中国-老挝登革热重点地区埃及伊蚊孳生习性及杀虫剂抗性水平比较研究

A comparative study of breeding habits and insecticide resistance of Aedes aegypti in key areas of dengue fever in China and Laos

目的了解和比较中国-老挝登革热重点地区埃及伊蚊孳生习性及杀虫剂抗性水平,指导科学合理选用杀虫剂。方法分别在中国云南省勐腊和勐海县及老挝琅勃拉邦市采用布雷图指数(BI)法调查居民区所有积水容器,采集阳性容器内的幼蚊并鉴定蚊种;采集的埃及伊蚊幼虫在实验室饲养至成蚊,采用成蚊滤纸接触筒法,测定其对常用杀虫剂的抗药性水平。结果共调查居民800户,伊蚊阳性78户,发现7类积水容器或积水(以下统称积水容器)共1194个,阳性109个,BI均值为13.63;积水容器类型以水桶最多(37.10%);伊蚊孳生阳性容器以其他暂时性容器最多(30.28%);白纹伊蚊孳生阳性容器18个(16.51%),埃及伊蚊孳生阳性容器91个(83.49%)。中国勐腊县埃及伊蚊成蚊对3.20%氯菊酯、0.08%高效氯氟氰菊酯、0.27%高效氯氰菊酯、0.20%溴氰菊酯、0.25%马拉硫磷、0.25%杀螟硫磷和0.03%残杀威,24 h死亡率分别为3.51%、5.69%、4.07%、63.45%、97.86%、100%和80.65%;中国勐海县埃及伊蚊成蚊对上述7种杀虫剂24 h死亡率分别为8.57%、2.86%、3.23%、8.24%、92.51%、100%和90.96%;老挝琅勃拉邦市埃及伊蚊成蚊对3.20%氯菊酯、0.08%高效氯氟氰菊酯、0.20%溴氰菊酯、0.25%杀螟硫磷和0.03%残杀威,24 h死亡率分别为67.53%、25.47%、72.63%、100%和98.82%。结论中国与老挝埃及伊蚊主要孳生场所存在差异,老挝以水池为主,而中国以水桶、其他暂时性容器为主。埃及伊蚊成蚊对多种拟除虫菊酯类杀虫剂均产生了不同程度的抗药性,中国埃及伊蚊抗性程度比老挝高。对有机磷类杀虫剂和氨基甲酸酯类杀虫剂均为可能抗性或敏感。应加强埃及伊蚊种群密度及其杀虫剂抗药性监测,合理选用杀虫剂种类开展灭蚊控制。

Objective To compare the breeding habits and insecticide resistance level of Aedes aegypti in key areas of dengue fever in China and Laos,and to guide scientific and rational selection of insecticides.Methods The Breteau index(BI)method was used to examine all water containers in residential areas in Mengla and Menghai counties of China and Luang Prabang city of Laos.Mosquito larvae in positive containers were collected and identified.The collected Ae.aegypti larvae were reared to adult mosquitoes in the laboratory,followed by testing their resistance levels to common insecticides using the filter paper contact method.Results A total of 800 households were investigated,of which 78 households were positive for Aedes mosquitoes.A total of 1194 water containers or ponding(hereinafter referred to as containers)of seven types were found,with 109 being positive.The mean BI was 13.63.Buckets were the most common type of water containers,accounting for 37.10%.The most common Aedes positive containers belonged to other temporary containers,accounting for 30.28%.There were 18 containers(16.51%)positive for Ae.albopictus mosquitoes,and 91(83.49%)positive for Ae.aegypti.The 24-hour mortality rates of Ae.aegypti in Mengla county exposed to 3.20%permethrin,0.08%lambda-cyhalothrin,0.27%beta-cypermethrin,0.20%deltamethrin,0.25%malathion,0.25%fenitrothion,and 0.03%propoxur were 3.51%,5.69%,4.07%,63.45%,97.86%,100%,and 80.65%,respectively.The 24-hour mortality rates of Ae.aegypti in Menghai county exposed to the above-mentioned insecticides were 8.57%,2.86%,3.23%,8.24%,92.51%,100%,and 90.96%,respectively.The 24-hour mortality rates of Ae.aegypti in Luang Prabang city exposed to 3.20%permethrin,0.08%lambda-cyhalothrin,0.20%deltamethrin,0.25%fenitrothion,and 0.03%propoxur were 67.53%,25.47%,72.63%,100%,and 98.82%,respectively.Conclusions The main breeding sites of Ae.aegypti differ in China and Laos,which are water pools in Laos while bucket and other temporary containers in China.In both regions,adult Ae.aegypti mosquitoes have developed different levels of resistance to various pyrethroid insecticides,with higher resistance in China,while they are possibly resistant or sensitive to organophosphorus and carbamate insecticides.We suggest strengthening the surveillance of the population density and insecticide resistance of Ae.aegypti and selecting rational insecticides to control mosquitoes.