The use of transgenic, genetically modified mosquitoes, to eliminate diseases such as malaria or dengue, does not show conclusive results. However, millions of dollars are invested in a technology whose effects on biodiversity and ecosystems are unknown. What is the reason?
In April 2022, researchers from the British biotechnology company Oxitec claimed to have completed the first outdoor study in the Florida Keys, in the United States, with genetically modified mosquitoes of the species. Aedes aegypti, produced by this company.
Five million of these mosquitoes were released in these keys for almost eight months, with the main objective of observing how the natural populations of the Aedes aegypti, transmitting agent of dengue, zika, yellow fever and chikungunya viruses.
According to Oxitec’s technology, the modified males carry a lethal gene (OX5034) which, when released into the environment and after mating with wild females, causes the female offspring to die before reaching the capacity to reproduce, while the male will continue to reproduce. carry the gene and continue to pass it on. With these preliminary results, which the company qualified as positive, they hope to carry out more tests and obtain more authorizations to continue demonstrating the effectiveness and safety of their method.
Background on the release of transgenic mosquitoes
Almost three years earlier, in August 2019, the Gorgas Memorial Institute for Health Studies, a Panamanian research institution that was under US control until 1990, stated that by releasing more than 4 million Oxitec mosquitoes (OX513A), between May and November 2014 in the city of Nuevo Chorrillo, managed to reduce the natural population of Aedes aegypti by 93%. Despite the optimistic reports of the Institute’s scientists on the results obtained and the cost of the study carried out (more than 700 thousand dollars), no evidence was found that, in Panama, the use of this substance is being considered. the national strategy to combat dengue and other diseases transmitted by the Aedes aegypti.
A recent review of the website of the Ministry of Health of Panama does not show anywhere that the behavior of genetically modified mosquitoes has already been evaluated, while at the Gorgas Institute all information has been withdrawn or deactivated, so it is not known if they were subsequently monitored the areas where these insects were released, in case there were females with the introduced gene reproducing freely; and, what would be worse: capable of producing dengue. The great enthusiasm and optimism that this technology aroused in some Panamanian scientists in 2014 has dissipated like soap bubbles.
Between 2013 and 2015, a test similar to the one developed in Panama had already been carried out in Juazeiro, a Brazilian municipality in Bahia. There, a 90% reduction in the mosquito population was reported. Aedes, which again increased significantly a year and a half after the test was carried out; Noting, moreover, not only that the genetic modification was transferred to mosquitoes from the wild population, but that the test itself produced no effect on dengue as a disease. Despite this, in 2020 the Brazilian biosafety authority approved the commercial use of transgenic mosquitoes throughout Brazil. Today, Oxitec claims to have released more than one billion GM mosquitoes worldwide, including the Cayman Islands, Malaysia, four counties in California, Yucatan, Mexico and other countries.
The effectiveness of transgenic mosquitoes has not been proven
The truth is that in all places and countries where tests have been carried out to control the natural populations of the Aedes aegypti, Based on the release of genetically modified mosquitoes, it has not been possible to demonstrate that this method is as effective and safe as its creators promised. The flaws in the technology found show that nothing prevents the modified mosquitoes from interbreeding with other species such as the Aedes albopictus (which is more invasive and lethal than the species aegypti), are more resistant to insecticides after that, or have a greater capacity to cause more serious disease.
Already in 2018 in the article “Dengue and the lie of transgenics”, when referring to the main problems of the method of the company Oxitec to fight the aedes aegypti, I expressed the following:
“So far, there is no doubt that one of the major problems with Oxitec’s technology, and any other similar technology, is that, as a result of the serious shortcomings, insecurities and risks it entails, modified mosquitoes end up being imposed on nature. , with all the uncertainties and unknown environmental impacts that this represents. This situation, possible in the real world, is based on the fact that the RIDL technique uses in the laboratory a method of separation by size in the pupal stage of transgenic males and females, so ineffective that for every half a million male transgenic mosquitoes produced, filtered and released, along with them, a maximum of more than 100 females”.
The relationship with the antibiotic tetracycline
Later, when describing this technique and its relation to the antibiotic tetracycline, I stated:
“Another important problem that characterizes the technology of transgenic mosquitoes is the dependence on an antibiotic as common in the environment as tetracycline; It is widely used in human and veterinary medicine and in industrial agriculture, which is why it is usually found in urban waste, fast food, soil, sewage and dog and cat food, among others. This medicine, which in the Oxitec laboratory is used to create transgenic mosquitoes until their adult stage, if there are no descendants later, assure the creators of the technology, it condemns them to die in a programmed way.
However, at the same time, they admit that, under controlled laboratory conditions, they observed that up to 3% of mosquitoes survived without tetracycline and that between 15-18% also did, when they found this antibiotic both in natural environments and in some foods. Therefore, it is easy to deduce that this survival rate will be much higher if, along with the transgenic mosquitoes that can survive without the antibiotic, we add those that are released in areas where tetracycline is listed as an important industrial pollutant. “.
Technological deficiencies and ethical issues
Due to these evident deficiencies that, since its appearance, the transgenic technology of mosquitoes from the Oxitec company has been presenting, as well as to the constant questions that its releases in the environment produce everywhere, the biotechnological companies began to believe that the solution to all of these problems lie in the use of genetic units.
In 2015, using the CRISPR/Cas9 tool, female mosquitoes of the genus anopheles gambiae that transmit malaria, inserting genes that prevent the growth of the hemoparasite of the genus Plasmodium, causing this disease. Three years later, scientists at Imperial College London reported in the journal Nature Biotechnology that, using genes, they created a genetic mutation that made female mosquitoes sterile. anophelesand that in just eleven generations they successfully eliminated an entire isolated population of this insect for the first time.
So a technology designed to wipe out entire populations of living things seems commercially more attractive for dealing with mosquitoes that cause disease in humans. But this time it’s not just about regulating them over time, but quickly and forever extinguishing them as a species, regardless of biosecurity risks and ecological consequences for ecosystems. The lack of ethics of the defenders of this method is of such magnitude that they dare to affirm that “It is one of the most respectful of biodiversity for mosquito control”.
Conclusions on transgenic mosquitoes
We already know that enthusiasts of technologies like these and those who are very interested in commercializing them for the enormous economic benefits that are expected, tend to ignore or minimize the concerns they cause, as well as the risks and potential impacts they generate. The technology of transgenic mosquitoes seems destined to create more problems than solutions in the ecosystems involved. Therefore, there is no doubt that it poses a real threat to the entire environment, human health, food security and wildlife.