DEET Blocks Mosquitoes’ Ability To Smell; Finding Could Lead to Development of More Effective Repellants, Study Says

DEET, a substance widely used in mosquito repellants, blocks the ability of mosquitoes and other insects to smell humans -- a finding that could help curb the spread of malaria by contributing to the development of more effective repellants -- according to a study published on Friday in the journal Science, Business Day reports. DEET has been used in mosquito repellants for more than 50 years, but until recently, it has been unclear why it prevents mosquitoes from biting humans, according to Business Day. In addition, DEET is not safe for infants and young children -- one of the populations most vulnerable to malaria.

Leslie Vosshall, a molecular neurobiologist from Rockefeller University, and colleagues found that DEET blocks insects' smell mechanism by hindering key odor receptors that rely on a protein called OR83b. By hindering mosquitoes' smell mechanism, DEET masks odors that ordinarily alert mosquitoes to a human presence.

"The only way we can improve on existing technology is to understand how it works," Vosshall said, adding, "Everyone knows DEET is useful, but until now, there has never been a satisfactory explanation of how it works." She added that insect repellants are an important part of malaria control efforts but that new products are needed. "The telephone and television have evolved since the 1950s, but insecticides haven't," she said. The finding could lead to the development of improved mosquito repellants, Vosshall said. "Now we can apply similar tricks the pharmaceutical industry uses to screen millions and millions of molecules to find ones that block OR83b better than DEET," she said (Kahn, Business Day, 3/14).

An abstract of the study is available online.