Epidemiological characteristics of hemorrhagic fever with renal syndrome in Yunnan, 2004−2021

  Objective  To understand the epidemiological characteristics of hemorrhagic fever with renal syndrome (HFRS) in Yunnan province from 2004 to 2021.

  Methods  The incidence data of HFRS reported in Yunnan from 2004 to 2021 were obtained from National Notifiable Infectious Diseases Surveillance System for a descriptive epidemiological analysis on the time, area and population distributions of HFRS, and classification of the cases. The spatiotemporal clustering analysis was carried out at county level in the province.

  Results  From 2004 to 2021, a total of 2556 HFRS cases, including 17 deaths, were reported in Yunnan, with an average annual incidence rate of 0.30/100 000 and a case fatality rate of 0.67%. The annual incidence peaked during March-August (spring and summer), Up to 70.81% of the cases were men, 76.72% were aged 16–60 years, and 77.11% were farmers. The global spatial autocorrelation analysis showed that the Moran's I coefficient ranged from 0.010 to 0.319, and only the cases reported during 2011–2021 showed a significant correlation (P＜0.05). High-high clustering areas were mainly in Dali, Chuxiong and Lijiang. In addition, there was a strong negative correlation between the laboratory-confirmed cases and the case fatality rate (r=−0.72, P=0.019), and there was a strong positive correlation between the suspected cases and the case fatality rate (r=0.649, P=0.042), and the case fatality rate was high in areas with less cases.

  Conclusion  The incidence of HFRS in Yunnan reached a relative high level during 2012–2021, the affected areas expanded with obvious spatiotemporal clustering. Population affected became older gradually. It is necessary to promote the implementation of comprehensive prevention and control measures in high-risk areas and improve the cases diagnosis and laboratory testing.