HFRS Surveillance in Nanchong,1961-2010

Objective By exploring the epidemic trend and characteristics of hemorrhagic fever with renal syndrome(HFRS) in Nanchong,to provide scientific evidence for its prevention and control.Methods Epidemiological information from 1961 to 2010 was collected,and serological and host animal population monitoring results were analyzed.Results From 1961 to 2010,the incidence rate of HFRS in whole city was 3.92/105,the case fatality rate was 4.09%,and the incidence peaked in 1976-1995,presented two peaks in one year,in which were May to July and October to next January.The disease mainly occurred in 3 municipal districts and neighboring Peng'an county,and in young female farmers.Totally 6881 rats in 9 species were captured,the total rodent density was 10.80%.The dominant rat species in residential areas were Rattus norvegicus,short-tailed shrew and in field was Sichuan Apodemus.The positive rate of rat lung HFRS antigen was 4.75%,the virus mainly carried by Apodemus(8.75%) and Rattus norvegicus(4.30%).The incidence of HFRS was related to the total rat density,the density of wild Apodemus and the density of Rattus norvegicus in residential areas.Conclusion Nanchong was the Apodemus-type based mixed HFRS epidemic area,the epidemic characteristic presented highly sporadic and relative concentrated.Apodemus and Rattus norvegicus are the main host animals and reservior of infection of HFRS in Nanchong city.Integrated prevention should be conducted,with monitoring strengthened.