Abstract
OBJECTIVES: Severe fever with thrombocytopenia syndrome (SFTS) is a notifiable category III infectious disease caused by the SFTS virus (Dabie bandavirus), with a high fatality rate of 18.5% in the Republic of Korea (ROK). Further clinical studies are required to establish evidence for patient management in the absence of vaccines or antiviral therapies. However, as approximately 200 sporadic cases occur annually nationwide, obtaining a sufficient sample size for research remains challenging. This study established a multicenter cohort across 23 hospitals to investigate the diagnostic processes, treatment statuses, and clinico-epidemiological characteristics of patients with SFTS in ROK. METHODS: This multicenter registry study was conducted between March 2022 and December 2024 across 23 hospitals and included both prospective and retrospective cohorts. Clinical data and biospecimens from the enrolled patients were collected and analyzed to evaluate diagnostic and therapeutic patterns. RESULTS: A total of 311 patients (100 prospective; 211 retrospective) were enrolled, accounting for 15% of all reported cases nationwide (n=2,065). Laboratory confirmation was achieved in 98.4% (306/311) of patients through regional public health laboratories. The median interval from symptom onset to diagnosis was 7 days (interquartile range [IQR], 4-10 days), and 3 days (IQR 1-5 days) from hospital admission to diagnosis. Among confirmed cases, 52.1% (162/311) received treatment, most commonly plasmapheresis, followed by steroids, ribavirin, and intravenous immunoglobulin. CONCLUSIONS: This multicenter cohort study characterized the diagnostic and therapeutic patterns of patients with SFTS in ROK. The findings provide essential data for the development of diagnostic tools and therapeutic strategies and highlight the importance of continued multicenter clinical research on SFTS.