[Drug resistance of Plasmodium falciparum in the Congo. 2. Comparative study in vivo of chloroquine and amodiaquine in Brazzaville schoolchildren (November 1986)].

This study was conducted in Brazzaville, the capital of Congo, for the purpose of assessing the resistance to chloroquine and amodiaquine of Plasmodium falciparum. 64 in vivo tests using the WHO protocol--trial period 7 days after administration over 3 days of a dose of 25 mg/kg (N = 31 for chloroquine, 33 for amodiaquine)--were performed in schoolchildren aged 6 to 7 years, with parasite counts of at least 1,000 trophozoites/mm3. The respective percent resistance was found to be 38.7% (9.7% at the RII level, 29% at the RI level) for chloroquine and 21.2% (3% at the RII levels, 18.2% at the RI level) for amodiaquine. Based on these percentages and levels of resistance, and on changes in parasite counts, amodiaquine does not appear to be more efficacious. The emergence and rapid simultaneous spreading of resistance to these two drugs are discussed.