Geographically extensive larval surveys reveal an unexpected scarcity of primary vector mosquitoes in a region of persistent malaria transmission in western Zambia.
Geographically extensive larval surveys reveal an unexpected scarcity of primary vector mosquitoes in a region of persistent malaria transmission in western Zambia.
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DOI：
10.1186/s13071-020-04540-1
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发表时间：
2021-02-01
影响因子：
3.2
通讯作者：
Shaw PW
中科院分区：
文献类型：
--
作者：
Cross DE;Thomas C;McKeown N;Siaziyu V;Healey A;Willis T;Singini D;Liywalii F;Silumesii A;Sakala J;Smith M;Macklin M;Hardy AJ;Shaw PW
赞比西河上游及其支流的巴罗茨洪泛区是一个高度动态的环境，季节性的洪水和迁徙使潜在的幼虫栖息地以及疟疾病媒蚊子的人类和牲畜血液食物不断变化。然而，已经开展了有限的昆虫学监测，以确定这些洪泛区及其周围的病媒群落特征。这些信息是必要的，因为尽管大量部署了驱虫蚊帐（ITNs）和室内滞留喷洒（IRS）来对付疟蚊媒介，但疟疾在赞比亚西部省巴洛特塞兰的传播仍然存在。在旱季和连续雨季高峰期之后，在两个卫生区沿着102公里的样带进行了地理上广泛的幼虫调查，以精确的空间分辨率进行。选取人类居住区典型按蚊飞行范围内的按蚊幼虫，通过细胞色素c氧化酶I和线粒体和核DNA内转录间隔区基因测序进行鉴定。这有助于在水文控制不同的生态区之间详细比较分类群特有的丰度模式。一个意想不到的初级载体的缺乏被揭示，与An。冈比亚和安哥拉。在已测序的995种按蚊中，富氏按蚊占不到2%。病媒生物群落以潜在次生病媒生物为主，以安蝇为主。库斯塔尼群种和安。squamosus。而An的分布。研究区冈比亚蝇高度聚集，次生媒介生物种类在干湿季节均普遍存在，且丰度与生态带之间存在一定的分类关系。候选病媒物种的多样性及其在不同水文生态系统中观察到的高相对丰度表明，这是一个高度适应性的传播系统，对环境变化具有弹性，并且可能仅针对部分病媒群落进行干预。幼虫调查结果表明，巴罗茨兰疟疾的残留传播主要是由次级媒介物种介导的，它们已知有黄昏和户外叮咬的倾向，因此对流行的媒介控制方法基本不敏感。
The Barotse floodplains of the upper Zambezi River and its tributaries are a highly dynamic environment, with seasonal flooding and transhumance presenting a shifting mosaic of potential larval habitat and human and livestock blood meals for malaria vector mosquitoes. However, limited entomological surveillance has been undertaken to characterize the vector community in these floodplains and their environs. Such information is necessary as, despite substantial deployment of insecticide-treated nets (ITNs) and indoor residual spraying (IRS) against Anopheles vectors, malaria transmission persists across Barotseland in Zambia’s Western Province. Geographically extensive larval surveys were undertaken in two health districts along 102 km of transects, at fine spatial resolution, during a dry season and following the peak of the successive wet season. Larvae were sampled within typical Anopheles flight range of human settlements and identified through genetic sequencing of cytochrome c oxidase I and internal transcribed spacer two regions of mitochondrial and nuclear DNA. This facilitated detailed comparison of taxon-specific abundance patterns between ecological zones differentiated by hydrological controls. An unexpected paucity of primary vectors was revealed, with An. gambiae s.l. and An. funestus representing < 2% of 995 sequenced anophelines. Potential secondary vectors predominated in the vector community, primarily An. coustani group species and An. squamosus. While the distribution of An. gambiae s.l. in the study area was highly clustered, secondary vector species were ubiquitous across the landscape in both dry and wet seasons, with some taxon-specific relationships between abundance and ecological zones by season. The diversity of candidate vector species and their high relative abundance observed across diverse hydro-ecosystems indicate a highly adaptable transmission system, resilient to environmental variation and, potentially, interventions that target only part of the vector community. Larval survey results imply that residual transmission of malaria in Barotseland is being mediated predominantly by secondary vector species, whose known tendencies for crepuscular and outdoor biting renders them largely insensitive to prevalent vector control methods.
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影响因子：
2.1
作者：
Fornadel, Christen M.;Norris, Laura C.;Norris, Douglas E.
通讯作者：
Norris, Douglas E.
DOI：
10.5772/65359
发表时间：
2016-01-01
期刊：
CURRENT TOPICS IN MALARIA
影响因子：
--
作者：
Afrane, Yaw Asare;Bonizzoni, Mariangela;Yan, Guiyun
通讯作者：
Yan, Guiyun
影响因子：
3.7
作者：
Cai, Xueliang;Haile, Alemseged Tamiru;Nhamo, Luxon
通讯作者：
Nhamo, Luxon
影响因子：
2.1
作者：
Ciubotariu, Ilinca I.;Jones, Christine M.;Norris, Douglas E.
通讯作者：
Norris, Douglas E.
影响因子：
3
作者：
Coetzee, Maureen
通讯作者：
Coetzee, Maureen