三峡大坝建成前影响疟疾流行的相关因素分析与监测结果

目的为了掌握疟疾疫情和按蚊密度动态以及影响疟疾流行的相关因素,为今后库区疟疾防治提供基础数据和依据。方法收集、整理三峡库区与疟疾流行的相关资料、建国后疟疾流行概况、媒介种群及分布等资料。1999年建立三峡库区疟疾监测点,监测疟疾疫情和按蚊种群、密度变化动态。结果三峡库区历史上曾有间日疟和恶性疟流行,20世纪60年代后无恶性疟发生,建国后发生过4次大流行,20世纪80年代末控制流行。传疟媒介有嗜人按蚊和中华按蚊。监测结果显示,疟疾疫情稳定,年发病控制在1/万以下;发热病人血检和儿童IFAT检测结果均为阴性;传疟媒介只有中华按蚊,5～9月叮人率在1～9.6只/人·夜之间,牛房密度在9～326只/小时人工之间。结论三峡水库蓄水前,传染源存在,媒介广泛分布,水库建成蓄水后,流速减缓、水面增宽、消落带积水均为按蚊孳生提供了有利条件,开展监测是必要的。

The results of analysis and surveillance on the relevant factors affecting malaria prevalence before the Three Gorge Dam construction

Objective To grasp malaria epidemic,the variation of the density of anopheles and the relevant factors affecting the prevalence of malaria,and provide basis for malaria control in the dam region in the future. Methods To collect and collate the data on malaria epidemic,the general situation about the prevalence of malaria after the foundation of the PRC,the species and distribution on the vector in the dam region. To establish surveillance spots in the dam region to monitor the prevalence of malaria and the variation of the species and density of anopheles in 1999. Results The areas around the Three Gorge Dam had a history of tertian malaria and subtertian malaria epidemic. There was no subtertian malaria after 1960. There were four pandemic after the foundation of the PRC,and the prevalence was controlled in the end of 1980s. The principal transmitting vectors were Anopheles sinensis and An.anthropophagus. The results of surveillance showed that the prevalence was stable,the yearly incidence was less than 1/10000,the blood smears on the fever patients and IFAT examination on children were all negative. The transmission vector was only Anopheles sinensis. The man-biting rate was between 1-1.9/one people -ont night from May to September. The density of anopheles in cow hogpen was 9-326 /h. Conclusion The infection sources existed and the vectors distributed widely before the construction of the Three Gorge Dam. It is necessary to carry out monitoring on malaria because extensive vector distribution,water slowdown,surface widened and eliminate stagnant water-belt formation which provide favorable conditions for the breeding of anopheles after the Three Gorge Dam construction.