[Surveillance on hemorrhagic fever with renal syndrome in Jiangsu province from 1996 to 2000].

OBJECTIVE

To analyze the incidence rate, animal hosts, and human inapparent infection rate from surveillance data collected in Jiangsu province from 1996 to 2000 and the risk factors of hemorrhagic fever with renal syndrome (HFRS).

METHODS

Data on the incidence rate was collected from the whole province to describe the epidemiologic characteristics of HFRS. Data on the density of rats, proportion of rats with virus, index of rats with virus and the human inapparent infection rate were collected in special areas according to the standardised protocol in the project.

RESULTS

The incidence rate of HFRS reduced continuously in Jiangsu province, with a 42.17% reduction from 1996 to 2000. The ratio between the incidence rate of autumn-winter peak and spring peak had also reduced. The main host in spring was Rattus norvegicus (with a density of 3.07%), while that in autumn was Apodemus agrarius (with a density of 4.64%). The density of main hosts and mixed species of rats had all reduced during the five years of observation. The proportions of Rattus norvegicus, Apodemus agrarius, Mus musculus with virus were relatively high in spring and autumn. The index of Rattus norvegicus and Mus musculus with virus in spring were 0.025 5 and 0.028 4 respectively, while that of Apodemus agrarius with virus in autumn was 0.030 2. The average human inapparent infection rate was 4.73% in the five years.

CONCLUSION

The incidence rate of HFRS in Jiangsu reduced significantly from 1996 to 2000, but the risk factors still widely existed. Suggesting that the surveillance program needs to be carried out steadily in Jiangsu.