INFECTIVITY OF MALARIAL PARASITES TO MOSQUITOS - THE INTERDEPENDENT ROLES OF PARASITE, VECTOR AND HOST

It has been possible to infect mosquitoes routinely with cultured game tocytes of Plasmodium falciparum Since 1980. This has enabled the deve lopment of a reliable bio-assay for potential transmission-blocking va ccines and research on the role of specific antibodies from the host o n the parasitic stages in the mosquito midgut. After some development and fine-tuning of the assay, it became apparent that the immune respo nses of the human host, as well as factors from the parasite and the m osquito, determined the final outcome of the mosquito infection. The a ge of the mosquito, crowding of parasites inside the peritrophic membr ane and the quantity and particularly the quality of the gametocytes i ngested all influence the chance of successful transmission. Cytokines and/or other mediators of inflammation from the human host can also r educe transmission, probably by promoting phagocytosis of the freshly emerged gametes by leucocytes in the bloodmeal.