A growing threat of mosquito-born diseases, such as Dengue Fever and Chikungunya, among US population is calling for some drastic measures. Other parts of the world are affected as well. Some 390 million people get infected with Dengue virus each year. Mosquito controllers are exhausting available options for this problem. Two species of mosquito, Aedes aegypti and Aedes albopictus, the main vectors of those diseases, have developed resistance to most of the insecticides used for their treatment.
Dengue, also known as breakbone fever, can cause a number of symptoms which include fever, acute pain, nausea and a skin rash. In some cases it can even develop into the serious illnesses, known as dengue hemorrhagic fever and dengue shock syndrome, which can have a fatal outcome. For now, there is neither preventative vaccine nor treatment for either one of the diseases, but medications help reduce some of the symptoms. The same applies to Chikunguya disease.
British biotech company Oxitec, which specializes in controlling harmful insects, offered a promising solution to the outbreak of dengue in the form of genetically modified male specimens of Aedes aegypti. Males of Aedes aegypti don’t bite, so the modified specimens shouldn’t present any threat to other living beings, except for the offspring of their own species. Through the natural process of reproduction, these mosquitoes would pass two additional genes to the new generation and cause them to die before reaching the stage of fully developed adult, capable of biting. Previous trials confirmed the effectiveness of Oxitec’s solution, since the Aedes aegypti population was substantially reduced in treated areas, up to 96%. Currently, there are some 70 million of Oxitec’s mosquitoes distributed in several countries. Because of the low production and shipping costs of GM mosquitoes, this method of dealing with the parasite-infected insects could be a promising alternative to the use of insecticides. Additionally, Oxitec researchers might be on the trail of discovering a similar solution for malaria, the mosquito-born disease responsible for 627, 000 deaths every year.
Making these insects kill themselves seems like a brilliant idea. But, are there any risks related to the potential transfer of the synthetic DNA from these new creatures to humans? Oxitec claims that among the population of their RIDL ® (Release of Insects With Dominant Lethality) mosquitoes there can be less than 0.1% of females, and that the risk of humans getting bitten by these GM mosquitoes are remote. However, even in such a case, they claim, there is no evidence suggesting that new proteins would be harmful to humans, since they possess no toxic or allergenic properties. Last year, Oxitec got the approval from the Brasil’s National Technical Commission for Biosecurity (CTNBio) for a commercial use of their GM mosquitoes. Now, they are hoping to get the green light from the FDA to release their mosquitoes in Florida Keys this spring, but the Change.org has launched a petition to ban this experiment.