School of Biological Sciences, Department of Zoology, University of Nairobi, Nairobi, Kenya.
Department of Biological Sciences, Chuka University, Chuka, Kenya.
Parasit Vectors. 2020 Oct 1;13(1):499. doi: 10.1186/s13071-020-04378-7.
Aedes aegypti is an efficient vector of several arboviruses of public health importance, including Zika and dengue. Currently vector management is the only available avenue for disease control. Development of efficient vector control strategies requires a thorough understanding of vector ecology. In this study, we identified households that are consistently productive for Ae. aegypti pupae and determined the ecological and socio-demographic factors associated with the persistence and abundance of pupae in households in rural and urban Kenya.
We collected socio-demographic, environmental and entomological data monthly from July 2014 to June 2018 from 80 households across four sites in Kenya. Pupae count data were collected via entomological surveillance of households and paired with socio-demographic and environmental data. We calculated pupal persistence within a household as the number of months of pupal presence within a year. We used spatially explicit generalized additive mixed models (GAMMs) to identify the risk factors for pupal abundance, and a logistic regression to identify the risk factors for pupal persistence in households.
The median number of months of pupal presence observed in households was 4 and ranged from 0 to 35 months. We identified pupal persistence in 85 house-years. The strongest risk factors for high pupal abundance were the presence of bushes or tall grass in the peri-domicile area (OR: 1.60, 95% CI: 1.13-2.28), open eaves (OR: 2.57, 95% CI: 1.33-4.95) and high habitat counts (OR: 1.42, 95% CI: 1.21-1.66). The main risk factors for pupal persistence were the presence of bushes or tall grass in the peri-domicile (OR: 4.20, 95% CI: 1.42-12.46) and high number of breeding sites (OR: 2.17, 95% CI: 1.03-4.58).
We observed Ae. aegypti pupal persistence at the household level in urban and rural and in coastal and inland Kenya. High counts of potential breeding containers, vegetation in the peri-domicile area and the presence of eaves were strongly associated with increased risk of pupal persistence and abundance. Targeting households that exhibit pupal persistence alongside the risk factors for pupal abundance in vector control interventions may result in more efficient use of limited resources.
埃及伊蚊是几种具有公共卫生重要性的虫媒病毒的有效载体，包括寨卡病毒和登革热病毒。目前，病媒控制是疾病控制的唯一可行途径。开发有效的病媒控制策略需要对病媒生态学有透彻的了解。在这项研究中，我们确定了始终能产生埃及伊蚊蛹的家庭，并确定了与肯尼亚农村和城市家庭中蛹的持续存在和丰度相关的生态和社会人口因素。
我们从 2014 年 7 月至 2018 年 6 月，每月从肯尼亚四个地点的 80 户家庭收集社会人口、环境和昆虫学数据。通过家庭的昆虫学监测收集蛹计数数据，并与社会人口和环境数据配对。我们将家庭内的蛹持续存在定义为一年内蛹存在的月数。我们使用空间显式广义加性混合模型（GAMM）来确定蛹丰度的危险因素，并使用逻辑回归来确定家庭中蛹持续存在的危险因素。
家庭中观察到的蛹存在月数的中位数为 4 个月，范围为 0 至 35 个月。我们在 85 个房屋年内发现了蛹的持续存在。高蛹丰度的最强危险因素是围生境区域有灌木或高草（OR：1.60，95%CI：1.13-2.28）、敞口屋檐（OR：2.57，95%CI：1.33-4.95）和高栖息地计数（OR：1.42，95%CI：1.21-1.66）。蛹持续存在的主要危险因素是围生境区域有灌木或高草（OR：4.20，95%CI：1.42-12.46）和高繁殖地点数量（OR：2.17，95%CI：1.03-4.58）。
我们在肯尼亚城乡、沿海和内陆观察到埃及伊蚊蛹在家庭层面的持续存在。潜在繁殖容器数量高、围生境区域植被和屋檐的存在与增加蛹持续存在和丰度的风险密切相关。在病媒控制干预措施中，针对表现出蛹持续存在的家庭，并针对蛹丰度的危险因素进行靶向干预，可能会更有效地利用有限的资源。
