The global temperature has significantly risen in the past century. Studies have indicated that higher temperature intensifies malaria transmission in tropical and temperate countries. Temperature fluctuations will have a potential impact on parasite development in the vector Anopheles mosquito. Year-long microclimate temperatures were recorded from a malaria-endemic area, Chennai, India, from September 2021 to August 2022. HOBO data loggers were placed in different vector resting sites including indoor and outdoor roof types. Downloaded temperatures were categorised by season, and the mean temperature was compared with data from the same study area recorded from November 2012 to October 2013. The extrinsic incubation period for Plasmodium falciparum and P. vivax was calculated from longitudinal temperatures recorded during both periods. Vector surveillance was also carried out in the area during the summer season. In general, temperature and daily temperature range (DTR) have increased significantly compared to the 2012–2013 data, especially the DTR of indoor asbestos structures, from 4.30 ℃ to 12.62 ℃ in 2021–2022, unlike the marginal increase observed in thatched and concrete structures. Likewise, the average DTR of outdoor asbestos structures increased from 5.02 ℃ (2012–2013) to 8.76 ℃ (2021–2022) although the increase was marginal in thatched structures and, surprisingly, showed no such changes in concrete structures. The key finding of the extrinsic incubation period (EIP) is that a decreasing trend was observed in 2021–2022 compared to 2012–2013, mainly in indoor asbestos structures from 7.01 to 6.35 days, which negatively correlated with the current observation of an increase in temperature. Vector surveillance undertaken in the summer season revealed the presence of Anopheles breeding in various habitats. Anopheles stephensi could be collected using CDC light traps along with other mosquito species. The microclimate temperature has increased significantly over the years, and mosquitoes are gradually adapting to this rising temperature. Temperature negatively correlates with the extrinsic incubation period of the parasite. As the temperature increases, the development of the parasite in An. stephensi will be faster because of a decrease in EIP, thus requiring relatively fewer days, posing a risk for disease transmission and a hindrance to malaria elimination efforts.

中文翻译：

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气候变化对印度金奈温度变化和疟疾寄生虫外在潜伏期的影响：对其疾病传播潜力的影响

过去一个世纪，全球气温显着上升。研究表明，气温升高会加剧热带和温带国家的疟疾传播。温度波动将对媒介按蚊的寄生虫发育产生潜在影响。2021 年 9 月至 2022 年 8 月，记录了印度金奈疟疾流行区全年的小气候温度。HOBO 数据记录仪被放置在不同的病媒休息地点，包括室内和室外屋顶类型。下载的温度按季节分类，并将平均温度与同一研究区域2012年11月至2013年10月记录的数据进行比较。恶性疟原虫和间日疟原虫的外在潜伏期是根据这两个时期记录的纵向温度计算的。夏季期间还在该地区进行了病媒监测。总体而言，与2012-2013年的数据相比，温度和日温差（DTR）显着增加，特别是室内石棉结构的DTR，从2021-2022年的4.30℃增加到12.62℃，与茅草和混凝土中观察到的边际增加不同结构。同样，室外石棉结构的平均 DTR 从 5.02 ℃（2012-2013 年）增加到 8.76 ℃（2021-2022 年），尽管茅草结构的增加幅度很小，令人惊讶的是，混凝土结构没有出现这种变化。外在潜伏期（EIP）的主要发现是，与 2012-2013 年相比，2021-2022 年观察到了下降趋势，主要是在室内石棉结构中，从 7.01 天到 6.35 天，这与目前观察到的外潜伏期增加呈负相关。温度。夏季进行的病媒监测显示，按蚊在不同的栖息地繁殖。可以使用 CDC 光诱捕器收集史氏按蚊以及其他蚊种。这些年来小气候温度显着升高，蚊子也逐渐适应这种升高的温度。温度与寄生虫的外部潜伏期呈负相关。随着温度升高，寄生虫在An中发育。由于 EIP 减少，斯蒂芬西虫的速度会更快，因此需要的天数相对较少，从而带来疾病传播的风险并阻碍消除疟疾的努力。