Study suggests ways to stymie mosquitoes' human-detection system
California researchers say they have determined that a mosquito neuron that detects human breath also detects human skin odors, and they report the discovery of two compounds that may reduce the insects' ability to zero in on humans.
A neuron called cpA enables mosquitoes to detect carbon dioxide from human breath, according to the researchers' report in Cell and a press release from the University of California, Riverside (UCR). UCR scientists determined that in two mosquito species that spread dengue virus and malaria, this same neuron is also a sensitive detector of human skin odors.
When the researchers chemically inactivated cpA, they found that the mosquitoes' attraction to glass beads coated with human foot odorants was reduced, according to a press release from the National Institute of Allergy and Infectious Diseases (NIAID), which sponsored the study.
The scientists also screened more than 440,000 chemicals for ones that can interact with cpA neurons, the NIAID said. They tested 138 compounds and found several that had previously been recognized as safe for human use and were pleasant-smelling, inexpensive, and present in the environment.
They homed in on two compounds for additional study: ethyl pyruvate, a fruity-scented cpA inhibitor approved as a flavor agent in food, and cyclopentanone, a minty-smelling cpA activator approved as a flavor and fragrance agent, according to UCR. The scientists found that ethyl pyruvate substantially reduced the mosquitoes' attraction to a human arm, and that cyclopentanone strongly attracted mosquitoes to a trap.
"Such compounds can play a significant role in the control of mosquito-borne diseases and open up very realistic possibilities of developing ways to use simple, natural, affordable, and pleasant odors to prevent mosquitoes from finding humans," said Anandasankar Ray, PhD, an associate professor at UCR and the project's principal investigator.
Dec 5 Cell abstract
Dec 5 UCR press release
Dec 5 NIAID press release
Red Cross/Crescent announces cholera plan for Hispaniola
The International Federation of Red Cross and Red Crescent Societies (IFRC) yesterday announced a new plan for combatting cholera in Haiti and the Dominican Republic, the two nations that compose the island of Hispaniola, the agency said in a news release.
The plan is a response from appeals to Red Cross groups in both nations, and the IFRC seeks $12.6 million to fund it. The plan aims to assist 60,000 people in each country for 2 years with cholera relief efforts. It is part of the countries' health ministries' 10-year plans to address the situation.
Haiti has seen almost 700,000 cholera cases and more than 8,300 deaths since its outbreak began in October 2010, according to data from the US Centers for Disease Control and Prevention. The Dominican Republic has confirmed more than 30,000 cases and more than 400 deaths since November 2010, according to Pan American Health Organization statistics.
IFRC efforts will include supporting treatment centers, bolstering water and sanitation systems, supporting cholera patients, and educating people on hygiene.
"Given the continued spikes in cholera, the operation will be conducted with a flexible approach that balances the commitment and need to improve the infrastructure while simultaneously responding to local spikes in cholera," the IFRC said in its report on the plan.
Dec 5 IFRC news release
Dec 5 IFRC report on the plan
