Malaria kills over 1,000,000 people worldwide each year with the heaviest toll among pregnant women and children under five. Despite more effective drugs and better mosquito nets, the problem is not getting any better due to bureaucratic delays and health system breakdowns in Africa. Mosquitoes also develop resistance to every insecticide including DDT.
An unlikely hero in this deadly drama is a pair of fungi that have already been licensed to control aphids, termites, and other insect pests. Two studies in the journal Science report a "deliverable product" could be ready in 3 to 5 years with proper funding for research and development. Independent scientists too are encouraged by the research.
The fungi, known as Beaueria bassiana fungus and Metarhizium anisopliae fungus, are harmless to humans, even if ingested, due to the elevated body temperature. The same is not true when many species of insects are exposed to the fungi, however. The fungi will infect the insects rather quickly and kill them in a matter of days.
In the case of mosquitoes, both studies found the fungi to be effective in killing a large percentage of insects in a matter of 4 to 14 days depending on which fungus was used. Surviving mosquitoes were seen to fly poorly and bite less and have slower developing parasites. Since malaria requires parasites to develop in the mosquitoes (moving from their abdomen to their saliva) over the course of about 14 days, a shorter lifespan in the mosquito (or longer development time for the parasites) will result in far fewer bites with active parasites.
The fungi were seen to reduce potential malaria transmission by 75%. The lethality of the spores decreased in time, so spraying would have to be repeated monthly. This presents a problem in rural and remote areas.