title: Low Prevalence of Pfcrt Resistance Alleles among Patients with Uncomplicated Falciparum Malaria in Niger Six Years after Chloroquine Withdrawal.
abstract: Chloroquine (CQ) resistance is widespread in Africa, but few data are available for Niger. Pfcrt haplotypes (aa 56-118) and ex vivo responses to CQ and amodiaquine were characterized for 26 isolates collected in South Niger from children under 15 years of age suffering from uncomplicated falciparum malaria, six years after the introduction of artemisinin-based combinations and the withdrawal of CQ. The wild-type Pfcrt haplotype 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. The ex vivo responses were better for CVMNK than for CVIET parasites. Pfcrt sequence 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.
authors.affiliation: Université de Ouagadougou, BP 364, Ouagadougou, Burkina Faso.
authors.forename: Adamou
authors.initials: A
authors.lastname: Salissou
authors.affiliation: Unité de Parasitologie, Centre de Recherche Médicale et Sanitaire, 634 Bd de la Nation, BP 10887, YN034, Niamey, Niger.
authors.forename: Halima
authors.initials: H
authors.lastname: Zamanka
authors.affiliation: Unité de Parasitologie Médicale, Centre International de Recherches Médicales de Franceville, BP 769, Franceville, Gabon.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Biyghe Binze
authors.affiliation: Unité de Parasitologie, Centre de Recherche Médicale et Sanitaire, 634 Bd de la Nation, BP 10887, YN034, Niamey, Niger.
authors.forename: Taiana
authors.initials: T
authors.lastname: Rivière
authors.affiliation: Genopôle de l'Ile de France, Plate-Forme Génomique, Institut Pasteur, 28 Rue du Dr ROUX, 75015 Paris, France.
authors.forename: Magalie
authors.initials: M
authors.lastname: Tichit
authors.affiliation: Unité de Parasitologie, Centre de Recherche Médicale et Sanitaire, 634 Bd de la Nation, BP 10887, YN034, Niamey, Niger.
authors.forename: Maman Laminou
authors.initials: ML
authors.lastname: Ibrahim
authors.affiliation: Unité de Parasitologie, Centre de Recherche Médicale et Sanitaire, 634 Bd de la Nation, BP 10887, YN034, Niamey, Niger ; Unité de Parasitologie Médicale, Centre International de Recherches Médicales de Franceville, BP 769, Franceville, Gabon ; Division Internationale, Institut Pasteur, 28 Rue du Dr ROUX, 75015 Paris, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Fandeur