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

  Objective   To strengthen the understanding of the epidemic situation of hemorrhagic fever of renal syndrome (HFRS) in China.

  Methods   The data of reported HFRS cases from 2004 to 2021 was obtained from the the Chinese National Notifiable Disease Surveillance System (NNDSS), and the dynamic change of its epidemiological distributions were analyzed using the descriptive epidemiology method.

  Results   A total of 224396 cases and 2068 deaths were reported in 31 provinces (municipalities and autonomous regions), an overall downward trend were revealed in China in 2004–2021 with an average incidence rate of 0.93 per 100 000 persons, and a case fatality rate of 0.92% respectively. The reported cases showed relative spatiotemporal clustering, 82.54% (185 207 cases) of the total number of reported cases were reported in the top 10 provinces in China. The reported cases peaked twice annually. The spring-summer peak, occurring between April and July, contributed 32.20% of cases, and the fall-winter peak, occurring between October and January of the next year, contributed 47.85% of cases overall. The age distribution of reported cases shifted to the elderly group, the incidence increased significantly in people over 55 years old, and decreased significantly in people 30–45 years old. The proportion of children under 14 years old showed an upward trend. The occupational distribution of cases also fluctuated, and the proportion of cases from unemployed and householders increased significantly, except for farmers who still had a high incidence(67.74%).

  Conclusion   From 2004 to 2021, the number of HFRS cases reported in China fell to a relatively low level, accompanied by significant fluctuations in the number of cases in local areas; the geographic distribution of HFRS has expanded, and reemerged at some areas; the high incidence population continues to shift to the elderly population, and the proportion of children cases had an increasing trend, which should be paid attention to and targeted strategies and measures should be developed.