Could genetically modified mosquitos prevent mosquito-borne illnesses?
When people think of genetically modified organisms, food crops like GM corn and soybeans usually come to mind. But engineering more complex living things is now possible, and the controversy surrounding genetic modification has now spread to the lowly mosquito, which is being genetically engineered to control mosquito-borne illnesses.
A U.K.-based company, Oxitec, has altered two genes in the Aedes aegypti mosquito so that when modified males breed with wild females, the offspring inherit a lethal gene and die in the larval stage. The state agency that controls mosquitos in the Florida Keys is awaiting approval from the federal government of a trial release of Oxitec’s genetically modified mosquitos to prevent a recurrence of a dengue fever outbreak. But some people in the Keys and elsewhere are up in arms, with more than 155,000 signing a petition opposing the trial of genetically engineered mosquitoes in a small area of 400 households next to Key West.
Many scientists say, however, that genetically modifying the Aedes mosquito — and possibly other types of mosquitoes carrying diseases such as malaria — is a more effective and environmentally benign way of controlling mosquito-borne illnesses than spraying pesticides and other measures. Oxitec’s genetically engineered Aedes aegypti has proven itself in other countries, successfully reducing populations of the insect by up to 90 percent in field trials in the Cayman Islands, Brazil, Malaysia, and Panama. Overall, the trials were so successful that Brazil approved the use of the GM mosquitoes last year.
“Some people don’t want to see GE (genetically engineered) anything,” says entomologist Raymond St. Leger, distinguished university professor at the University of Maryland. “It’s an emotional response. It’s hard to reason people out of a decision they didn’t reason themselves into.”
St. Leger is now conducting field trials in Burkina Faso to test a method in which a mosquito is exposed to a fungus that prevents it from transmitting malaria. He says that Oxitec’s technology to suppress the Aedes aegypti has relatively little environmental risk and that knocking back the mosquito in the Keys, which experienced a dengue outbreak five years ago, “is a matter of urgency.
“You don’t want to wait until it’s endemic,” he says. “The gun is there and cocked and waiting to spread through their mosquitos. The extensive program and spraying with insecticides isn’t working. You need to do something now and not wait until dengue is there. It’s a very dangerous mosquito doing pretty well for itself in Florida.”
Continue reading at Yale Environment 360.
Mosquito image via Shutterstock.