Low Prevalence ofPfcrtResistance Alleles among Patients with Uncomplicated Falciparum Malaria in Niger Six Years after Chloroquine Withdrawal

[摘要] Chloroquine (CQ) resistance is widespread in Africa, but few data are available for Niger.Pfcrthaplotypes (aa 56–118) andex vivoresponses to CQ and amodiaquine were characterized for 26 isolates collected in South Niger from children under 15 years of age suffering from uncomplicatedfalciparummalaria, six years after the introduction of artemisinin-based combinations and the withdrawal of CQ. The wild-typePfcrthaplotype CVMNK was found in 22 of the 26 isolates, with CVIET sequences observed in only three of the samples. We also describe for the first time a new CVINT haplotype. Theex vivoresponses were better for CVMNK than for CVIET parasites.Pfcrtsequence data were compared with those obtained for 26 additional parasitized blood samples collected in Gabon, from an area of CQ resistance used as a control. Our findings suggest that there has been a significant decline in CQ-resistant genotypes since the previous estimates for Niger were obtained. No such decline in molecular resistance to CQ was observed in the subset of samples collected in similar conditions from Gabon. These results have important implications for public health and support the policy implemented in Niger since 2005, which aims to increase the efficacy and availability of antimalarial drugs whilst controlling the spread of resistance.

[学科分类] 传染病学