A Microsporidian blocks Plasmodium falciparum transmission in Anopheles arabiensis mosquitoes

Malaria still imposes a huge disease burden on Africa and new control approaches are much needed. A new vertically transmitted species of Microsporidia was identified in the primary mosquito vector Anopheles arabiensis, at moderate prevalence in geographically dispersed populations in Kenya. Microsporidia MB infection is localized to the mosquito9s midgut and ovaries and does not appear to be pathogenic since it was not associated with significant reductions in adult host fecundity or survival. Field collected Microsporidia MB-infected An. arabiensis were never found to harbor P. falciparum gametocytes and on experimental infection with P. falciparum no sporozoites could be detected in Microsporidia MB-infected mosquitos. These data suggest that Microsporidia MB could be used for malaria transmission-blocking.