Both infected and uninfected mosquitoes are attracted toward malaria infected birds

BACKGROUND: The biting behaviour of mosquitoes is crucial for the transmission of malaria parasites. This study focuses on the feeding behaviour of Culex pipiens mosquitoes with regard to the infection status by the avian malaria parasite Plasmodium relictum (lineage SGS1). METHODS: Uninfected and sporozoite-infected mosquitoes were provided with a choice between an uninfected bird and a bird undergoing a chronic P. relictum infection. Mosquito choice is assessed by microsatellite typing of the ingested blood. RESULTS: Chronically infected birds are more attractive to mosquitoes. This choice is not altered by the infection status of the mosquitoes: both infected and uninfected mosquitoes have similar host choice behaviours and are more attracted towards infected birds. CONCLUSIONS: These results support some, but not all predictions derived from the hypothesis that malaria parasites can manipulate the behaviour of their mosquito vectors to enhance their transmission. The possible mechanisms driving this manipulation, the evolutionary dynamics leading to the modification of the biting behaviour of mosquitoes by Plasmodium sp. as well as the implications for malaria epidemiology are discussed.