Background The scale up of indoor residual spraying and long-lasting insecticidal nets, together with other interventions have considerably reduced the malaria burden in The Gambia. This study examined the biting and resting preferences of the local insecticide-resistant vector populations. Method Indoor and outdoor-resting Anopheles gambiae mosquitoes were collected between July and October 2019 from ten villages in five regions in The Gambia using pyrethrum spray collection (indoor) and prokopack aspirator from pit traps (outdoor). Polymerase chain reaction assays were performed to identify molecular species, insecticide resistance mutations, Plasmodium infection rate and host blood meal. Results A total of 844 mosquitoes were collected both indoors (421, 49.9%) and outdoors (423, 50.1%). Four main vector species were identified, including An. arabiensis (indoor: 15%, outdoor: 26%); An. coluzzii (indoor: 19%, outdoor: 6%), An. gambiae s.s. (indoor: 11%, outdoor: 16%), An. melas (indoor: 2%, outdoor: 0.1%) and hybrids of An. coluzzii-An. gambiae (indoors: 3%, outdoors: 2%). A significant preference for outdoor resting was observed in An. arabiensis (Pearson X 2 =22.7, df=4, P<0.001) and for indoor resting in An. coluzzii (Pearson X 2 =55.0, df=4, P<0.001). Prevalence of the voltage-gated sodium channel ( Vgsc ) -1014S was higher in the indoor-resting (allele freq. = 0.96, 95%CI: 0.78–1) than outdoor-resting (allele freq. = 0.82, 95%CI: 0.76–0.87) An. arabiensis population. For An. coluzzii, the prevalence of most mutation markers were higher in the outdoor (allele freq. = 0.92, 95%CI: 0.81–0.98) than indoor-resting (allele freq. = 0.78, 95%CI: 0.56–0.86) mosquitoes. Sporozoite positivity rate was 1.3% (95% CI: 0.5–2%). Indoor-resting An. coluzzii had mainly fed on human blood while indoor-resting An. arabiensis, animal blood. Conclusion The indoor-resting behavior of An. arabiensis that preferred animal blood and had low sporozoite rates, may be determined by the Vgsc-1014S mutation. Control interventions may include complementary vector control approaches such as zooprophylaxis.

中文翻译：

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冈比亚疟疾媒介的叮咬和休息偏好

背景扩大室内残留喷雾剂和长效杀虫网的规模，以及其他干预措施，已大大减轻了冈比亚的疟疾负担。这项研究检查了本地抗药性媒介种群的咬和休息偏好。方法在2019年7月至10月之间，使用除虫菊喷雾收集器（室内）和坑坑诱捕器（室外）的prokopack吸气器从冈比亚五个地区的10个村庄收集了室内和室外休息的冈比亚按蚊。进行聚合酶链反应测定以鉴定分子种类，杀虫剂抗性突变，疟原虫感染率和宿主血粉。结果在室内（421个，占49.9％）和室外（423个，占50.1％）共收集到844种蚊子。确定了四个主要的载体种类，包括An。阿拉伯（室内：15％，室外：26％）; 一个。coluzzii（室内：19％，室外：6％），冈比亚SS（室内：11％，室外：16％），An。梅拉斯（室内：2％，室外：0.1％）和An。的杂种。coluzzii-An。冈比亚（室内：3％，户外：2％）。在An中观察到户外休息的偏好。阿拉伯（Pearson X 2 = 22.7，df = 4，P <0.001）并用于An。结肠炎（Pearson X 2 = 55.0，df = 4，P <0.001）。在室内休息时（等位基因频率= 0.96，95％CI：0.78-1），电压门控钠通道（Vgsc）-1014S的发生率要比室外休息时（等位基因频率= 0.82，95％CI）高。 0.76-0.87）An。阿拉伯种群。为。结肠炎，大多数突变标记的患病率在室外（等位基因频率= 0.92，95％CI：0.81-0.98）比在室内休息（等位基因频率= 0.78，95％CI：0.56-0.86）高。子孢子阳性率为1.3％（95％CI：0.5-2％）。室内休息 在室内休息时，coluzzii主要以人体血液为食。阿拉伯动物血。结论An的室内休息行为。可以通过Vgsc-1014S突变来确定更喜欢动物血液且子孢子发生率较低的阿拉伯半岛。控制干预措施可以包括互补的载体控制方法，例如动物预防。