Female blood-feeding mosquitoes, some species of which can transmit deadly diseases such as malaria and dengue to humans, largely find their human blood meals by detecting carbon dioxide emitted when people exhale. In a new study funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, a research team led by Anandasankar Ray of the University of California, Riverside, identified three types of odor molecules that disrupt the carbon dioxide-sensing machinery of mosquitoes. One molecule switches the mosquitoes' olfactory nerves "on" for prolonged periods, one turns the olfactory nerves "off" and a third type mimics carbon dioxide.
According to the researchers, their finding could lead to a new generation of repellents and lures that might help prevent mosquito-borne human diseases such as yellow fever and West Nile virus as well as malaria and dengue. Experts agree that new mosquito deterrents are needed because the most effective existing repellent, known as DEET, is expensive, impractical in tropical regions and toxic if used inappropriately.