Gene-modded mosquitoes will fight Dengue Fever in Brazil

The Brazilian city of Piracicaba has a potent new weapon in the ongoing fight against Dengue Fever, which infects more than a million people annually: genetically modified mosquito lotharios Created by Oxitec of Abingdon, UK and bred locally within Brazil, these GM mosquitoes (all of which are male) are designed to crash the local population before they can spread the tropical disease. More than six million have been released throughout Piracicaba since April. When a GM male mates with a wild female, his sapper genetics cause the resulting larvae to die before they can reach adulthood. What's more, the larvae also carry a genetic mutation that causes them to glow red under UV light, giving researchers an easy way to identify them on sight. "It gives an instant readout of how successfully you're driving down the native population," Hadyn Parry, chief executive of Oxitec, told New Scientist.

And driving down the native population is exactly what Oxitec is trying to do. Reducing the disease-spreading population by at least 95 percent should be enough to prevent its spread. However, that result hasn't yet been confirmed. "In theory, if you have fewer mosquitoes you have less transmission, but in reality, this is something we still need to investigate," Margareth Capurro of the University of Sao Paulo, told New Scientist. "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."

Still, the method appears effective enough for the FDA to look into its deployment as a preventative measure in Florida. The agency has already completed its initial review and will open its findings to public comment prior to making a final decision. Oxitec recently published its study in PLOS: Neglected Tropical Diseases.

[Image Credit: Arnulfo Franco/Associated Press]