Study on the surveillance of hemorrhagic fever with renal syndrome in national surveillance sites in Liaoning

Objective The present study was conducted to get an insight into the relationship between HFRS incidence rate in crowd and the density, proportion of species and positive rate of HFRS of mice for further effective control of the disease. Methods By setting mouse clamps, a monthly surveillance of the density and positive rate of HFRS of mice was conducted in the three national monitoring sites, Feng Cheng, Xing Cheng and Yu Hong. Indirect immunofluorescence was used to detect the HFRS antigen. Results Two peak values on mouse density were observed in spring and autumn, respectively. The mouse density was 10.83% in May, albeit 0.99% in January. The mouse density was higher in village than outside with statistical significance(x2=181.24, P0.01).The sewer rats were dominant. A total of 555 rat lungs were dissected and 32 positive lungs found, positive rate 5.77%. No significant difference was observed in positive rate of HFRS in four seasons(x2=1.576, P0.05)or in different species of mouse(x2=2.02, P0.05). 418 HFRS cases were reported the three monitoring sites in the year, incidence rate being 28.23/Lakh. The difference in incidence rate was significant among the twelve months(x2=170.42, P0.01). The rise and falls of incidence rate generally coincided with mouse density, and a statistical correlation was presented between the incidence rate and mouse density(r =0.61). Conclusion Incidence rate of HFRS has strong relationship with mouse density. Integrated controlling and prevention, particularly deratization, should be carried out to control the HFRS prevalence.