Millions of genetically modified mosquitos have been released in the Brazilian city of Piracicaba to combat Dengue Fever.
Created by UK company Oxitec of Abingdon and bred in Brazil, these mosquitoes are designed to crash the local population before they can spread the tropical disease.
The Aedes aegypti male mosquitoes are given a deliberately flawed gene and then released into the wild so that they can reproduce, at which point the implanted gene rears its head and causing offspring to die before they mature.
Plans are to overcome the area with the genetically-modified mosquitoes in order to outnumber native males and eradicate the number of dengue transmitting mosquitoes.
Since April more than six million have been released throughout Piracicaba and earlier local trials have seen a 90% reduction in numbers according to Oxitec.
Brazil polls show high levels of public support for the technique, often seeing more than a million new cases of Dengue Fever a year.
Chief Executive of Oxitec Hadyn Parry said they want to prove it works.
“They’ve asked us to take on the neighbourhood that’s the worst to prove it works,” Parry said. “We hope that if it does, we can expand to a larger number of areas.”
Driving down the native population is what Oxitec aims to do as reducing the disease spreading population by at least 95% should be enough to reduce the numbers of dengue transmitting mosquitoes.
University of Sao Paulo Professor Margareth Capurro told New Scientist the results haven’t been confirmed.
“In theory, if you have fewer mosquitoes you have less transmission, but in reality, this is something we still need to investigate,” Capurro said.
“You can have lots of mosquitoes with only a few infected, or very few with all of them infected. If this happens, you suppress the population but don’t affect dengue transmission.”
Critics have raised objections stating that other mosquito species also carry dengue fever so the disease won’t necessarily be eradicated and fearing will happen if some mosquitoes inherit the modified gene but don’t die from it.
Still, it appears that the risky method is effective enough for the FDA to look into its deployment in Florida as a preventative measure.
Oxitec have further plans to run a trial on an island to see if they can eliminate Dengue Fever using this method.
