Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya.
International Center of Excellence for Malaria Research, Tom Mboya University, College of Maseno University, Homa Bay, Kenya.
J Med Entomol. 2023 Jan 12;60(1):202-212. doi: 10.1093/jme/tjac168.
Several sub-Saharan African countries rely on irrigation for food production. This study examined the impact of environmental modifications resulting from irrigation on the ecology of aquatic stages of malaria vectors in a semi-arid region of western Kenya. Mosquito larvae were collected from irrigated and non-irrigated ecosystems during seasonal cross-sectional and monthly longitudinal studies to assess habitat availability, stability, and productivity of anophelines in temporary, semipermanent, and permanent habitats during the dry and wet seasons. The duration of habitat stability was also compared between selected habitats. Emergence traps were used to determine the daily production of female adult mosquitoes from different habitat types. Malaria vectors were morphologically identified and sibling species subjected to molecular analysis. Data was statistically compared between the two ecosystems. After aggregating the data, the overall malaria vector productivity for habitats in the two ecosystems was estimated. Immatures of the malaria vector (Anopheles arabiensis) Patton (Diptera: Culicidae) comprised 98.3% of the Anopheles in both the irrigated and non-irrigated habitats. The irrigated ecosystem had the most habitats, higher larval densities, and produced 85.8% of emerged adult females. These results showed that irrigation provided conditions that increased habitat availability, stability, and diversity, consequently increasing the An. arabiensis production and potential risk of malaria transmission throughout the year. The irrigated ecosystems increased the number of habitats suitable for Anopheles breeding by about 3-fold compared to non-irrigated ecosystems. These results suggest that water management in the irrigation systems of western Kenya would serve as an effective method for malaria vector control.
撒哈拉以南的几个非洲国家依赖灌溉来生产粮食。本研究考察了灌溉对肯尼亚西部半干旱地区疟疾媒介水生阶段生态的环境变化的影响。在季节性横断面和每月纵向研究中，从灌溉和非灌溉生态系统中收集了蚊子幼虫，以评估在旱季和雨季临时、半永久性和永久性栖息地中按蚊的栖息地可得性、稳定性和生产力。还比较了选定栖息地之间的栖息地稳定性持续时间。使用出现陷阱来确定不同栖息地类型的雌性成年蚊子的日产量。通过形态学鉴定疟蚊，并对姐妹种进行分子分析。在两个生态系统之间对数据进行了统计学比较。在对数据进行聚合后，估计了两个生态系统中不同栖息地类型的疟疾媒介的总体生产力。两种生态系统中的疟蚊（Anopheles arabiensis）幼虫占所有幼虫的 98.3%。灌溉生态系统的栖息地数量最多，幼虫密度最高，产生的成年雌性成虫数量占 85.8%。这些结果表明，灌溉提供了增加栖息地可得性、稳定性和多样性的条件，从而增加了全年传播疟疾的阿拉伯按蚊的数量和潜在风险。与非灌溉生态系统相比，灌溉生态系统增加了大约 3 倍适合疟蚊繁殖的栖息地数量。这些结果表明，肯尼亚西部灌溉系统的水资源管理将成为控制疟疾媒介的有效方法。
