National Institute of Public Hygiene, Abidjan, Côte d'Ivoire.
Department of Disease Control, London School of Hygiene and Tropical Medicine, LondonUK.
J Med Entomol. 2021 Jul 16;58(4):1808-1816. doi: 10.1093/jme/tjab045.
From 2008 to 2017, the city of Abidjan, Côte d'Ivoire experienced several Aedes-borne disease epidemics which required control of the vector mosquito population based on the reduction of larval habitats and insecticidal sprays for adult mosquitoes. This study was undertaken to assess the insecticide susceptibility status of Aedes aegypti (Linnaeus) in the city of Abidjan. Immature Ae. aegypti were sampled from several larval habitats within seven communes of Abidjan and reared to adults. Three to five days old F1 emerged adults were tested for susceptibility using insecticide-impregnated papers and the synergist piperonyl butoxide (PBO) following WHO bioassay guidelines. The results showed that Ae. aegypti populations from Abidjan were resistant to 0.1% propoxur, and 1% fenitrothion, with mortality rates ranging from 0% to 54.2%. Reduced susceptibility (93.4-97.5% mortality) was observed to 0.05% deltamethrin, 0.75% permethrin, 0.05% lambda-cyhalothrin, 5% malathion, and 0.8% chlorpyrifos-methyl. This reduced susceptibility varied depending on the insecticide and the collection site. The restoration of mortality when the mosquitoes were pre-exposed to the synergist PBO suggests that increased activity of oxidases could be contributing to resistance. Three kdr mutations (V410L, V1016I, and F1534C) were present in populations tested, with low frequencies for the Leu410 (0.28) and Ile1016 (0.32) alleles and high frequencies for the Cys1534 allele (0.96). These findings will be used to inform future arbovirus vector control activities in Abidjan.
从 2008 年到 2017 年，科特迪瓦阿比让市经历了几次埃及伊蚊传播疾病的疫情，这些疫情需要通过减少幼虫栖息地和对成蚊进行杀虫喷雾来控制蚊虫种群。本研究旨在评估阿比让市埃及伊蚊（Linnaeus）的杀虫剂敏感性状况。从阿比让七个区的几个幼虫栖息地中采集了埃及伊蚊幼虫，并将其饲养为成虫。用浸渍杀虫剂的纸张和增效剂胡椒基丁醚（PBO）按照世界卫生组织生物测定指南测试了 3 到 5 天大的 F1 期成虫的敏感性。结果表明，阿比让的埃及伊蚊种群对 0.1%丙硫磷和 1%fenitrothion 具有抗药性，死亡率范围为 0%至 54.2%。对 0.05%溴氰菊酯、0.75%氯菊酯、0.05%高效氯氟氰菊酯、5%马拉硫磷和 0.8%毒死蜱表现出降低的敏感性（死亡率 93.4-97.5%）。这种降低的敏感性取决于杀虫剂和采集地点。当蚊子预先暴露于增效剂 PBO 时，死亡率恢复表明氧化酶的活性增加可能导致了抗药性。在所测试的种群中存在三种 kdr 突变（V410L、V1016I 和 F1534C），亮氨酸 410（0.28）和异亮氨酸 1016（0.32）等位基因的频率较低，半胱氨酸 1534 等位基因的频率较高（0.96）。这些发现将用于指导未来在阿比让开展的虫媒病毒病媒介控制活动。
