IN-VITRO SENSITIVITY OF PLASMODIUM-FALCIPARUM TO HALOFANTRINE COMPARED WITH CHLOROQUINE, QUININE AND MEFLOQUINE IN THE REGION OF BOBO-DIOULASSO, BURKINA-FASO (WEST-AFRICA)

The in vitro sensitivity of P. falciparum drug-resistant isolates was evaluated in the region of Bobo-Dioulasso during the 1995 and 1996 rai ny seasons. Two routinely used antimalarials (chloroquine and quinine) and two new antimalarials (mefloquine and halofantrine) were assessed using 24-hour in vitro cultures with tritiated hypoxanthine and a par asite density greater than or equal to 4,000/mu l of blood. The propor tion of chloroquine-resistant isolates was 20% in 1995 and 19% in 1996 , whilst in 1996, the proportion of isolates resistant to halofantrine was greater than in 1995 (9.6% versus l%). No significant differences were seen in the mean IC50 values in relation to the susceptibility o f chloroquine-resistant or chloroquine-sensitive isolates to mefloquin e and halofantrine. In the case of quinine, the mean IC(50 )values wer e significantly higher in chloroquine-resistant isolates than in chlor oquine-sensitive ones. A significant positive correlation was found be tween the following IC50 values: chloroquine versus quinine, quinine v ersus mefloquine and mefloquine versus halofantrine.