Efforts to block malaria transmission could be boosted by treating bed nets with antimalarial drugs in addition to insecticides. This strategy, proposed in a study published online this week in Nature, may aid efforts to control malaria in areas with insecticide-resistant mosquito populations.

One of the most effective methods to prevent malaria spread has been the use of bed nets sprayed with insecticide. However, Anopheles mosquitos are becoming resistant to insecticides and the risk of malaria spread is on the rise. New approaches to control this disease are urgently needed.

Flaminia Catteruccia and colleagues demonstrate that exposing female Anopheles gambiae mosquitos to parasite inhibitors, such as atovaquone (an antimalarial drug already used in humans), blocks the development and transmission of the malaria parasite Plasmodium falciparum. This effect is achieved with low doses of the drug and with exposure times as low as six minutes, similar to the amount of time mosquitos rest on bed nets while seeking a host. Atovaquone inhibits the normal functioning of the mitochondria in the cells of P. falciparum, killing the parasite and preventing transmission without affecting mosquito survival and reproduction. Similar effects are seen with other drugs that act on the same target as atovaquone, the authors report, which suggests that parasite mitochondrial function is a good target for arresting P. falciparum within mosquitoes.

The authors model how the observed effects would affect malaria transmission dynamics. They predict that the inclusion of P. falciparum inhibitors on mosquito nets could substantially mitigate the global health impact of insecticide resistance.