Abstract: Objective To determine the density and life stages of Aedes, the important dengue vectors, during winter in Jinghong, and to provide a scientific basis for the prevention and control of winter-spring dengue fever in Jinghong. Methods From November 2017 to April 2018, five investigation regions were selected in the eastern, southern, western, northern, and central parts of the downtown of Jinghong, respectively. Using backpack aspirators, the density of adult Aedes mosquitoes was investigated in underground garages, park lawn, hotels, greenhouses, and residential houses in each region. The Breteau index (BI) was used to investigate the breeding and composition of Aedes larvae in water containers in each region. Sediment samples, maybe included eggs of Aedes mosquito, were collected from various Aedes breeding containers in each region. Eggs of Aedes mosquito in the samples were fed in laboratory to adult mosquitoes for identification and counting. The SPSS 19.0 software was used to process the data. The BI value and positive rate of containers for mosquito breeding were compared between different months by χ² test, partition of χ² analysis, and Kruskal-Wallis test. Results A total of 57 adult Aedes mosquitoes were captured, consisting of 11 Ae. aegypti mosquitoes and 46 Ae. albopictus mosquitoes. In those mosquitoes, 46 were captured in residential houses, 9 in park lawn, and 2 in greenhouses. The density of adult Aedes in each month was 9.17, 4.00, 0.00, 0.22, 0.67, and 2.67 mosquitoes/person·hour, respectively, from November to April of the next year, suggesting that the density of adult mosquitoes gradually decreased from November to January of the next year and gradually went up from February to April. In this study, 34 out of 1 500 households and 38 out of 849 water containers were positive for Aedes. The overall BI, container index, and house index were 2.53, 4.48%, and 2.27, respectively. From November to April of the next year, the density of Aedes larvae in each month was 2.80, 0.80, 2.80, 2.40, 2.00, and 4.40 mosquitoes/person·hour, respectively. The main breeding container was bucket, followed by vase. The positive rates of permanent containers, vases, used tires, buckets, waste bottles, and other water containers for Ae. aegypti breeding were 2.42%, 3.56%, 36.36%, 5.63%, 1.82%, and 4.85%, respectively. According to χ² test and partition of χ² analysis, there was a significant difference in the positive rate for Aedes breeding between different types of containers (χ²=29.570, P=0.000). Among those containers, used tires had the highest positive rate. A total of 671 dry sediment samples were collected from various types of water containers. In those samples, 8 were positive for Aedes eggs, yielding a positive rate of 1.19%. A total of 126 Aedes mosquitoes were born from the 8 samples, consisting of 107 (84.92%) Ae. aegypti mosquitoes and 19 (15.08%) Ae. albopictus mosquitoes. The positive rates of vases, used tires, buckets, wastes, and other containers for Aedes eggs were 0.80%, 3.03%, 2.70%, 2.44%, and 1.67%, respectively. There was no significant difference in the positive rate for eggs between various types of containers (H=8.646, P=0.076). Conclusion The two important dengue vectors, Ae. aegypti and Ae. albopictus, were active during winter in Jinghong. Both of them existed in forms of adult, larvae, and egg. The density of adult mosquitoes and larvae started to go up in early April. In order to reduce the density of Aedes mosquitoes in Jinghong, multiple departments and all the residents are recommended to attend the government-led sanitation activities every April that focus on removing larval breeding sites and are accompanied by anti-mosquito spray. In the meanwhile, methods and tools need to be developed to remove and kill Aedes eggs in container sediments.

Key words: Dengue fever, Aedes, Winter, Jinghong

摘要： 目的 掌握景洪市冬季登革热主要媒介伊蚊的密度和存在虫态，为冬春季登革热防控提供科学依据。方法 2017年11月至2018年4月，在景洪市城区按照地理方位选取东、南、西、北、中5个调查点。采用背负式吸蚊器，调查各区域内的地下车库、公园绿地、宾馆、花房、民房等场所的伊蚊成蚊密度；应用布雷图指数（BI）法，调查各区域内容器积水伊蚊幼蚊的孳生和组成状况；采集调查区内各种适宜伊蚊孳生容器内的可能含有伊蚊虫卵的沉淀物，在实验室内将沉淀物加水，使蚊虫卵孵化，饲养至成蚊，鉴定并计数。运用SPSS 19.0软件处理数据，采用χ²检验、χ²分割或Kruskal-Wallis检验对不同月份伊蚊BI、不同类型容器孳生阳性率进行比较。结果 共捕获伊蚊成蚊57只，其中埃及伊蚊11只，白纹伊蚊46只。民房捕获46只，公园绿地捕获9只，花房捕获2只。2017年11月至2018年4月，每月成蚊密度分别为9.17、4.00、0.00、0.22、0.67和2.67只/（人· h）。成蚊密度11月至次年1月呈下降趋势，次年2-4月，成蚊密度逐渐回升。共调查1 500户，阳性34户，积水容器849个，阳性38个，总BI为2.53，总容器指数为4.48%，总房屋指数为2.27。11月至次年4月埃及伊蚊幼蚊BI分别为2.80、0.80、2.80、2.40、2.00和4.40，孳生容器以水桶为主，其次为花瓶；永久性容器、花瓶、废旧轮胎、水桶、废弃瓶/罐和其他积水容器伊蚊幼蚊孳生阳性率分别为2.42%、3.56%、36.36%、5.63%、1.82%和4.85%。经χ²检验、χ²分割分析不同类型容器的孳生率差异有统计学意义（χ²=29.570，P=0.000），废旧轮胎伊蚊阳性率较高。共采集各种类型积水容器积水蒸发后底部干燥沉淀物样本671份，其中虫卵阳性样本8份，阳性率为1.19%。8份样本共羽化伊蚊126只，其中埃及伊蚊107只，占84.92%，白纹伊蚊19只，占15.08%；花瓶、废旧轮胎、水桶、废弃瓶/罐和其他容器虫卵阳性率分别为0.80%、3.03%、2.70%、2.44%和1.67%，各种类型容器虫卵阳性率差异无统计学意义（H=8.646，P=0.076）。结论 景洪市冬季存在登革热主要媒介埃及伊蚊和白纹伊蚊活动，且均以成蚊、幼蚊和虫卵3种虫态存在于自然环境中，成蚊和幼蚊密度4月初开始回升。景洪市应在每年4月，集中开展以政府为主导，多部门联合，全民参与，以清除幼蚊孳生地为主，空间喷洒灭蚊为辅的爱国卫生运动，降低伊蚊密度，同时需研究容器沉淀物中虫卵清除和杀灭方法。

关键词: 登革热, 伊蚊, 冬季, 景洪市