Abstract Background Hard ticks (Ixodidae) are the primary vectors of severe fever with thrombocytopenia syndrome virus (SFTSV), a tick-borne pathogen of increasing public health concern in East Asia. Understanding local vector ecology requires long-term monitoring, particularly in regions where human cases occur but viral prevalence in questing ticks remains unclear. This study conducted multi-year ecological and molecular surveillance of hard ticks and SFTSV in Dangjin-si (City), Chungcheongnam-do (Province), a representative region in west-central ROK. Methods From 2018 to 2024, ticks were collected monthly from April to November across four habitat types (grassland, mountain road, mixed forest, and cemetery) using standardized 24-h CO 2 -baited traps. Specimens were morphologically identified, and a stratified subset was selected for molecular screening after stratification by habitat, species, developmental stage, and sex (for adults). Pooled samples were constructed within each stratum, with up to 50 larvae, 30 nymphs, or 5 sex-separated adults per pool. In total, 36,478 ticks were assembled into 3106 pools and screened for SFTSV by nested reverse transcription (RT)-PCR. Amplification products were evaluated by agarose gel electrophoresis. Results Across the surveillance period, 72,956 ticks (adults, nymphs, and larvae) were collected. Among the collected ticks, three species were identified: Haemaphysalis longicornis (46,269), H. flava (1,143), and Ixodes nipponensis (655). H. longicornis was the most frequently collected and accounted for 63.42% of all adult and nymphal ticks. Tick abundance peaked during 2018–2019 and was highest in grassland habitats. SFTSV was not detected in any of the 3106 pools. Conclusions Although SFTSV was not detected in the screened stratified subset, the persistently high abundance and broad ecological distribution of Haemaphysalis species indicate that Dangjin-si (City) maintains environmental conditions that may support pathogen introduction or amplification. These long-term data provide an ecological baseline for early warning and support targeted surveillance in nearby areas with higher incidence. Integrating ecological, climatic, and epidemiological data, together with multi-pathogen molecular screening, will strengthen One Health-based risk assessment in low-prevalence settings. Graphical Abstract
Shin et al. (Mon,) studied this question.