深圳市龙岗区蚊虫自然感染流行性乙型脑炎病毒状况调查

目的 研究深圳市龙岗区蚊虫流行性乙型脑炎病毒自然感染状况,为预测该地区乙脑发病趋势及流行强度,制定有效预防控制措施提供科学依据.方法 采用灯诱法捕捉蚊虫标本并进行分类鉴定,以JEV的NS3基因区段设计特异引物,通过实时荧光RT-PCR (real-time RT-PCR)对蚊虫中流行性乙型脑炎病毒进行检测,阳性标本经测序后再在GenBank中进行核苷酸序列的同源性比对.结果 捕获的蚊虫隶属3属5种,致倦库蚊是优势蚊种;1 533只蚊虫分成25批,从3批致倦库蚊标本中检出JEV核酸阳性,阳性率为12％.阳性标本与GenBank中报道的JEV参考株间相应的核苷酸序列同源性达99％以上,均属于JEV Ⅰ型病毒.结论 龙岗区存在着蚊虫自然感染JEV,致倦库蚊是区内乙脑传播的主要蚊媒,有流行人间和畜间流行性乙型脑炎的潜在危险,提示应进一步完善疫苗接种和免疫监测,积极开展消除蚊虫孳生地,灭蚊、防蚊工作,以控制和切断乙脑传播途径.

Survey on natural infection of Japanese encephalitis virus in mosquitoes in Longgang District of Shenzhen City

OBJECTIVE To explore JEV natural infection of captured mosquitoes in Longgang District of Shenzhen City and provide reference for prediction of the prevalence trend and intension of the epidemic encephalitis B.METHODS Lamp baited trap was used to capture mosquitoes.JEV specific primers in NS5 were designed and the Japanese encephalitis virus was identified with real-time RT-PCR.The nucleonic acid detection of positive samples was confirmed by sequencing and the NS3 gene sequence was compared with that published in GenBank.Then the genotype of Japanese encephalitis virus was determined.RESULTS Mosquitoes collected were subjected to 3 genera 5 species and Culex fatigans was dominant population.A total of 1 533 mosquitoes were collected and divided into 25 groups,and 12% were identified positive for viral RNA.The real-time RTPCR assay showed that 3 positive samples were all Culex fatigans.Aligning the sequence with the GenBank database,a maximum nucleotide homology with JEV reference strains in GenBank could be seen,the identity of which was over 99% and all of the three strains belonged to genotype Ⅰ.CONCLUSION The mosquitoes have natural infection of encephalitis B virus in Longgang District and Culex fatigans is the main vector.The results suggest that there might is a potential risk of JEV spread among human and livestock.It is necessary for us to strengthen vaccination monitoring and anti-mosquito campaigns to interrupt the transmission routes.