Most Mosquitoes Naturally Resistant to Malaria Parasite, Study Says

Most mosquitoes have developed resistance to the Plasmodium falciparum malaria parasite, a finding that could lead to new ways of eradicating mosquitoes that transmit the disease, according to a study published on Friday in the journal Science, the New York Times reports (McNeil, New York Times, 4/28). Kenneth Vernick, a microbiologist at the University of Minnesota, and colleagues collected female Anopheles gambiae mosquitoes in Mali and allowed them to produce a generation of offspring. The researchers then let the offspring feed on human blood infected with malaria (Xinhuanet, 4/28). After a week, the researchers dissected the mosquitoes and found that the parasite did not appear in 22% of the mosquitoes and appeared only in low numbers in many other mosquitoes. The researchers then compared mosquito genomes and found that when they disabled a particular gene, the parasites flourished. The study's findings could lead to new ways of eradicating malaria-carrying mosquitoes because it is more feasible to strengthen an existing gene than to insert an antimalarial gene, as scientists have long sought to do, according to the Times. In addition, the resistance is focused on one section of a chromosome and not in many sections, so it would be easier for scientists to manipulate it. Vernick said rather than releasing mosquitoes that have had their genes manipulated to resist the parasite, scientists might be able to use a soil fungus to kill the few mosquitoes that have not developed resistance to the parasite. However, according to Allan Schapira, a coordinator of the World Health Organization's malaria program, such a method would have to be tested for years for its safety and practicality (New York Times, 4/28).