosquito population in the Keys, where some 46 species of these insects live, Aedes aegypti are practically the only ones that transmit diseases.
In 2020, coinciding with the Covid-19 pandemic, the Florida Keys saw an outbreak of dengue fever not seen in 10 years, with more than 50 cases, and other outbreaks of West Nile fever, also transmitted by mosquitoes, in different areas of Florida.
The Florida Keys Mosquito Control Council (FKMCD) said in a statement that “new tools” are needed to combat this mosquito species and given the unique ecosystem of the islands it needs to be done in a “safe, environmentally friendly and controlled manner”.
Oxitec’s CEO, Grey Frandsen, said that the pilot test is the result of a public-private partnership and that the company is committed to “demonstrating the value of this technology”.
This is not the first time Oxitec, founded in the UK in 2002, has tested its genetically modified mosquitoes.
In the Brazilian city of Indaiatuba, Oxitec’s mosquito was able to reduce dengue-prone urban environments by up to 95% in just 13 weeks of treatment, compared to places where no mosquitoes were released, the company said.
Republican Congressman Carlos Gimenez, former mayor of Miami, recently announced he was going to ask EPA for further investigation, and the Keys Environmental Coalition has launched several campaigns and initiatives to protest the Oxitec mosquito test and complain that the public was not consulted.
“Once released it will be impossible to contain the numbers of these genetically modified mosquitoes, they will literally be everywhere the wind blows,” said a campaign launched last August on Change.org by the Coalition.