Ravishankaran Sangamithra, Asokan Aswin, Justin N A Johnson Amala, Surya R Janani, Mathai Manu Thomas, Eapen Alex
ICMR-National Institute of Malaria Research, Field Unit, Chennai, India.
Madras Christian College, Chennai, India.
Am J Trop Med Hyg. 2024 Dec 3;112(2):286-295. doi: 10.4269/ajtmh.24-0243. Print 2025 Feb 5.
Urbanization and microclimate variation in cities can influence mosquito behavior and parasite development, thus affecting malaria transmission. This study investigates how the impact of microclimate variations due to household roof types can aid in the survival of Anopheles stephensi and the development of Plasmodium vivax in an urban slum setting. Understanding these vital environmental interactions is essential for devising effective control strategies to achieve malaria elimination. Anopheles stephensi (F1) mosquitoes were membrane-fed with blood collected from P. vivax-infected patients before (day 0) and during (day 1) antimalarial treatment. The parasite development and mosquito survival were monitored in simulated microclimatic conditions of a variety of household roof types (thatched, asbestos, tiled) against standard laboratory conditions. Mosquito dissections were undertaken to detect oocysts and sporozoites in An. stephensi mosquitoes (oocyst: day 3-5, sporozoites: day 7-11). The maximum number of oocysts were detected in infected mosquitoes in thatched-roof conditions, whereas the largest oocyst was in the asbestos roof type. Circumsporozoite-ELISA results indicated the presence of sporozoites in infected mosquitoes for up to 29 days under standard conditions, 18 days in thatched-roof and asbestos roof conditions, and 14 days in tiled conditions. The univariate binary logistic regression model indicated a significant influence of microclimatic conditions of thatched roofs on parasite development. The Kaplan-Meier survival analysis revealed that the median survival of P. vivax-infected An. stephensi in thatched-roof conditions was 14 days, followed by asbestos (11 days) and tiled (10 days) roof conditions. In conclusion, thatched-roof houses were favorable for the development and survival of P. vivax-infected An. stephensi.
城市中的城市化进程和小气候变化会影响蚊子的行为以及寄生虫的发育，进而影响疟疾传播。本研究调查了家庭屋顶类型导致的小气候变化如何有助于斯氏按蚊的生存以及间日疟原虫在城市贫民窟环境中的发育。了解这些重要的环境相互作用对于制定有效的控制策略以实现疟疾消除至关重要。斯氏按蚊（F1）蚊子在抗疟治疗前（第0天）和治疗期间（第1天）用从间日疟原虫感染患者采集的血液进行膜饲。在各种家庭屋顶类型（茅草屋顶、石棉屋顶、瓷砖屋顶）的模拟小气候条件下，与标准实验室条件相比，监测寄生虫发育和蚊子存活情况。对斯氏按蚊进行解剖以检测卵囊和子孢子（卵囊：第３至５天，子孢子：第７至１１天）。在茅草屋顶条件下感染的蚊子中检测到的卵囊数量最多，而最大的卵囊存在于石棉屋顶类型中。环子孢子酶联免疫吸附测定结果表明，在标准条件下感染的蚊子中存在子孢子的时间长达29天，在茅草屋顶和石棉屋顶条件下为18天，在瓷砖屋顶条件下为14天。单变量二元逻辑回归模型表明茅草屋顶的小气候条件对寄生虫发育有显著影响。Kaplan-Meier生存分析显示，在茅草屋顶条件下，间日疟原虫感染的斯氏按蚊的中位生存期为14天，其次是石棉屋顶（11天）和瓷砖屋顶（10天）条件。总之，茅草屋顶房屋有利于间日疟原虫感染的斯氏按蚊的发育和生存。
