浙江省慈溪市啮齿动物中汉坦病毒分子流行病学研究

Study on the molecular epidemiology of Hantavirus carried by rodent hosts in Cixi, Zhejiang province

目的研究浙江省慈溪市啮齿动物中汉坦病毒（HV）流行情况及病毒型别。方法采用间接免疫荧光法（IFA）检测鼠肺中HV抗原；用逆转录聚合酶链反应（RT-PCR）法扩增阳性样品中HV的部分S片段；构建系统发生树进行系统发生分析及分型。结果在慈溪市肾综合征出血热（HFRS）疫点共捕获啮齿动物243只，在7份鼠肺样品中检测到HV抗原，其中4只为褐家鼠，3只为黄胸鼠，病毒携带率为2．88％。用汉城型病毒（SEOV）特异性引物从6份HV抗原阳性样品中扩增出部分S片段（620～999nt）并测定了序列。对扩增出的部分S片段核苷酸序列分析表明，6株病毒与现有的SEOV有最高的同源性，均为SEOV。用部分S片段核苷酸序列所构建的系统进化树显示，6株病毒构成两个单元支，其中由褐家鼠携带的3株病毒与BjHD01株病毒的亲缘关系最近，分在同一分支，由黄胸鼠携带的3株病毒构成另一分支，与L99、R22及Hb8610株的亲缘关系较近。结论慈溪市的褐家鼠与黄胸鼠分别携带一种不同亚型的SEOV，表现出SEOV在同一地区的遗传多样性，并支持宿主与汉坦病毒共进化的理论。

Objective To collect more data on the epidemiology of hantavirus in rodents in Cixi, Zhejiang province. Methods Rodents were captured in Cixi,where hemorrhagic fever with renal syndrome （HFRS） appeared endemic. Hantavirus antigens in the rat lungs were detected by immunofluorescence assay. Partial S segment sequences were amplified by reverse transciption-polymerase chain reaction （RT- PCR） and then sequenced. The phyologenetic trees were constructed by maximum likelihood method to detect the genetic characteristics of hantavirus. Results A total of 243 rodents were trapped in the epidemic areas,and hantavirus antigens were identified in 7 out of these lung samples （2.88 % ）. Partial S segment sequences （620-999 nt） were recovered from 6 samples and sequenced. Data from phylogenetic analysis of these S segment sequences indicated that all viruses belonged to Seoul virus （SEOV）, despite the origins of sources were either from Rattus norvegicus or from R. flabipectus. These viruses could further be divided into two distinct lineages but the viruses carried by R. norvegicus were different from those carried by R. flabipectus. Conclusion Two distinct lineages of SEOV had been cocirculating in rodents in Cixi.