Epidemiological characteristics of severe fever with thrombocytopenia syndrome (SFTS) in China, 2010-2024: a fifteen-year national surveillance analysis.

Abstract

Background: Severe fever with thrombocytopenia syndrome (SFTS) incidence has risen steadily in China since the disease was first identified in 2009, with both case numbers and the geographic scope of reporting expanding over time. This study analyzed national surveillance data from 2010 to 2024 to characterize the evolving epidemiological patterns of SFTS.

Methods: This retrospective descriptive study included clinically diagnosed and laboratory-confirmed SFTS cases from China Information System for Disease Control and Prevention (CISDCP) (2010-2024). Joinpoint regression was used to analyze incidence trends. Case fatality rate (CFR) differences were assessed by chi-squared or Fisher's exact tests, and the temporal trend was assessed by linear regression.

Results: During 2010-2024, a total of 30 provinces reported 34,055 cases. From 2010 to 2024, the incidence rate of SFTS in China showed a fluctuating upward trend, with an average annual percent change (AAPC) of 43.28% (95% confidence interval [CI]: 43.23%-43.33%;P < 0.01). Most cases were sporadic, with some regional clustering and rapid geographic expansion to previously unaffected areas. The number of reported cases in Anhui Province began to rise rapidly in 2022, making it the province with the highest number of reported cases in China in 2023 and 2024. The average CFR was 4.79%, and the CFR increased with age, reaching 9.15% among those aged 85 years and above.

Conclusions: During the period from 2010 to 2024, SFTS in China exhibited a marked increase in reported incidence and considerable geographical expansion. The disease is no longer confined to traditional high-risk areas; the rapid rise in cases in province such as Anhui suggests a critical need to re-evaluate the ecological and social factors driving its transmission. Although the overall population CFR showed a declining trend, mortality risk among elderly subgroups still needs attention.