Ecological And Epidemiological Studies On Rodent Hosts Of Hantavirus In Beijing

Hantavirus (HV) is the causative agent of hemorrhagic fever with renal syndrome (HFRS). In order to discover the reasons of the increasing incidence and identify risk factors of HFRS in Beijing, cross-sectional combined with longitudinal surveys were carried out for infection and genetic diversity of HV in rodent hosts at 9 representative regions of Beijing during 2002 to 2005. Then the associations between the HV prevalence and characteristics of dominant hosts, as well as associations between HV variation and genetic polymorphism of dominant host were studied.Out of 849 rodents captured at 12 different habitats, 6.9% were infected with HV. Rattus norvegicus was the dominant species and Mus musculus also played relative important role in HV transmitting in urban city. Significant differences in infection rates of HV were observed between domestic and forest habitats of rodents. Population dynamics of house rats suggest a correlation between population size and HV prevalence in sites where the host population is relatively isolated.Unconditional multivariate logistic regression analyses were performed with HV infection as the dependent variable and biological characteristics of R. norvegicus population as independent variables. It was shown that adult R.norvegicus had higher HV prevalence than juveniles. Males in the reproduction periods and rats with wounds were more likely to be infected with HV than others.There existed significant differences in HV infection rates among different organs of dominant hosts. The virus-loads in lung tissues of natural infected hosts were significantly higher than those in other tissues. It suggested that lungs were the main organs to be infected by HV, and were more prone to cause HV mutation.