Analysis on the surveillance results of hemorrhagic fever with renal syndrome in Zhejiang Province from 1996 to 2005

Objective The study was conducted to gain insight into the epidemiological characteristics of hemorrhagic fever with renal syndrome(HFRS)in Zhejiang Province in the last ten years so as to provide scientific basis for preventive measures. Methods Descriptive epidemiological approaches were used to analyze the disease, host surveillance was used to investigate the density and virus carried rate of the host animals. Results 17 640 cases of HFRS with 81 deaths was reported from 1996 to 2005 in Zhejiang Province, with the incidence of 3.85/lakh and mortality of 0.46%. The cases were primarily distributed among eastern and western highlands of Zhejiang along Qiantangjiang coast. Hangzhou, Ningbo, Shaoxing, Quzhou and Taizhou were cities that HFRS occurred most frequently, accounting for 76.57% of all cases. Predominating periods were May to July and November to January of the next year, cases accounting for 31.88% and 30.66%, respectively. People aged between 20 and 59 years old were the most easily affected, accounting for 69.48% of the total cases. Farmers were the majority with the rate of 78.95%. The ratio of male to female was 2.61∶1. Apodemus agrarius was the predominating species in the wild and the virus carried rate was 2.98%, serum antibody positive rate being 2.85%. Rattus norvegicus was the indoor predominating species, the virus carried rate being 4.08% and serum antibody positive rate 5.61%. Conclusion HFRS showed an annual declining trend in Zhejiang, while the incidence in some counties still stayed high. Specific control and prevention should be further conducted.