Electronic Mosquito Repellant Devices Do Not Prevent Spread of Malaria, Study Says

Electronic mosquito repellants -- handheld devices that aim to ward off the insects by emitting a high-frequency buzz -- do not prevent mosquitoes from spreading malaria, according to a review of studies published in the latest issue of The Cochrane Library journal, HealthDay News/Forbes reports. A. Ali Enayati, a lecturer of medical entomology at the Mazandaran University School of Medical Sciences in Iran, and colleagues analyzed 10 field-based studies conducted in North America, Russia and Africa to determine the effect of EMR devices on malaria control (HealthDay News/Forbes, 4/20). The researchers counted the number of times mosquitoes landed on exposed body parts -- such as arms, legs and feet -- during specific time periods when an EMR device was switched on or off. They found no significant differences in the landing rates with or without the EMR device. Some EMR device manufacturers say that the buzz mimics the flap of male mosquito wings, by which female mosquitoes reportedly are repelled. The devices are used indoors and outdoors, and some manufacturers say they repel mosquitoes within a range of 2.5 meters, or eight feet. However, some research suggests that female mosquitoes are not particularly sensitive to any sound. According to the researchers, it is a "concern" that worldwide sales of EMR devices have not slowed "because it is likely to lead to consumers not using other protective methods that are proven to work" (Sylvester, Health Behavior News Service, 4/17). EMR devices should not be "manufactured, advertised or used for mosquito bite and malaria prevention, as they do not do so," Enayati in a statement said. Joel Breman, senior scientific adviser at NIH's Fogerty International Center, in a statement said he agreed with the study, adding that "there is no evidence that electronic devices prevent malaria, and many other available options should be used" (HealthDay News/Forbes, 4/20). According to Nirbhay Kumar of Johns Hopkins Bloomberg School of Public Health, three of the 10 reviewed studies included the type of mosquito that transmits malaria. He added, "Perhaps a few confirmatory studies focusing in only malaria-endemic areas may either completely support their analysis or provide some hope for malaria control by this method, if at all applicable" (Health Behavior News Service, 4/17).

The study is available online.