During the past 5 years chloroquine-resistant Plasmodium falciparum infections have been noted with increasing frequency in Zaire. The first cases were demonstrated in vivo in the eastem part of the country, in 1982.1 In 1983, combined in vivo and in vitro studies conducted in Kinshasa (western Zaire) and in Mbuji-Mayi (central Zaire) failed to detect resistance. 2 Since 1984 the occurrence of chloroquine resistance in Kinshasa has been demonstrated both in vivo (J. G. Breman, CDC, personal communication) and in vitro.3 To determine the extent of in vitro choroquine resistance in relation to in vitro response to other antimalarial drugs, we conducted drug resistance tests in Kinshasa in which we evaluated the response of P. falciparum to chloroquine, quinine, and pyrimethamine.
We thank Jonathan M. Mann, Bongo Lyamba, and Jean-Jacques Salaun for their support and advice, the laboratory staff of the Projet SIDA (Ministry of Health and Social Affairs, Kinshasa), and the nursing staff of the Mama Yemo Hospital for technical assistance.
Delacollette C., Embonga B., Malengreau M. , 1983. Response to chloroquine of infections with Plasmodium falciparum in the Kivu region of Zaire. Preliminary observations. Ann. Soc. Belge Med. Trop., 63: 171–173.
Nguyen-Dinh P., Schwartz I. K., Sexton J. D., Bomboto E., Botomwito B., Kalisa R., Ngimbi N. P., Wery M. , 1985. In vivo and in vitro susceptibility to chloroquine of Plasmodium falciparum in Kinshasa and Mbuji-Mayi, Zaire. Bull. W.H.O., 63: 325–330.
Ngimbi N. P., Wery M., Henry M. C., Mulumba M. P. , 1985. Response in vivo à la chloroquine au cours du traitement du paludisme a Plasmodium falciparum en region suburbaine de Kinshasa, Zaire. Ann. Soc. Belge Med. Trop., 65 (Suppl. 2): 123–135.
Nguyen-Dinh P., Spencer H. C., Chemangey-Masaba S., Churchill F. C. , 1982. Susceptibility of Plasmodium falciparum to pyrimethamine and sulfadoxine-pyrimethamine in Kisumu, Kenya. Lancet, 1: 823–825.