Mosquitoes can get a double dose of malaria

Carrying malaria makes mosquitoes more susceptible to infection with a second strain of the parasite that causes the disease, a new study demonstrates.

People can get infected with malaria parasites multiple times, but researchers knew little about how malaria affects the mosquitoes that are responsible for transmitting the disease.

In laboratory experiments, Laura Pollitt of the University of Edinburgh and colleagues fed female Anopheles stephensi mosquitoes mouse blood tainted with malaria parasites. Compared with uninfected mosquitoes, those that had picked up one strain of Plasmodium chabaudi malaria in their first blood meal were more likely to get infected with a second malaria strain later. Existing infections also increased the number of parasites of the second strain in the mosquitoes, Pollitt and colleagues report July 16 in PLOS Pathogens.

The team did not report whether mosquitoes carrying a double dose of malaria are more likely to pass the parasite to humans or other hosts.