Abstract:

Objective To get an insight into the dynamics of mosquitoes in the process of the hydraulic cascade development in the Yichang section of the Three Gorges Area, providing important background information for medical assessment of the environment for large-scale water control project. Methods The data on mosquitoes in this area recorded since 1959 with those from 1971 to 2009 collected through investigation were studied and analyzed. The density of mosquitoes was surveyed with the labor-hour method. Results There was an overall downward trend in the density of mosquitoes in the Yichang section of the Three Gorges reservoir area in different periods with a higher density in barns than in houses. The mosquito density during 1971 to 1980 reached the highest value (239.0 per house/hour) compared with the density in the periods before and after the time. From 2001 to 2009, when the second and third stage construction of the Three Gorges Project was completed, the density fell to historic lows (75.2 per house/hour). There were great changes in the composition of mosquito species in both the barns and the houses, which was related to the alteration of the environment where mosquitoes bred, and explained the epidemic features of the vector-borne diseases. Conclusion Currently the density of mosquitoes in the Yichang section of the Three Gorges reservoir area has fallen to historic lows with no significant fluctuations seen in the incidence of the related diseases in the area. The hydropower projects do not show a significant impact on them.

Key words: Three Gorges area, Mosquito, Changing trend

摘要：

目的 掌握三峡库区宜昌段水利工程梯级开发过程中的蚊类变动趋势，为大型水利枢纽工程环境的医学评估提供重要的背景资料。方法 研究整理与分析本单位1959年以来所调查的库区蚊类记录，通过调查补充1971－2009年数据，用人工小时法调查蚊密度。结果 三峡库区宜昌段不同时期蚊密度总体上呈下降趋势，牛房蚊密度高于人房。1971－1980年蚊密度较前后临近时段达到最高值〔239.0只/(间·人工小时)〕。2001－2009年，三峡工程完成二、三期建设，全线竣工，该时段蚊密度降至历史最低点〔75.2只/(间·人工小时)〕。人房、牛房蚊种构成均有很大变化，这种动态变化与蚊虫的孳生环境改变有关，也决定了病媒传染病的流行特征。结论 三峡库区宜昌段蚊密度目前已降至历史最低点，相关疾病发病率未见异常波动，库区水利工程兴建对其未呈现显著影响。

关键词: 三峡库区宜昌段, 蚊类, 变动趋势