Biotech company Oxitec has spent years trying to gain approval to release its controversial genetically modified (GE) mosquitoes in the US, especially in Key West, Florida. In June 2020, the Florida Department of Agriculture and Consumer Services launched the plan,first after the US EPA issued an experimental use permit (EUP) allowing GE mosquitoes to be released in Florida as well as Texas.2
April 2021 marks the culmination of Oxitec’s efforts, when nearly 5 million GE Aedes aegypti mosquitoes were released in the Keys over a seven-month period.3 – despite backlash from residents and environmental groups. In March 2022, EPA gave Oxitec a two-year extension to its EUP,4 this will allow Oxitec to release more GE mosquitoes in Florida as well as release GE insects for the first time in four California counties.
The EPA’s extension to Oxitec’s EUP paves the way for 2.45 billion GE mosquitoes to be released – an extension that was granted even before Oxitec publicly released results from the 2021 field test release in Florida.5
What is GE Mosquito?
The mosquito species Aedes aegypti, (A. aegypti), carries yellow fever, dengue, chikungunya, Zika, West Nile and Mayaro,6 a disease resembling dengue fever. (Malaria is transmitted by another type of mosquito, Anopheles.)7 Oxitec created GE mosquitoes in an effort to control mosquito-borne diseases such as yellow fever, dengue, chikungunya, and Zika, although it is not known whether they will work for this purpose.
Male A. aegypti mosquitoes have been genetically engineered to carry a “gene kill switch,” so that when they mate with wild female mosquitoes, their offspring inherit the lethal gene and are unable to survive or reproduce in the wild. course. In the United States, Oxitec is marketing the insects as Oxitec Friendly™ mosquitoes and explains:8
“After releasing Friendly™ males into the field, which they find and mate with wild female mosquitoes, the target population reduction will be achieved because the females of these encounters cannot survive. The female survives, carrying one copy of the self-limiting gene; In turn, these males were able to pass the self-limiting gene to half of their offspring, of which females carrying the gene were unable to survive.
Thus, the self-limiting gene may persist but decline over time, providing multiple generations of potential but still self-limiting repressors for each Oxitec Friendly™ Aedes aegypti male released. ”
The US FDA, which had previously reviewed GE mosquitoes, initially stated that GE mosquitoes would not have a significant impact on the environment, but was reportedly interested in how the “gene kill switch” would work as like in nature and whether it could be humans or other animals.9
In October 2017, the FDA then transferred regulatory approval to the EPA, after apparently classifying GE mosquitoes as pesticides rather than drugs to prevent disease.ten The transfer is a big win for Oxitec, as the EPA is required to quickly review new pesticides, within 12 months of submission, while the FDA doesn’t have a set deadline.
After handing it over to the EPA, Oxitec wasted no time in resubmitting a request to release mosquitoes in Florida, as well as Texas — and it was approved by the EPA — but residents protested the release of GE insects into the local environment. their. In addition to Florida, Oxitec’s GE mosquitoes have previously been released in the Cayman Islands, Malaysia, Panama and Brazil.11
EPA ignores possible health and environmental impacts
The Florida Department of Agriculture and Consumer Services (FDACS) approved the EPA’s expansion of Oxitec’s field testing despite the unknown risks posed by GE mosquitoes. This has sparked a backlash from environmental groups and scientists. Jaydee Hanson, policy director at the Center for Food Safety, told Sustainable Pulse:twelfth
“FDACS should have asked Oxitec to stop claiming as ‘confidential business information’ their data on human health and the environmental impact of mosquito releases. In Spain, when Oxitec withheld the data, the Spanish government requested that Oxitec publicly disclose the safety impacts on health and the environment of their genetically modified insects.
Florida should have done the same. Furthermore, FDACS should not have allowed a second release without making data from the first trial publicly available and asking for a review by unbiased scientists in the field. ”
Barry Wray, director of the Florida Keys Environmental Coalition, echoed these concerns, particularly regarding the EPA’s lack of concern for the public:13
“We should all be extremely concerned about an EPA forgetting the middle name, the protection, with this approval. Public trust is abused by Oxitec’s lack of scientific transparency and no independent scientific investigation from the EPA to show that this experimental insect won’t create more problems. Is it going to solve… The release of these mosquitoes is morally abominable.”
Brazil trial shows GE gene escaped to the wild
Oxitec’s previous trials have been cited, including the release of Oxitec’s GE mosquito, known as OX513A, which occurred in Jacobina, Bahia, Brazil. About 450,000 male mosquitoes have been released weekly for 27 months in the area to reduce the number of disease-carrying mosquitoes.14
The researchers wrote in the journal Scientific Reports: “If complete eradication, the release of this strain would only reduce population size and not affect the genetics of the target populations.15
However, this is not the case. Yale University researchers monitored populations of A. Aegypti mosquitoes in Jacobina to determine whether the release of GE mosquitoes affected the genetics of wild populations by gene transfer. The GE mosquito contains a fluorescent protein gene, which allows the detection of GE offspring.
In analyzing six, 12, and 27 to 30 months after release, the researchers found “clear evidence that portions of the genome of the transgenic strain were integrated into the target population.”16 Research explains:17
“It is clear that these rare crosses between the released line and the Jacobina population are healthy enough to be able to reproduce in the wild. The released strain was developed using a line originally from Cuba, which was then outcrossed with the Mexican population.
So, Jacobina Ae. aegypti is now a combination of three populations. It is unclear how this might affect disease transmission or affect other efforts to control these dangerous vectors.”
A triple population of GE mosquitoes currently exists in Jacobina (Cuba/Mexico/Brazil). Due to their distinct genetic characteristics, the study found, populations are likely to be “healthier” than they were before the release of GE mosquitoes due to “hybrid vigor”.18
Oxitec releases webinar on field test data
In April 2022, after the EPA expanded Oxitec’s EUP, the company presented a webinar on results from an outdoor mosquito trial in Florida. To conduct the study, boxes of GE mosquito eggs were placed in private houses, surrounded by traps. Male GE mosquitoes hatch and circulate in an area, within a hectare (2.47 acres) similar to the range of wild mosquitoes.
After the mosquitoes mated and the wild females laid their eggs in the trap, the researchers collected about 22,000 of them and brought them to the lab for incubation. Females with inherited GE genes were identified because they fluoresce under laboratory light.19
Oxitec states that all women who inherit the GE gene die before adulthood, and that the gene is no longer found in wild mosquitoes after a few generations.20 They also noted that no GE mosquitoes were found to have traveled further than 400 meters (437.4 yards) of the drop site.21
However, the pilot study did not reveal whether releasing GE mosquitoes suppressed wild populations or, importantly, whether it reduced transmission of diseases carried by A. aegypti. Thomas Scott, an entomologist at the University of California, Davis, made an interesting point when he told Nature, “They won’t be able to do a test to prove that it actually has an impact on health. community health. There are not enough cases of the virus transmitted by Aedes in the Florida Keys. ”22
If Aedes disease rates in Florida are so low, why release GE insects in the first place? According to the CDC:
- Dengue fever – “Nearly all dengue cases reported in the 48 contiguous US states have been in travelers infected elsewhere”.23
- Chikungunya – From 2016 to 2020, there were no cases of locally acquired chikungunya virus in the United States24
- Eastern equine encephalitis virus (EEEV) – “Only a few cases are reported in the United States each year.”25
- Zika Virus – From 2018 to 2020, no local cases have been reported.26
Furthermore, according to Scott, even very low populations of A. aegypti can lead to disease outbreaks, so even if Oxitec’s GE mosquito is successful in reducing local populations, it may not migrate disease is reduced. “It’s not that simple,” he said.27 One more question about the need for GE mosquitoes, A. aegypti accounts for only about 4% of mosquitoes in the Florida Keys.
“The black salt marsh mosquito (Aedes taeniorhynchus) – a nuisance rather than a vector – probably represents about 80 percent of the mosquito population on the archipelago,” according to Nature, which means the release of GE mosquitoes. Nor will it reduce the need for pesticides.28
Releasing GE mosquitoes into the wild is a bad idea
Residents have every right to be concerned about releasing GE insects in their backyard, as the results of this reckless experiment remain completely unknown and the EPA has not been transparent about its analysis of the data. According to Sustainable Pulse:29
“Unfortunately, the EPA has not publicly shared its entire public health analysis, and allergenicity and toxicity data have been re-gathered from public documents. The EPA’s critical environmental assessments are also inadequate and do not mandate scientific trials using cage tests prior to release.
Dana Perls, director of the emerging technology program at Friends of the Earth, expressed further disappointment at the EPA prioritizing business interests over public health:30
“Science done poorly, secrecy and lack of transparency is once again being ignored by government officials and the voices of the scientists involved and those most affected. First in Brazil, and now in Florida, government agencies have ignored the mark and promoted the interests of a private corporation over public health and ecosystem protection.”
Mosquitoes can certainly transmit disease, so while it is dangerous and wrong to release GE mosquitoes, it is wise to take reasonable steps to avoid being bitten. You can do this by:
- Wear long sleeves and long pants if you know you’ll be outdoors in an area prone to mosquito bites
- Use natural insect repellents (not synthetic chemical versions), such as cinnamon leaf oil, lemongrass essential oil, or catnip essential oil, if necessary
- Use a home fan in your backyard to keep mosquitoes away when you’re outdoors, Strategies for growing marigolds, which mosquitoes tend to keep away
- Drain standing water, including pet bowls, gutters, trash and recycling bins, spare tires, birdbaths and children’s toys, as this is where mosquitoes breed
- Install a bat house, because mosquitoes are one of their favorite meals
