Seroprevalence and Epidemiological Insights into Severe Fever with Thrombocytopenia Syndrome on Jeju Island, Republic of Korea.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease caused by the SFTS virus, posing significant public health challenges in East Asia. This study aimed to evaluate the seroprevalence of SFTS on Jeju Island, Korea, and to identify the demographic and geographic factors influencing exposure to the virus. A total of 1001 serum samples collected from healthy individuals between 2009 and 2016 were analyzed using a double-antigen enzyme-linked immunosorbent assay. The overall seroprevalence was 1.7%, with slightly higher rates observed in females (2.06%) than in males (1.29%); however, this difference was not statistically significant. Seroprevalence increased with age, peaking at 2.50% in individuals over aged 60 and over. Regional analysis revealed elevated seroprevalence in the eastern coastal areas (4.41%), which was attributed to population density and environmental factors favoring human-tick interactions. These findings suggest that population distribution and land use patterns, rather than altitude alone, significantly affect the exposure of SFTS on Jeju Island. Targeted tick control strategies and public health interventions that focus on high-risk regions and demographics could mitigate SFTS transmission. This study provides valuable insights into the epidemiological characteristics of SFTS and emphasizes the importance of tailored preventive measures in endemic regions.