Genetically manipulated virus could prevent mosquitoes from transmitting malaria, study says

A genetically manipulated version of densovirus could prevent Anopheles gambiae mosquitoes from transmitting malaria, according to a study published last week in PLoS Pathogens, the New York Times reports.

Jason Rasgon, an entomology professor at Johns Hopkins Malaria Research Institute, and colleagues discovered the densovirus "in a complete accident" while conducting separate research that involved infecting mosquitoes with bacteria (McNeil, New York Times, 8/25). The researchers found that the virus repeatedly appeared in a gel used to detect the bacteria. Although it is not "uncommon" to find viruses during experiments, the researchers decided to "investigate" the densovirus because it continued to appear, Rasgon said.

The researchers found that although the virus does not seem to harm the mosquitoes, it can infect mosquito larvae (PTI/Times of India, 8/26). To determine whether the virus could be manipulated, the researchers produced a harmless green fluorescent protein in adult mosquitoes, which could be spotted easily under microscopes (Malaria Research Institute release, 8/22).

According to Rasgon, scientists could manipulate the virus to produce a "lethal toxin" in infected mosquitoes to cause them to die after 10 days, which is long enough to prevent resistance to the virus from developing but too short for the mosquitoes to transmit malaria to humans (PTI/Times of India, 8/26). However, the research likely will take between five and 15 years because of regulatory and ethical issues associated with releasing the virus into wild mosquitoes, Rasgon said.

Densoviruses have been found in other insects but do not infect humans or other mammals, the Times reports (New York Times, 8/25).

The study is available online.