Update: Genetically Modified Mosquitoes Cause 91% Drop in Dengue Cases in Brazil
Genetically modified (GM) mosquitoes in Brazil have succeeded in reducing dengue cases by 91 percent, officials said.
According to Oxitec, the British biotech company responsible for breeding the genetically modified Aedes aegypti mosquitoes to combat the spread of diseases such as dengue, chikungunya and Zika virus in Brazil, the method has significantly reduced dengue cases from a total of 133 to 12 in the CECAP/Eldorado neighborhood of Piracicaba City from mid-2015 to mid-2016, the company said in a press release.
This is in comparison with majority of the city of Piracicaba that used conventional mosquito-control methods, where dengue cases saw a drop of only 52 percent over the same period.
Oxitec's male GM mosquitoes attack a wild population through romantic deception, where the GM males sire offspring with a built-in self-destruct DNA. This kills off the young in the wild even before they start biting.
According to Science News, this biotech method is a twist in the old strategy for controlling insect population, where sterile males were released in great numbers so that females waste their reproductive efforts, and an entire population eventually breeds itself out of existence.
Oxitec has already released evidence that GM mosquitoes helped reduced mosquito population in certain neighborhoods. But this is the first time the company proved that the GM mosquitoes reduced the spread of the disease.
Brazil, the country most affected by dengue and now Zika virus, is open to using GM mosquitoes in controlling insect population. With its method, Oxitec focused on the CECAP/Eldorado neighborhood of 5,000 residents and where dengue rates were higher than in the rest of the city between 2014 and 2015.
After a year of control measures, including the release of GM mosquitoes, tests showed that the area now fares better than the rest of the city, where dengue incident rate of the area alone dropped to 0.24 percent compared with municipality incidence rate of 0.347 percent.
The Brazilian government has been leading a massive awareness and fumigation campaign to control insect population and the spread of disease-causing viruses.