Genetic characterization of severe fever with thrombocytopenia syndrome virus in ticks from livestock environments in South Korea.

Introduction: Severe fever with thrombocytopenia syndrome (SFTS), caused by the SFTS virus (SFTSV), is a highly fatal tick-borne zoonosis that poses a substantial public health threat. Although livestock husbandry environments represent important ecological settings for viral maintenance and circulation, molecular surveillance within these settings remains insufficient. Methods: We conducted an annual systematic entomological and molecular survey from March to October between 2023 and 2025 in South Korea, targeting 204 environments adjacent to cattle, horse, deer, goat, and sheep farms. Results: Among 101,006 field-collected ticks, Discussion: Our findings indicate that specific genotype B2 lineages were detected in livestock-adjacent environments, suggesting a potential ecological association with livestock farming. Although the observed sequence conservation may support continued evaluation of conserved S-segment regions for molecular surveillance, the functional significance of the mutations identified in the larval isolate remains to be determined. Continued molecular surveillance may help characterize SFTSV genetic variation in ticks from livestock-associated environments.