Chloroquine-resistant falciparum malaria in Madagascar and Kenya

Three cases of infection with chloroquine-resistant, Plasmodium falciparum malaria are described. In two cases the infection was acquired in Madagascar; the third infection was acquired in Kenya, all in spite of regular prophylaxis.The WHO extended field tests for the sensitivity of falciparum malaria to chloroquine (1973) were followed by recrudescences of the RI pattern in all three cases. The chloroquine concentrations in serum were measured, both during treatment and at the time of re-appearance of parasites, and were found to be adequate for sensitive strains. In vitro tests were performed and showed resistance in one of the cases from Madagascar and probable resistance in the other, but failed in the case from Kenya.It is concluded that Madagascar is yet another area of Africa where strains of P. falciparum with RI resistance have appeared.