云南省沧源县疟疾再传播影响因素调查

Investigating factors influencing the re-introduction of malaria in Cangyuan County, Yunnan Province

目的调查云南省沧源县开展疟疾再传播影响因素,为沧源县疟疾监测预警和应急响应及消除疟疾措施的制定提供参考依据。方法采集沧源县重点地区居民的末梢血滤纸血膜标本,应用巢式PCR(nested-PCR)法进行传染源的筛查检测;参考《全国消除疟疾监测方案(2015版)》,采用诱蚊灯全通宵捕蚊法、人诱双层叠帐捕蚊法开展媒介调查,分析当地疟疾主要传播媒介种群、密度及其分布规律。结果共筛查检测滤纸血膜标本2 077人份,结果均为阴性;共捕获蚊虫3 152只,分属按蚊属、库蚊属和阿蚊属,总蚊虫密度为32.83只/(灯·夜),其中中华按蚊密度为7.80只/(灯·夜)。传疟媒介以中华按蚊为主,占捕蚊总数的23.8%(749/3 152)。5-10月各月均捕获到中华按蚊,其中7月为中华按蚊密度高峰期,占35.0%(262/749)。人诱双层叠帐捕蚊法未捕获到按蚊。结论沧源县已无本地感染疟疾病例,但传疟媒介持续存在,仍有输入疟疾病例引起再传播的风险。

Objective To investigate factors influencing the re-introduction of malaria in Cangyuan County, Yunnan Province in order to provide a reference for early warnings and rapid responses as part of malaria surveillance and for formulation of measures to eliminate malaria in Cangyuan County. Methods Blood smears were collected from residents in key areas of Cangyuan County. Sources of infection were screened using nested PCR. Based on the National Malaria Elimination and Surveillance Program(2015 edition), vector surveys were conducted by trapping mosquitoes all night with a mosquito lamp and by trapping mosquitoes in a tent trap. The population, density and distribution of the main transmission vectors of malaria in the area were analyzed. Results A total of 2077 blood smears were screened, and all were negative. Traps caught 3,152 mosquitoes belonging to the genera Anopheles, Culex, and Armigeres. The total density of mosquitoes was 32.83 per lamp-trap per night, and the density of Anopheles sinensis was 7.80 per lamp-trap per night. Anopheles sinensis was the dominant vector of malaria, accounting for 23.8% of the total number of mosquitoes caught(749/3152). Anopheles sinensis, a vector of malaria, was caught from May to October. The density of An. sinensis peaked in July, when 35.0% of mosquitoes were caught(262/749). An. mosquitoes were not caught by the tent trap. Conclusion No cases of autochthonous malaria have been reported in Cangyuan County, but transmission vectors remain, and there is a risk of re-introduction caused by cases of imported malaria.