The malaria parasite produces a molecule that affects red blood cells, luring mosquitoes to bite infected people, and may enhance the parasite's spread.

Ingrid Faye at Stockholm University and her colleagues found that the parasite Plasmodium falciparum produces a metabolite called HMBPP. This stimulates red blood cells to release carbon dioxide and other gases that together attract the Anopheles gambiae mosquito, a major malaria vector. The mosquitoes preferred human blood containing HMBPP, ingesting larger amounts of this than HMBPP-free blood. Mosquitoes consuming malaria-infected blood laced with extra HMBPP also had more parasites in their salivary glands than did those ingesting just infected blood, suggesting that the molecule boosts the insects' susceptibility to infection.

HMBPP altered the expression of certain neural and immune genes in mosquitoes, supporting the idea that the molecule changes mosquito feeding behaviour and immune function to support malaria transmission.

Science http://doi.org/bzkw (2017)