湖南省隆回县疟疾传播媒介调查

An investigation of malaria vectors in Longhui County,Hunan Province

目的调查隆回县疟疾传播媒介,为当地疫情调查处置工作提供参考依据。方法2018年8月中旬,选点至少连续3天开展传疟媒介调查。幼虫调查采用勺捕法,成蚊种类和密度调查采用诱蚊灯通宵诱蚊法和双帐人饵通宵诱捕法,同时清晨入户搜捕按蚊并调查居民蚊帐使用情况。对捕获的成蚊进行形态学及分子生物学鉴定,采用18S rRNA基因为基础的巢式PCR技术检测按蚊体内疟原虫子孢子阳性情况。结果调查点按蚊幼虫密度平均为0.08只/勺;仅捕获中华按蚊成蚊735只,其中人饵帐诱密度平均为0.28只/人·h,畜舍灯诱平均密度为58只/(灯·夜),人房外灯诱平均密度为1.82只/(灯·夜),居民室内未搜捕到按蚊;未检测到疟原虫子孢子。当地居民户均蚊帐使用率为19.05%。结论隆回县传疟媒介单一,为中华按蚊,除畜舍外总体密度较低。但因传疟媒介和输入病例持续存在,流行季节应继续加强该地区的媒介监测、防制和宣教工作。

Objectives To ascertain the malaria vector species and to devise evidence-based recommendations for malaria surveillance and response in Longhui County,Hunan Province.Methods This investigation was conducted at selected sites for at least 3 consecutive days in August 2018.The larval density of Anopheles mosquitoes was determined using a ladle.The adult composition and density were investigated using a light trap and human-baited double-net trap,in addition to a household survey in the early morning.Species identification was based on morphological features and molecular detection.18 SrRNA based nested-PCR was used to detect Plasmodium vivaxin the samples.Results The average density of Anopheles mosquito larvae was 0.08 per ladle.Only Anopheles sinensis was captured in a total of 735 samples.However,no sporozoite-positive mosquitoes were found.The average density based on human bait was 0.28(per personohour),and the average density with a light trap was 58 mosquitoes(per lamponight)in a livestock shed and 1.82 mosquitoes(per lamponight)outside a house.No Anopheles mosquitoes were captured in households.Utilization of mosquito nets was 19.05%.Conclusion An.sinensis was the major malaria vector in the area;it had a low density except in sheds.However,the vector and imported malaria are persistent.Vector surveillance,malaria control,and health education should be enhanced in this county during malaria season to reduce the risk of malaria transmission.