Objective: To investigate the distribution patterns of mosquitoes, midges and related arboviruses in Sichuan province. Methods: Blood-sucking insects were collected from houses and pens, using the ultraviolet lights. Mosquito samples were classified according to morphologic characteristics and then stored at liquid nitrogen. All samples were incubated with BHK-21 and C6/36 cells for virus isolation and then detected for their viral genes. Sequences of the virus were identified and analyzed by molecular biological software, such as BioEdit 7.0.5.3, MEGA 6.0. Results: In total, 17 019 mosquitoes from 3 genera and 4 species and 12 700 midges were collected from the southeast regions of Sichuan province in 2016 and 2017. Among them, 79.4% (13 519/17 019) belonged to Culex tritaeniorhynchus with 11.1% (1 897/17 019) as Armigeres subalbatus, 5.5% (930/17 019) were Anopheles sinensis and 4.0% (673/17 019) were Anopheles sinensis 3 virus strains that isolated from Culex tritaeniorhynchus were identified as typeⅠ Japanese encephalitis virus. Seven pools of mosquitoes isolated from Hejiang county were identified Japanese encephalitis virus gene positive through PCR amplification. With 4 pool midges were detected positive for Akabane virus through PCR gene amplification while midges samples didn't have virus isolates. Conclusions: Culex tritaeniorhynchus appeared the predominant species in the southeast regions of Sichuan. Japanese encephalitis virus transmitted by mosquitoes and Akabane virus by midges were prevalent in southeast Sichuan province.
目的： 了解四川省的蚊、蠓以及相关虫媒病毒种类及分布。 方法： 在自然界使用灯诱法采集吸血昆虫标本，形态学分类后分装，液氮保存备用。蚊虫、蠓虫研磨上清液接种BHK-21细胞和C6/36细胞进行病毒分离和病毒基因检测。使用BioEdit 7.0.5.3、MEGA 6.0等软件对病毒序列进行分子生物学特征分析。 结果： 2016－2017年在四川省东南部3个县的7个自然村共采集到3属4种蚊虫17 019只，蠓虫12 700只。三带喙库蚊占蚊虫采集总数的79.4%（13 519/17 019），其次为骚扰阿蚊（11.1%，1 897/17 019），致倦库蚊占采集蚊虫标本总数的5.5%（930/17 019）；中华按蚊最少（4.0%，673/17 019）。蚊虫标本接种组织细胞后，在合江县采集的三带喙库蚊标本获得3株可以稳定传代的病毒分离株，经分子生物学实验鉴定为基因Ⅰ型流行性乙型脑炎（乙脑）病毒，在合江县采集的7批蚊虫中检测到乙脑病毒基因阳性。蠓虫标本接种细胞后未获得病毒分离物，在合江县采集的4批蠓虫标本经分子生物学检测，显示阿卡斑病毒基因阳性。 结论： 三带喙库蚊是四川省东南部3县的优势蚊种，四川省东南部存在经蚊虫传播的乙脑病毒及以蠓虫为媒介的阿卡斑病毒。.
Keywords: Akabane virus; Japanese encephalitis virus; Midge; Mosquito.