Original Reports
PANG Wei-long, ZHENG Xiang, GE Jun-hua, CUI Qing-rong, LIU Ying, HU Ya-fei, SHEN Wei-wei, HU Hai-yan, DING Bin-bin, SUN Ji-min, LIN Hai-jiang
Objective To investigate the epidemic situation of hemorrhagic fever with renal syndrome (HFRS) and the surveillance data of host animals in Tiantai county of Zhejiang province, China, and to understand the epidemiological characteristics and changing trend of HFRS. Methods Case surveillance data were collected; the case data in 1984-2003 were collected from the epidemic data archives of Tiantai county, and the case data in 2004-2018 were collected from the China Information System for Disease Control and Prevention. As a national surveillance site, Tiantai county carried out host surveillance and data collection according to national requirements. Excel 2010 and SPSS 17.0 softwares were used to perform a descriptive epidemiological analysis of HFRS epidemic data and surveillance data of host animals, and ArcGIS 10.0 software was used to draw the disease map of townships. Results A total of 6 223 HFRS cases were reported in Tiantai county in 1984-2018, with a mean annual incidence rate of 32.36/100 000; the peak of HFRS epidemic was observed in 1986, with an incidence rate of 206.10/100 000, and then the incidence rate of HFRS decreased rapidly; the incidence rate of HFRS remained at a low level in 2001-2018, with a mean annual incidence rate of 7.01/100 000. The onset seasons of HFRS showed two peaks, with a peak in November to next January (44.08%, 2 743/6 223) and a small epidemic peak in April to June (1 369/6 223, 22.00%). Surveillance data showed that 90.92% (5 658/6 223) of the cases were distributed in 8 plain townships/streets at the Shifeng River Coast of Tiantai county. Most patients were male young adults, and the male/female ratio was 1.66:1 (3 884/2 339). Most patients were farmers (5 553/6 223, 89.23%). The mean density of rodents was 8.87% in 1984-2018, and the mean proportion of virus-carrying rodents was 4.49%. Conclusion The overall incidence rate of HFRS tends to decrease in Tiantai county and maintains at a low level in recent years, and the cases are widely but unevenly distributed and have obvious regional characteristics. Tiantai county is a mixed HFRS epidemic area with Apodemus as the main type of host animal, and there are still high rodent density and virus-carrying rate.