[Ecological factors in the renewed outbreak of malaria in Madagascar]

The new epidemic of malaria which spread on the Madagascar high plateau in 1986-1987 is due to the combination of several factors (some of which are analysed by the authors, especially those related to anopheles, parasite and man). The authors compare the situations on the high Plateau and on St Mary Island, on the East Madagascar Coast, where the malaria is stable. Concerning the vector, the most interesting fact is the come-back of Anopheles funestus on the high Plateau from which it had disappeared at the beginning of the fifties. In this area, An.arabiensis seems to be the only representative of the gambiae complex whereas it is An. gambiae s.s. in St Mary Island. The parasite is getting more and more resistant to chloroquine. Nevertheless, man seems to develop protection, but it is difficult to analyse the markers which would prove the protection. However, that protection was assessed, on the humoral and cellular level, against the peptides of the RESA (Ring Infected Erythrocytes Surface Antigen), the circumsporozoite protein and the antigen E.