A British biotechnology company, Oxitec, is set to release half a billion genetically modified mosquitoes in Florida with the aim of eliminating populations of local mosquitoes, vectors of infectious diseases. The residents are furious and worried.
Islamorada village resident Virginia Donaldson recalls: Two men in uniform showed up at her home in March 2020 and asked her to participate in a new mosquito control program. Pressed for time, and relatively inclined to fight these parasites, she signed the form. She had actually just agreed to participate in a genetic experiment aimed at exterminating the local population of these blood-sucking insects and potential vectors of disease.
Opinions are divided among the inhabitants of the Keys archipelago, where the mosquitoes will be released. Some validate this idea, others fiercely oppose it, not wishing to serve as “guinea pigs” for a genetic hacking experiment, the outcome of which is ultimately uncertain. ” We have everything to risk, nothing to gain, and all this for the results of Oxitec », Indignant Meagan Hull, resident of Islamorada and fervent opponent of the project.
An approach to limit the use of pesticides
The Environmental Protection Agency (EPA) approved Oxitec’s project in May 2020, granting it an experimental use permit – a special permission that allows companies to test new pesticides in the field. The mosquitoes in question have a specific gene, called OX5034, which prevents any female offspring from reaching adulthood. Oxitec claims that these mosquitoes, all males – so they don’t bite humans – will then mate with wild females. They will thus transmit the OX5034 gene to their offspring, the idea being to eventually eradicate all female mosquitoes in the region.
Targeted mosquitoes, of the species Aedes aegypti, make up only 2-4% of the Florida Keys mosquito population, but are important vectors of disease. Oxitec claims that this trial could therefore help stop the spread of diseases such as dengue and Zika, without resorting to dangerous chemical insecticides. This approach also saves other insects, such as bees and butterflies, and preserves the environment.
However, it turns out that the Florida Keys Mosquito Control Board (responsible for controlling local mosquito populations) has no plan to reduce its use of chemical pesticides. So even if the experiment is a success, the sprays will continue to control the myriad of other mosquito species in the region that will not be affected by the genetically modified insects from Oxitec.
Opponents of the project also fear that the transgenic mosquito and the wild population will create genetic hybrids, although Oxitec says the trial is unlikely to permanently alter the mosquito population. The company plans to monitor the population ofAedes aegypti using collecting cups, in order to check the extent to which the modified genome is proliferating. If ever one of the female mosquitoes managed to survive and reproduce, the experiment would take place immediately: ” In the unlikely event that Oxitec identifies genetically modified female offspring, they are required to immediately cease releases, apply conventional pesticides targeting the adult and larval stages of the mosquito, and continue monitoring until no female mosquito. OX5034 not found for two consecutive generations », Specifies Kenneth Labbe, spokesperson for the EPA.
The likelihood of this happening is debated. In a previous experiment, carried out from 2013 to 2015, Oxitec released mosquitoes in Brazil carrying another modified gene, OX513A, and ended up also releasing individuals carrying the modified OX5034 gene. The operation was heralded as a success, but scientists not affiliated with the company warned that some of the mosquitoes had mated, produced viable offspring, and ultimately created a new hybrid population capable of surviving. Nathan Rose, head of regulatory affairs for Oxitec, eventually admitted that some female OX513A mosquitoes had survived in Brazil, but he was convinced that the OX5034 mosquitoes could not. For the EPA, there is a “negligible” potential for survival of female OX5034 during this new field trial of Oxitec.
A lack of transparency that does not create confidence
Today, a large coalition of environmental activists, academics and Key West residents have come together to oppose the experiment, at least in its current form. But, unless you leave the area permanently, it is difficult to withdraw from the project if other residents continue to participate. The question of informed consent does not even come into play, as the experiment does not meet the regulatory definition of research involving human subjects. ” Oxitec does not test on humans and this project does not introduce any risk to humans, animals or the environment, as stated by the EPA », Confirms Nathan Rose.
The issue of consent and the lack of transparency – much of the regulatory process was inaccessible during public consultation – largely motivated opposition from residents and activists. Among them, Dana Perls, head of an environmental group called Friends of the Earth, which calls for independent testing to certify that Oxitec’s products are safe. ” For community members who are going to be on the front lines of one of the first massive releases of GMO insects in the United States, […] it’s a matter of health, safety and the environment “, she says.
Perls points to the fact that the EPA never asked Oxitec to do cage trials prior to large-scale release. Just as new pharmaceuticals are tested on cultured cells and then on animals to ensure they are safe for humans, a caged release would reveal any potential problem or danger associated with the procedure. ” At a time in history when biodiversity is more devastated than it has ever been, when we are in the midst of a global public health crisis, we must focus on scientific evidence », Emphasizes Perls. But for Oxitec, preliminary cage tests are not necessary given the absence of risk for humans or the environment and would above all be irrelevant for the evaluation of the process.
The experiment should last 18 months. Oxitec mosquito eggs will be delivered to residents in the form of “just-add-water” kits; they will include both females and males. According to the company, around 1,000 males are expected to hatch from each kit in two weeks. Females carrying the gene are believed to be unable to survive without tetracycline and therefore would have to die as larvae; the problem is that tetracycline is commonly used as an agricultural antibiotic in citrus groves in the region. As a result, the EPA has prohibited Oxitec from releasing mosquitoes within 500 meters of any location where tetracycline is used. But at no time did the EPA require that the water at the release site be tested for traces of this compound …
Nor did the EPA permit require an assessment of whether this intervention actually resulted in reduced disease transmission or whether the introduction of an already invasive species would have unexpected effects on the ecosystem. ” There is no scientific data reviewed by an independent third party, there are no safety studies, there is no environmental impact study », Underlines Meagan Hull, co-founder of the Florida Keys Environmental Coalition born out of the Deepwater Horizon oil disaster.
Note also that male mosquitoes are also capable of spreading disease. They do not bite humans, but can infect (or be infected by) the females they mate with. By releasing millions of individuals, it is therefore possible to increase the population of females carrying a virus and thus increase the prevalence of diseases in the region. ” It is not too late. EPA should press the pause button, and since this could be the first release of genetically modified insects on this scale, we need to do it right. Dana Perls concludes.