北京市部分人群和农产品集散地鼠间汉坦病毒感染的研究

目的了解北京地区鼠间汉坦病毒（HV）感染的可能来源与线索.方法2004年4-5月选取北京城区某大型火车站和郊区某大型农产品贸易集散地,采用夹夜法捕鼠,应用间接ELISA法检测鼠血清IgG抗体;针对HV M和S基因片段设计汉城型病毒（SEOV）特异引物,应用逆转录-聚合酶链反应检测鼠肺中HV,阳性标本直接测序,与GenBank已知序列进行两两比较,对获得序列进行多重比较分析并构建系统发育树.结果共捕获鼠类24只,平均密度3.49%（24/690）,火车站和农产品集散地平均鼠密度分别为1.25%（3/240）和4.67%（21/450）,血清抗体阳性率分别为0.0%和9.5%.优势种分别为小家鼠和褐家鼠,带病毒率分别为14.28%（1/7）和5.89%（1/17）.序列比较结果显示：2份扩增阳性标本M片段核苷酸差异为7.6%,来自火车站的dc501与山东省SD227、河北省Hebei4株亲缘关系较近.来自集贸市场的BjFT01株与GenBank中已注册的其他北京市SEOV株比较,存在一些独特的基因差异,并与海南省HN71株、浙江省K24-E7株多个位点变异类型一致,同源性较高,构成一个支系.而其S片段与韩国80-39株同源性最高（96.4%）,与浙江K24-E7同源性为95 5%.结论北京市人群及农产品集散地鼠类HV感染对肾综合征出血热流行的潜在危险较大,家栖鼠携带并传播的SEOV由上述类似地区从外埠输入到北京的可能性较大,但有待进一步研究.

Investigation on hantaviruses infection in rodents f rom free markets in Beijing areas

OBJECTIVE: In order to find out the factors related to hemorrhagic fever with renal syndrome (HFRS) infection, and to evaluate the probability of ecdemic hantaviruses (HV) infection in rodents in Beijing areas. METHODS: Rodents were collected in a large-scale railway station and a produce market with 'trap nights' method from April to May, 2004. The IgG reacting sera to HV antigen were detected using ELISA. The partial M and S segment of HV from captured rodent lung samples were amplified with RT-PCR. The PCR products were purified and sequenced. BLAST program was then used to perform on nucleotide pairwise alignment with all available sequence in GenBank. The alignment of the multiply nucleotide and the deduced amino acid sequences, together with phylogenetic analysis were completed with DNASTAR software. RESULTS: The average population density was 3.49% (24/690). The overall seroprevalence of HV infection was 8.3% (2/24). RT-PCR positive rates were 8.3% (2/24). The nucleotide sequences of 356 bp region (1958 - 2313) of M segment obtained from 2 samples were all identified to Seoul virus (SEOV), with 7.6% heterogeneity. The dc501 strain from railway station was closely related to SD227 and Hebei4 from Shandong and Hebei provinces respectively. BjFT01 strain from the farm product market had more special nucleotide transitional mutations than other known SEOV from Beijing in GenBank. This strain, together with known HN71 from Hainan province, K24-E7 from Zhejiang province, L99 from Jiangxi province and R22 from Henan province, represented a monophylogentic linkage. CONCLUSION: The higher HV prevalence of rodents in transportation center was the potential and important risk for HFRS epidemic in Beijing. The increasing prevalence of M. musculus should call for attention. It was possible that SEOV in Beijing was imported by infected rodents through vehicles from other provinces.