Scientists alter mosquitoes’ genes to stem disease spread

By Laura Mize • Published: May 7th, 2010
Category: Health in a Heartbeat

If your summer vacation plans include a trip overseas, you may have heard of dengue [den-gee (‘g’ like ‘gorilla’].

A disease characterized by extreme head and muscle pain, a rash and fever, dengue is very common in Africa and southeast Asia and is spread by the Aedis aegypti [ay-EE-deez ee-JIP-ty] mosquito. These mosquitoes also live in some areas of the southern United States, though the disease is rare in the U.S.

No vaccines or medicines exist specifically to fight dengue. Mosquito netting over beds, a common tool used to combat mosquito-borne diseases, is not effective against dengue because the mosquito that spreads it is active during the day.

Scientists writing in the Proceedings of the National Association of Scientists say they’ve found a new way to stem the spread of dengue. It’s all in the mosquitoes’ genes.

The researchers altered the genes of male Aedis aegypti mosquitoes so any female offspring they produced would be unable to fly. Dengue is spread only by female mosquitoes.

After the altered mosquitoes mated, their female babies were indeed flightless. Without flight, the scientists say the females will not be able to mate or search for food in the wild and will die without reproducing. They say releasing large numbers of eggs containing the genetically altered males into the wild could help diminish the population of dengue-carrying mosquitoes.

The World Health Organization says prevalence of dengue has increased significantly in the past several decades, and two-point-five-billion people are at risk. By tinkering with these mosquitoes’ genes, scientists may have found an effective tool against this problematic disease… one that could make Africa and Asia safer places to visit.