A study on the epidemic situation and tendency of hemorrhagic fever with renal syndrome in Baoji City

Objective This study was conducted to gain insight into the epidemic characteristics of hemorrhagic fever with renal syndrome in Baoji City and evaluate the efficacy of prevention and control strategies for the development of better countermeasures and effective control of the epidemic．Methods Statistical analysis was done on the data collected about the epidemic situations of hemorrhagic fever with renal syndrome together with those on geographic and geological conditions,weather and hydrological information,and demography from 1995 to 2005 were collected to understand the epidemic trends of the disease and the causes thereof．Vaccination was implemented among the population aged from 16 tO 60 years in the counties with high incidence，and the efficacy of vaccination was analyzed．Results The epidemic of hemorrhagic fever with renal syndrome in Baoji city went through the stages of local sporadic epidemic and wide prevalence．And now it was under preliminary control．The epidemic feature changed from a unimodal peak toward a bimodal peak．Wei River valley was found to be the major epidemic source area with a tendency of increase in the incidence emerging in Taiyuan District of Weibei．Young male peasants were predominantly affected．Immunizations among vulnerable groups in the high-incidence villages and towns of the high-incidence counties were implemented from 2003 to 2005 and the incidence of the epidemic was substantially reduced year by year with a decrease by 76.59％ from 2002 tO 2005.there being a significant decrease in the disease composition in the experimental county (P<0.005)．Conclusion The Baoji city is changing from an Adodemus agrarius Pallas epidemic area of hemorrhagic fever with renal syndrome to a mixed one with Adodemus agrarius Pallas predominance．There is a trend for the epidemic to spread gradually