Studies on chloroquine-resistance of Plasmodium falciparum in Upper Volta and Liberia, West Africa.

The emergence of strains of Plasmodium falciparum resistant to normal dosages of chloroquine or other 4-aminoquinolines has caused concern in a number of malarious areas. Well-documented reports have confirmed this resistance in wide areas of South-East Asia and in some areas of South America. Occasional reports have been received from parts of West Africa, and the present investigation sought to clarify the situation in two areas, Ouagadougou, Upper Volta, and Kpain, Liberia, from which such reports had emanated. Studies were carried out to determine the sensitivity of local strains of P. falciparum to chloroquine. The results, based on the rapidity of parasite clearance, indicated a normal sensitivity in the cases treated. Although it is concluded that strains of P. falciparum with significant resistance to chloroquine are not at present a problem in the areas concerned, a watch should be kept for the possible future emergence of this problem.