The Florida Keys Mosquito Control District is having a town hall meeting tonight about a plan to release genetically modified mosquitoes in order to control the population of Aedes aegypti, the mosquito responsible for the spread of dengue fever.
While the company behind the plan, Oxitec, insists the plant is "environment-friendly," that genetic modification is "a well-understood, safe technology" and that there would be "no permanent change to the wild mosquito population," environmental groups say the plan is "dangerously misguided" and that the company has hidden the fact that the genetically modified mosquitoes could have high survival rate in wild.
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From Oxitec's Q&A for Key West (pdf):
What exactly is the Sterile Insect Technique (“SIT”)?
The Sterile Insect Technique (SIT) is an environment-friendly, species-specific method of insect control, which has been described as “birth control for insects” SIT has been used very successfully in agriculture for over 50 years.
SIT works by releasing sterile insects of a target species. The sterile males compete with the wild males for female insects. If a female mates with a sterile male then it will have no offspring, thus reducing the next generation's population. Repeated release of insects can eventually reduce the insect population to very low levels or zero and hence reduce the damage or spread of disease.
Is Oxitec’s mosquito genetically modified?
Is genetic modification inherently bad or dangerous?
No. Genetic modification allows scientists to combine genes or DNA segments in a precise and calculated manner, to achieve a desired outcome: it is a well-understood, safe technology and there is nothing inherently dangerous about the process. This combining, or recombining of DNA segments leads to another name for the same technique – recombinant DNA technology and hence recombinant insulin, recombinant vaccines, etc; genetic engineering is another. GM/recombinant/GE approaches are regularly used, for example, in the production of pharmaceutical drugs or vaccines, new medical approaches (gene therapy) in industry (production of enzymes) and in new biofuel approaches.
- It is an environmentally friendly approach. No toxic chemicals are used in our approach. The sterile mosquitoes released will only mate with their own species; so off-target effects are minimised; this is far better specificity than an insecticide. “Off-target effects” are effects on species other than the intended target, in this case Aedes aegypti; in other contexts this might be called collateral damage. The potential indirect effects, e.g. the ecological consequences of successfully suppressing the target population, appear minimal and are discussed further below.
What are the likely impacts on the environment and on humans?
The main impact on human health will be to reduce the number of Aedes aegypti mosquitoes that can spread dengue.
There is no permanent change to the wild mosquito population and therefore unlikely to have any impact on the environment compared to the currently used alternatives.
Once the sterilised mosquitoes have mated with the wild female Aedes aegypti mosquitoes, what happens to them? Do they just die off?
Yes. Aedes aegypti is a relatively short-living species. Adult males can live up to around 10 days in the wild. In the laboratory, under ideal conditions, they can live a bit longer, even in extreme cases only up to a month.
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“We cannot stress strongly enough how dangerously misguided this application is. Oxitec hopes to use the neighborhoods and precious ecosystem of the Keys as their private, for-profit laboratory. The shame of it is, the company has no evidence the GE mosquitoes will even work in their stated aim of controlling Dengue fever. This feels much more like Oxitec testing its living, breeding technology than a serious attempt to control disease, and the people of Florida deserve protection.
“The Max Planck Institute for Evolutionary Biology in Germany said in February that the ‘risk assessment’ conducted in advance of the release of Oxitec’s GE mosquitoes in another country has been ‘scientifically deficient’ and made ‘questionable pivotal scientific assertion[s]’. This is simply not good enough, and we strongly urge the Food and Drug Administration to decline the application.
“We are also aware that Oxitec is hoping to conduct a similar outdoor experiment in the UK next year with their GE version of the diamondback moth, which attacks crops like cabbage, broccoli, cauliflower and rapeseed (canola). What impacts will such an experiment have on the birds that eat the moth? What happens to people if they inadvertently eat eggs this GE insect lays on the crop? How will they get the insects back if something goes wrong?
“There are better, safer ways to control Dengue and agricultural pests – we don’t need expensive GE insects. Oxitec badly needs FDA approval to keep their finances flowing. This is why the company downplays any concerns raised, but those concerns are still there and growing with time. The Federal Government must step in and prevent this unnecessary and risky trial.”
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A confidential internal document obtained by civil society groups shows genetically modified mosquitoes described by their manufacturer, UK company Oxitec, as “sterile” are in fact not sterile and their offspring have a 15 percent survival rate in the presence of the common antibiotic tetracycline.
Eric Hoffman of Friends of the Earth U.S. said: “The fact that Oxitec is hiding data from the public has undermined its credibility. Oxitec’s assertions cannot be trusted. Trials of its mosquitoes must not move forward in the absence of comprehensive and impartial reviews of the environmental, human health and ethical risks. Such trials must also await the establishment of a clear and well designed regulatory framework, which does not yet exist.”