Effective control of severe fever with thrombocytopenia syndrome in Daishan County, a former epicenter in Zhejiang Province, Southeast China

Abstract

Background: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease with high case fatality rate. In 2016, a series of community-based comprehensive measures were put into effect in Daishan. This study was conducted to explore the change in the epidemiology of SFTS following the implementation of those measures.. Methods: Descriptive and statistical analyses were conducted to characterize the epidemiology of SFTS. Results: In total, 156 cases were reported in Daishan during 2011–2023, with the average annual incidence rate of 66.58 per million. The incidence increased with age, and the case fatality rate was significantly higher among the cases over 65 years (P < 0.050). After the implementation of the community-based comprehensive measures in 2016, the incidence was remarkably declined from 2015 to 2019 (Annual Percent Change [APC] = -39.98, P < 0.001) and remained relatively stable without significant alteration between 2019 and 2023 (APC = 15.77, P = 0.156), which was in contrast to the trends in Zhejiang and Mainland China. The hospital type that was most frequently visited for the initial medical-seeking shifted from type I (59.26 %) in 2011–2016 to type II (56.52 %) in 2017–2023. The time intervals between first-visiting and confirmation, onset and confirmation were shortened in the period of 2017–2023 (P < 0.001). Consequently, the case fatality was insignificantly reduced (8.70 % vs. 20 %, P = 0.084). Conclusions: The community-based comprehensive measures are highly efficacious in the containment of SFTS.

Keywords

• Severe fever with thrombocytopenia syndrome
• China
• Epidemiology
• Incidence
• Case fatality rate