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Malaria Research and Treatment
Volume 2014 (2014), Article ID 614190, 7 pages
http://dx.doi.org/10.1155/2014/614190
Research Article

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

1Université de Ouagadougou, BP 364, Ouagadougou, Burkina Faso
2Unité de Parasitologie, Centre de Recherche Médicale et Sanitaire, 634 Bd de la Nation, BP 10887, YN034, Niamey, Niger
3Unité de Parasitologie Médicale, Centre International de Recherches Médicales de Franceville, BP 769, Franceville, Gabon
4Genopôle de l’Ile de France, Plate-Forme Génomique, Institut Pasteur, 28 Rue du Dr ROUX, 75015 Paris, France
5Division Internationale, Institut Pasteur, 28 Rue du Dr ROUX, 75015 Paris, France

Received 16 September 2014; Accepted 4 November 2014; Published 23 November 2014

Academic Editor: Ananias Escalante

Copyright © 2014 Adamou Salissou et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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.