How mosquitoes are attracted to humans

Washington – Researchers have found that certain mosquito nerve cells, known as cpA neurons, cause mosquitoes to be attracted to humans by detecting exhaled carbon dioxide (CO2) and odors emitted from human skin.

The study by scientists at the University of California, Riverside may have implications for the control of mosquitoes and the diseases they transmit.

By studying Aedes aegypti and Anopheles gambiae mosquitoes, which are key transmitters of dengue and malaria, respectively, the researchers showed that cpA neurons are sensitive detectors of human odors, which in their experiments stimulated mosquitoes to move toward glass beads coated with human foot odor.

In follow-up experiments, the researchers screened more than 440,000 chemicals for those with structures that can interact with the specific proteins on the surface of cpA neurons that detect human odors and CO2.

Of thousands with such a structure, they tested 138 and found several that had previously been recognized as safe for human use and were pleasant-smelling, inexpensive and present in the natural environment.

They pursued two compounds for additional study: ethyl pyruvate, a fruity-scented compound that neutralized cpA neurons’ ability to detect and reduced attraction to human foot odor; and cyclopentanone, a minty-smelling compound that activated the cpA neurons similarly to CO2 and attracted mosquitoes to a trap.

The study was published in the journal Cell.