Plasmodium falciparum chloroquine resistance in 1998 in Niamey, republique of Niger

In vivo tests for Plasmodium falciparum were carried out in 1998 during the rainy season among children in Niamey, in the Republic of Niger. Chloroquine was prescribed at 25 mg/kg for 3 days in febrile patients with uncomplicated P. falciparum malaria. Forty-five 1-5 year-olds and thirty-three 6-15 year-olds were included in the study. A group of 53 adult patients was also surveyed to evaluate the efficacy of chloroquine in semi-immune persons. Body temperature and blood smears including parasitemia were recorded on days 0, 3, 7 and 14. Less than 10% of the patients were delinquent. Around 75% of the patients were successfully treated in the 1-5 year-olds and 6-15 year old age groups. Relapses were observed in 20% of the 1-5 year-olds (early relapses 8.9%, late relapses 11.1%) and in 16.7% in the 1-15 year-olds (early relapses 6.4%, late relapses 10.3%). Among adults, successful treatment was obtained in 86.8% of the cases and early and late relapses were respectively observed in 3.8% and 1.9% of the cases. All the patients with malaria relapses were cured with second-line treatments (pyrimethamine-sulfadoxine or quinine). According to these results, chloroquine resistance appears to be moderate in Niamey. Therefore chloroquine should remain the first line treatment of uncomplicated P. falciparum malaria in this population.