[Malaria vectors and their role in transmission, in Manarintsoa in the Highland Plateaux of Madagascar from 1988 to 1990].

To evaluate the factors determining malaria transmission level, entomological and parasitological surveys were conducted from October 1988 to February 1990 in MANARINTSOA, in the central highland plateaux of MADAGASCAR. Mosquitoes were collected during 928 man-nights of captures, in pit shelters and in indoors resting sites. The malaria vectors were An. arabiensis and An. funestus, with no evidence of the presence of An. gambiae s.s. The vectors were mainly exophilic and zoophilic. The index of stability was below 1.5. The sporozoite rate was 0.11 for An. gambiae s.l. and 0.47 for An. funestus. The transmission level was low: the inoculation rate was 0.91 infected bite per man and per year and the infection risk 0.62. Transmission occurs 7 months per year, from November to May. In the human population parasite rates fluctuated from 29% in October to 53% in May.