Surveillance on hemorrhagic fever with renal syndrome in Qingdao City in 2005

Objective The present study was conducted to investigate the epidemic characteristics of hemorrhagic fever with renal syndrome(HFRS) and direct the future prevention and control. Methods Surveillance data of HFRS in Qingdao City in 2005 were analyzed. Results The morbidity of HFRS was 2.80/lakh and the fatality rate was 2.82% in Qingdao City. The seasonal distribution of HFRS appeared two peaks, mainly focused in autumn and winter. The number of the cases with HFRS during the two seasonal peaks accounted for 91.08% of all the cases with HFRS. 96.24% of cases were reported from the five counties. Morbidity in Jiaonan was 7.63/lakh, the highest. The onset ages ranged from 10 to 85 years old, and 88.73% of the cases were at the age of 20 to 60 years old. Peasants accounted for 79.81%. The ratio of male to female was 2.67∶1. Rodent capture rate was 1.00%. Mus musculus and Suncus murinus were found to carry antigen with direct immunofluorescent antibody assay, and the positive rate was 1.41%. In residential areas, Mus musculus (50.53%) and Rattus norvegicus (41.05%) were the main species of mice. Apodemus agrarius was the wild dominant species (36.17%). The virus-carried rate of mice in residential areas and fields was 0 and 4.26%, respectively. Conclusion The morbidity and mortality rate of HFRS significantly declined in Qingdao City in 2005, but the morbidity was comparative high in some areas where more attention should be paid to the prevention and control of the disease.