大连市蚊媒调查及淡色库蚊、三带喙库蚊自然感染流行性乙型脑炎病毒研究

Investigation on Mosquitoes and Study on Natural Infection of the Encephalitis B Virus of Culex Pipiens Pallens and Culex Tritaeniorhynchus in Dalian

[目的]了解大连市蚊虫种类及生态习性及淡色库蚊、三带喙库蚊自然感染流行性乙型脑炎病毒情况。为蚊虫防制提供了生态学依据,为预报流行性乙型脑炎的发生时间和流行强度提供科学依据。[方法]用帐诱法、灯诱法、采集幼虫等方法进行调查,并应用逆转录-聚合酶联反应技术(RT-PCR)进行乙脑病毒鉴定。[结果]大连市捕获蚊虫3属9种。其中,按蚊属1种,伊蚊属4种,库蚊属4种;大连市蚊虫于5月出现,8月达到高峰,9月逐渐减少,10月消失;侵袭人类以淡色库蚊(占47.98%)、东乡伊蚊(占12.15%)和背点伊蚊(占10.41%)为多;夜间以库蚊和按蚊活动为主,白天为白纹伊蚊;不同场所蚊虫密度差异反映出蚊虫的不同嗜血习性,淡色库蚊、凶小库蚊和白纹伊蚊喜嗜人血,淡色库蚊同时喜嗜猪、牛血;三带喙库蚊偏嗜猪血,中华按蚊偏嗜牛血,背点伊蚊和刺扰伊蚊偏嗜猪、牛血;2007年8月中旬首先在三带喙库蚊中检出乙脑病毒,共检测70批次样本,阳性率为4.28%。[结论]淡色库蚊、东乡伊蚊、背点伊蚊是大连市危害人类的主要蚊种,大连市蚊虫自然感染乙脑病毒于8月中下旬开始,三带喙库蚊首先染毒。

[Objective]To investigate the community structure of mosquito and study natural infection of encephalitis B virus of Culex pipiens pallens and Culex tritaeniorhynchus in Dalian. The investigation provided some basic foundations for mosquito control, which can provide scientific support for the prediction of the happening time and prevalence intension of the epidemic encephalitis B virus. [Methods] Human baited net trap,lamp baited trap,larvae collection methods were used and the virus was identified with RT-PCR. [Results]Mosquitoes collected from Dalian were subjected to 3 genera 9 species, one spice of Anopheles, four species of Aedes, four species of Culex. Mosquitoes came forth in May, reached the peak in August,declined gradually from September and disappeared in October. Human were attacked mainly by Culex pipiens pallens（47.98%） ,Ae. （F.） togoi （12.15%） and Ae. （O.） dorsalis （10.41%）. Culex and Anopheles activated at night, Aedes activated at daylight. Different mosquitoes density in different occasion reflect the various features of mosquitoes, Culex pipiens pallens,C. （Ba） modestus, Ae（S.） albopictus profer human blood, C. （C.） pipiens pallens also prefer pig and cow blood,C. （C.） tritaeniorhynchus prefer pig blood,An. （A.）sinensis prefer cow blood,Ae. （O.） dorsalis and Ae. （Aedimorphus） vexans prefer pig and cow blood. The encephalitis B virus was first found on August 16th. Of the 70 groups of samples examined, 4.28 % were male mosquitoes. [Conclusion] Culex pipiens pallens, Ae. （F.） togoi and Ae. （O.） dorsalis were dominant population in this area. The natural infection of encephalitis B virus of mosquitoes began in mid August. Culex tritaeniorhynchus was the first infected species.