Malaria vector populations across ecological zones in Guinea Conakry and Mali, West Africa
Malaria vector populations across ecological zones in Guinea Conakry and Mali, West Africa
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DOI：
10.1186/s12936-016-1242-5
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发表时间：
2016-04-08
期刊：
影响因子：
3
通讯作者：
Riehle, Michelle M.
中科院分区：
文献类型：
--
作者：
Coulibaly, Boubacar;Kone, Raymond;Riehle, Michelle M.
背景：在撒哈拉以南西非，疟疾仍然是一个普遍存在的公共卫生问题。在这里，对马里和几内亚共和国(几内亚科纳克里)的四个地点的蚊媒种群进行了调查。本研究在相对较小的距离内对西非疟疾流行地区的主要生态区进行了抽样。方法：从幼虫池、成虫室内休息场所和室内外寻找成虫的人类宿主中采集蚊媒。蚊子是在横跨350公里的地点收集的，这些地点代表了干旱的大草原、潮湿的大草原、半森林和深森林生态区，这些地区以前对疟疾媒介种群知之甚少。对1425份蚊体标本进行分子分析，以确定蚊虫的种类、遗传属性、血源和疟原虫感染状况。结果：各生态区采集的按蚊以冈比亚按蚊和按蚊为主，干旱稀树草原和湿润地区均以大按蚊和冈比亚按蚊为主。通过在采样点使用多种收集方法，可以评估不同方法的潜在收集偏差。在所有研究地点都发现了L1014F kdr抗药性突变(kdr-w)。这种突变似乎已经从6年前的低频率几乎席卷到固定，尽管没有广泛使用杀虫剂来控制媒介。整个生态区的人类喂食率非常高，在干旱潮湿的大草原上只有一小部分动物血粉。约30%的新鲜血液喂养的蚊子恶性疟原虫阳性，而已确定感染的蚊子感染率低一个数量级。结论：这项研究代表了西非疟疾流行地区的详细媒介特征。深林研究地点包括2014年埃博拉病毒疫情的震中。由于几内亚计划采取新的疟疾控制措施，这些数据提供了一项基线衡量标准，并为评估未来干预措施的结果提供了机会。
Background: Malaria remains a pervasive public health problem in sub-Saharan West Africa. Here mosquito vector populations were explored across four sites in Mali and the Republic of Guinea (Guinea Conakry). The study samples the major ecological zones of malaria-endemic regions in West Africa within a relatively small distance.Methods: Mosquito vectors were sampled from larval pools, adult indoor resting sites, and indoor and outdoor human-host seeking adults. Mosquitoes were collected at sites spanning 350 km that represented arid savannah, humid savannah, semi-forest and deep forest ecological zones, in areas where little was previously known about malaria vector populations. 1425 mosquito samples were analysed by molecular assays to determine species, genetic attributes, blood meal sources and Plasmodium infection status.Results: Anopheles gambiae and Anopheles coluzzii were the major anophelines represented in all collections across the ecological zones, with A. coluzzii predominant in the arid savannah and A. gambiae in the more humid sites. The use of multiple collection methodologies across the sampling sites allows assessment of potential collection bias of the different methods. The L1014F kdr insecticide resistance mutation (kdr-w) is found at high frequency across all study sites. This mutation appears to have swept almost to fixation, from low frequencies 6 years earlier, despite the absence of widespread insecticide use for vector control. Rates of human feeding are very high across ecological zones, with only small fractions of animal derived blood meals in the arid and humid savannah. About 30 % of freshly blood-fed mosquitoes were positive for Plasmodium falciparum presence, while the rate of mosquitoes with established infections was an order of magnitude lower.Conclusions: The study represents detailed vector characterization from an understudied area in West Africa with endemic malaria transmission. The deep forest study site includes the epicenter of the 2014 Ebola virus epidemic. With new malaria control interventions planned in Guinea, these data provide a baseline measure and an opportunity to assess the outcome of future interventions.