The Department of Biological Sciences, Purdue University, West Lafayette, IN.
The W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.
J Med Entomol. 2020 Nov 13;57(6):1782-1792. doi: 10.1093/jme/tjaa132.
Despite ongoing malaria control efforts implemented throughout sub-Saharan Africa, malaria remains an enormous public health concern. Current interventions such as indoor residual spraying with insecticides and use of insecticide-treated bed nets are aimed at targeting the key malaria vectors that are primarily endophagic and endophilic. Anopheles coustani s.l., an understudied vector of malaria, is a species previously thought to exhibit mostly zoophilic behavior. Like many of these understudied species, An. coustani has greater anthropophilic tendencies than previously appreciated, is often both endophagic and exophagic, and carries Plasmodium falciparum sporozoites. The aim of this study was to explore genetic variation of An. coustani mosquitoes and the potential of this species to contribute to malaria parasite transmission in high transmission settings in Zambia and the Democratic Republic of the Congo (DRC). Morphologically identified An. coustani specimens that were trapped outdoors in these study sites were analyzed by PCR and sequencing for species identification and bloodmeal sources, and malaria parasite infection was determined by ELISA and qPCR. Fifty An. coustani s.s. specimens were confirmed by analysis of mitochondrial DNA cytochrome c oxidase subunit I (COI) and ribosomal internal transcribed spacer region 2 (ITS2). Maximum likelihood phylogenetic analysis of COI and ITS2 sequences revealed two distinct phylogenetic groups within this relatively small regional collection. Our findings indicate that both An. coustani groups have anthropophilic and exophagic habits and come into frequent contact with P. falciparum, suggesting that this potential alternative malaria vector might elude current vector control measures in northern Zambia and southern DRC.
尽管在撒哈拉以南非洲各地持续实施疟疾控制工作，但疟疾仍然是一个巨大的公共卫生关注问题。目前的干预措施，如室内滞留喷洒杀虫剂和使用经杀虫剂处理的蚊帐，旨在针对主要是内吸性和内生性的疟疾传播媒介。作为疟疾研究较少的媒介之一，库氏按蚊是一种以前被认为主要表现为嗜动物性行为的物种。像许多研究较少的物种一样，库蚊具有比以前认识到的更大的嗜人倾向，通常既是内吸性的又是外吸性的，并携带恶性疟原虫孢子。本研究旨在探讨库蚊的遗传变异以及该物种在赞比亚和刚果民主共和国（DRC）高传播地区对疟原虫传播的潜在贡献。在这些研究地点户外诱捕的形态学鉴定的库蚊标本通过 PCR 和测序进行物种鉴定和血液来源分析，并通过 ELISA 和 qPCR 确定疟原虫感染情况。通过对线粒体 DNA 细胞色素 c 氧化酶亚基 I (COI) 和核糖体内部转录间隔区 2 (ITS2) 的分析，确认了 50 只库蚊 s.s. 标本。COI 和 ITS2 序列的最大似然系统发育分析显示，在这个相对较小的区域采集中存在两个不同的系统发育群。我们的研究结果表明，这两个库蚊群都具有嗜人和外吸性的习惯，并经常接触恶性疟原虫，这表明这种潜在的替代疟疾传播媒介可能逃避赞比亚北部和刚果民主共和国南部目前的病媒控制措施。
