Salissou Adamou, Zamanka Halima, Biyghe Binze Brigitte, Rivière Taiana, Tichit Magalie, Ibrahim Maman Laminou, Fandeur Thierry
Université de Ouagadougou, BP 364, Ouagadougou, Burkina Faso.
Unité de Parasitologie, Centre de Recherche Médicale et Sanitaire, 634 Bd de la Nation, BP 10887, YN034, Niamey, Niger.
Malar Res Treat. 2014;2014:614190. doi: 10.1155/2014/614190. Epub 2014 Nov 23.
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.
氯喹（CQ）耐药性在非洲广泛存在，但关于尼日尔的相关数据却很少。在引入以青蒿素为基础的联合用药并停用氯喹六年后，对从尼日尔南部15岁以下患单纯性恶性疟原虫疟疾的儿童中收集的26株疟原虫分离株，进行了Pfcrt单倍型（氨基酸56 - 118）以及氯喹和阿莫地喹体外反应的特征分析。在26株分离株中的22株发现了野生型Pfcrt单倍型CVMNK，仅在三个样本中观察到CVIET序列。我们还首次描述了一种新的CVINT单倍型。CVMNK的体外反应比CVIET疟原虫更好。将Pfcrt序列数据与从加蓬收集的另外26份受感染血样的数据进行了比较，加蓬的一个地区存在氯喹耐药性，用作对照。我们的研究结果表明，自上次获得尼日尔的估计数据以来，耐氯喹基因型已显著下降。在从加蓬类似条件下收集的样本子集中，未观察到对氯喹的分子耐药性有此类下降。这些结果对公共卫生具有重要意义，并支持了尼日尔自2005年以来实施的政策，该政策旨在提高抗疟药物的疗效和可及性，同时控制耐药性的传播。
