Clinical malaria reduces human attractiveness to mosquitoes

Abstract

Evolutionary fitness concepts dictate that blood parasites should regulate their transmission success by enhancing the responsiveness of arthropod vectors to infectious hosts. We observed that the presence of trophozoite stages of Plasmodium falciparum in peripheral blood, combined with clinical malaria symptoms, actually reduced the attractiveness to Anopheles gambiae mosquitoes of one Kenyan male, relative to another. Their innate levels of attractiveness were restored within days, prior to the onset of gametocytaemia. These findings support the theory that a parasite-modulated change in host attractiveness occurs, but not at the stage when transmission from the human host to mosquito vector can be effected.