Changing epidemiology of hemorrhagic fever with renal syndrome in Jiangsu Province, China, 1963-2017

Aim Hemorrhagic fever with renal syndrome (HFRS) remains a serious public health problem in China. Although the number of cases has been decreasing, its incidence shows geographical variability, and risk regions change over time. The aim of this study was to observe temporal and geographic dynamics of HFRS in Jiangsu Province and the impact of demographic characteristics. Subject and Methods Surveillance data of HFRS in Jiangsu Province for the period of 1963-2017 were retrieved and analyzed. We first plotted the overall incidence and created a heat map of the annual incidence rate to visualize the long-term change over the 55-year period by county. The HFRS incidence map was then depicted to show its spatial and geographic distributions. Changes of demographic characteristics, including gender, age, occupation, and region of patients' residence were considered. Results A total of 73,305 confirmed cases of HFRS were reported during the study period and the peak years were in 1964 (13.7 cases/million), 1977 (31.4 cases/million), 1983 (150.9 cases/million), and 1991 (40.1 cases/ million) historically. HFRS affected the southern region of Jiangsu Province first (incidence relatively scattered), then northern regions (relatively high in 1983-1986, 1990-1995), and finally, other parts of the province. Extensive spreading and expanded spatial distribution of risk areas were seen over the past several decades. Most cases occurred in people 16-60 years of age, males, and farmers. Cases involving people over 60 years of age showed a trend of increasing risk. The risk to females over 60 years of age is higher than that of males. Conclusion HFRS incidence showed substantial geographical and temporal variations, which may be associated with rodent migration and urbanization. The detected hotspots of HFRS for future control emphasis are Guanyun, Dafeng, Gaochun, and Sihong Counties. The focus should be on young adult males, farmers, and the elderly.