PDF(Pubmed)
Abstract：
BACKGROUND: Anopheles coluzzii is a primary vector of malaria found in West and Central Africa, but its presence has hitherto never been documented in Kenya. A thorough understanding of vector bionomics is important as it enables the implementation of targeted and effective vector control interventions. Malaria vector surveillance efforts in the country have tended to focus on historically known primary vectors. The current study sought to determine the taxonomic status of samples collected from five different malaria epidemiological zones in Kenya as well as describe the population genetic structure and insecticide resistance profiles in relation to other An. coluzzii populations.
METHODS: Mosquitoes were sampled as larvae from Busia, Kwale, Turkana, Kirinyaga and Kiambu counties, representing the range of malaria endemicities in Kenya, in 2019 and 2021 and emergent adults analysed using Whole Genome Sequencing (WGS) data processed in accordance with the Anopheles gambiae 1000 Genomes Project phase 3. Where available, historical samples from the same sites were included for WGS. Comparisons were made with An. coluzzii cohorts from West and Central Africa.
RESULTS: This study reports the detection of An. coluzzii for the first time in Kenya. The species was detected in Turkana County across all three time points from which samples were analyzed and its presence confirmed through taxonomic analysis. Additionally, there was a lack of strong population genetic differentiation between An. coluzzii from Kenya and those from the more northerly regions of West and Central Africa, suggesting they represent a connected extension to the known species range. Mutations associated with target-site resistance to DDT and pyrethroids and metabolic resistance to DDT were found at high frequencies up to 64%. The profile and frequencies of the variants observed were similar to An. coluzzii from West and Central Africa but the ace-1 mutation linked to organophosphate and carbamate resistance present in An. coluzzii from coastal West Africa was absent in Kenya.
CONCLUSIONS: These findings emphasize the need for the incorporation of genomics in comprehensive and routine vector surveillance to inform on the range of malaria vector species, and their insecticide resistance status to inform the choice of effective vector control approaches.
METHODS: Mosquitoes were sampled as larvae from Busia, Kwale, Turkana, Kirinyaga and Kiambu counties, representing the range of malaria endemicities in Kenya, in 2019 and 2021 and emergent adults analysed using Whole Genome Sequencing (WGS) data processed in accordance with the Anopheles gambiae 1000 Genomes Project phase 3. Where available, historical samples from the same sites were included for WGS. Comparisons were made with An. coluzzii cohorts from West and Central Africa.
RESULTS: This study reports the detection of An. coluzzii for the first time in Kenya. The species was detected in Turkana County across all three time points from which samples were analyzed and its presence confirmed through taxonomic analysis. Additionally, there was a lack of strong population genetic differentiation between An. coluzzii from Kenya and those from the more northerly regions of West and Central Africa, suggesting they represent a connected extension to the known species range. Mutations associated with target-site resistance to DDT and pyrethroids and metabolic resistance to DDT were found at high frequencies up to 64%. The profile and frequencies of the variants observed were similar to An. coluzzii from West and Central Africa but the ace-1 mutation linked to organophosphate and carbamate resistance present in An. coluzzii from coastal West Africa was absent in Kenya.
CONCLUSIONS: These findings emphasize the need for the incorporation of genomics in comprehensive and routine vector surveillance to inform on the range of malaria vector species, and their insecticide resistance status to inform the choice of effective vector control approaches.
摘要：
背景：结肠按蚊是在西非和中非发现的疟疾的主要媒介，但它的存在迄今从未在肯尼亚被记录在案。对媒介生物学的透彻了解非常重要，因为它可以实施有针对性和有效的媒介控制干预措施。该国的疟疾病媒监测工作往往侧重于历史上已知的主要病媒。当前的研究旨在确定从肯尼亚五个不同疟疾流行病学区收集的样品的分类状况，并描述与其他A相关的种群遗传结构和杀虫剂抗性概况。Coluzzii种群。
方法：以来自Busia的幼虫为样本的蚊子，Kwale,图尔卡纳,Kirinyaga和Kiambu县，代表肯尼亚疟疾流行的范围，在2019年和2021年，使用根据冈比亚按蚊1000基因组项目第3阶段处理的全基因组测序（WGS）数据进行了分析。如有,WGS包括来自相同地点的历史样本.与An进行了比较。来自西非和中非的coluzzii队列。
结果：本研究报告了An的检测。科鲁兹第一次在肯尼亚。在图尔卡纳县的所有三个时间点都检测到了该物种，从中分析了样品，并通过分类学分析确认了其存在。此外,An之间缺乏很强的种群遗传分化。来自肯尼亚的科鲁兹和来自西非和中非更偏北地区的科鲁兹，表明它们代表了已知物种范围的连接扩展。与目标位点对DDT和拟除虫菊酯的抗性以及对DDT的代谢抗性相关的突变频率高达64％。观察到的变体的分布和频率与An相似。来自西非和中非的coluzzii，但ace-1突变与An中存在的有机磷酸酯和氨基甲酸酯抗性有关。肯尼亚没有西非沿海的coluzzii。
结论：这些发现强调需要在全面和常规的媒介监测中纳入基因组学，以了解疟疾媒介物种的范围。以及它们的杀虫剂抗性状况，为选择有效的媒介控制方法提供信息。
方法：以来自Busia的幼虫为样本的蚊子，Kwale,图尔卡纳,Kirinyaga和Kiambu县，代表肯尼亚疟疾流行的范围，在2019年和2021年，使用根据冈比亚按蚊1000基因组项目第3阶段处理的全基因组测序（WGS）数据进行了分析。如有,WGS包括来自相同地点的历史样本.与An进行了比较。来自西非和中非的coluzzii队列。
结果：本研究报告了An的检测。科鲁兹第一次在肯尼亚。在图尔卡纳县的所有三个时间点都检测到了该物种，从中分析了样品，并通过分类学分析确认了其存在。此外,An之间缺乏很强的种群遗传分化。来自肯尼亚的科鲁兹和来自西非和中非更偏北地区的科鲁兹，表明它们代表了已知物种范围的连接扩展。与目标位点对DDT和拟除虫菊酯的抗性以及对DDT的代谢抗性相关的突变频率高达64％。观察到的变体的分布和频率与An相似。来自西非和中非的coluzzii，但ace-1突变与An中存在的有机磷酸酯和氨基甲酸酯抗性有关。肯尼亚没有西非沿海的coluzzii。
结论：这些发现强调需要在全面和常规的媒介监测中纳入基因组学，以了解疟疾媒介物种的范围。以及它们的杀虫剂抗性状况，为选择有效的媒介控制方法提供信息。
