云南省边境地区景洪市疟疾媒介调查

Investigation on malaria vectors in Jinghong, a border area in Yunnan Province

目的了解云南省边境地区景洪市疟疾重要传播媒介的按蚊种类、生态习性及其疟原虫子抱子感染情况。方法于2015年在景洪市选取1个历史上疟疾流行高发村曼辉龙村为调查点,6-10月每月捕蚊3d。在调査点东、西、南、北、中5个方位各选择1户人房和畜房,采用灯诱法通宵捕捉按蚊,调查按蚊种群密度;多重PCR检测按蚊胃血,观察其嗜血习性。选择村内和村外各1处采用帐诱法捕捉按蚊,观察按蚊夜间活动规律;采用巢式PCR检测按蚊疟原虫子抱子感染情况。结果共捕获1286只按蚊,属13种,其中中华按蚊936只(占72.8%),微小按蚊188只(占14.6%),为当地按蚊优势蚊种。按蚊的捕获来源地主要为畜房,占85.6%(1101只)。125份中华按蚊胃血多重PCR检测结果显示,人血指数为0,猪血指数为100。中华按蚊村内叮人率为0.6只/(人·h),村外的叮人率为0.2只/(人·h),夜间活动高峰期为20:00-22:00。101只微小按蚊、517只中华按蚊和40只多斑按蚊巢式PCR检测,均未发现疟原虫子抱子感染。结论景洪市按蚊媒介种群以中华按蚊为主,其次为微小按蚊。中华按蚊以嗜家畜血为主。捕获的按蚊中未检测到疟原虫子孢子感染。

Objective To understand the species, ecology of mosquitoes involved in the transmission of malaria in Jinghong, a border area in Yunnan Province. Methods A village called Manghuilong with historically high incidence of malaria along the border area in Jinghong City, Yunnan Province, was selected as a pilot site for the investigation of mosquitoes involved in the transmission of malaria. Mosquitoes were captured with light in 5 living houses and livestock houses evenly located in the village three days a month from June to October in 2015. The mosquito density was recorded in each house. The host species of blood in the stomach of captured mosquitoes were identified by multiple PCR to determine their bloodthirsty habit. The nocturnal activities of mosquitoes were observed by tent trap in and out of the village. The Plasmodium-specific primer-based nest PCR was used to detect sporozoite infection in captured mosquitoes. Results A total of 1 286 mosquitoes belonged to 13 species of Anopheles were captured, including 936 An. sinensis (72.8%) and 188 An. minor (14.6%) as dominant species. The main source of Anopheles was from livestock houses, accounting for 85.6%(1 101). PCR detection on blood from 125 An. sinensis showed that all blood was from pig, no one from human source. The biting incidence of An.sinensis on human in the village was 0.6 per person per hour, and outside village was 0.2 per person per hour. The peak of nocturnal activity was from 8 : 00 pm to 10 : 00 pm. Results of nested PCR on 101 An. minimus, 517 An. sinensis and 40 An. multiflora showed that no Plasmodium sporozoite infection was detected in all captured mosquitoes. Conclusion An. sinensis was the dominant species of mosquito in Jinghong, Yunnan Province, followed by An. minimus. However, An. sinensis mainly feeds on blood of domestic livestock, not on humans. There was no Plasmodium infected mosquito detected in this area.