[Development of chemoresistance of Plasmodium falciparum to chloroquine and mefloquine in Benin between 1980 and 1989].

Resistance of P. falciparum to chloroquine has been notified in 1986 in non-immune visitors. Authors organized surveys of in vivo and in vitro tests to follow evolution of the phenomena. The increase in number of P. falciparum strains resistant to chloroquine was sudden in 1986 but stopped to rise from this date, and even seemed to decrease gently. The geographical distribution of the resistance, restricted to the region of Cotonou, could be explained by illegitimate chloroquine distribution. But authors propose further investigations on relations between chloroquine resistant strains and the 3 anopheles species involved in malaria transmission in Benin. Resistance to mefloquine is rare in Cotonou region, but higher in rural zone.