Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne zoonosis and SFTS virus is transmitted to humans by tick bites. The aim of this study was to monitor tick population and its SFTS virus infection. During March 2014 to October 2015, ticks were monthly sampled using dry-ice bait trap and flag method from 4 collecting points in Boeun-gun. A total of 16,500 ticks, including 14,646 Haemaphysalis longicornis (88.7%), 1,825 H. flava (11.1%), and 29 Ixodes nipponensis (0.2%), were collected. Ticks were pooled (5,156 ticks in 456 pools) and tested by RT-PCR and nested PCR and the minimum infection rate of ticks was 0.27% (14 pools) consisting of 0.13% H. longicornis (6 pools), 1.19% H. flava (8 pools). This annual surveillance study will be needed for long-term monitoring of ixodid ticks in Korea.

We investigated the distribution of ixodid ticks in severe fever with thrombocytopenia syndrome (SFTS) case reported areas using flagging method from May to November 2014 in Korea. We collected 13,471 ixodid ticks with 2 genera and 3 species. Among them, Genus Haemaphysalis and Ixodes accounted for 99.9% (13,455) and 0.1% (16), respectively. Genus Haemaphysalis consisted of 2 species, H. longicornis (96.2%) and H. flava (3.7%). I. nipponensis was only collected in Genus Ixodes. H. longicornis was the dominant species (over 90%) in most study areas. Ixodid ticks were evenly distributed at various environmental sites, such as residences, hills, grassfields, fields, graves, copses, other sites. The further study on SFTSV infection in ixodid ticks will be needed.

We investigated the prevalence of severe fever with thrombocytopenia- syndrome virus (SFTSV) and geographical distribution of ixodid ticks from 25 regions of the Korea during 2011-2012. We collected 25,940 ixodid ticks with 3 genera and 7 species using dry ice bait trap and flagging. Among them, Genus Haemaphysalis, Ixodes and Amblyomma counted 25,821 (99.5%), 118 (0.5%) and 1 (<0.0%). Genus Haemaphysalis consisted of 4 species, H. longicornis (90.4%), H. flava (9.2%), H. formosensis and H. hystricis (<0.1%). Genus Ixodes consisted of 2 species, I. nippoenesis (0.4%) and I. persulcatus (0.1%). Only one Amblyomma testudinarium was collected. The highly infested sites were grassland (50.1%) and mixed stand forest (20.3%). Minimum infection rate (MIR) of SFTSV in H. longicornis was 0.5% in Korea and this rate was similar to that in China (0.46%). Our results showed that H. longicornis is a major vector of SFTSV and its surveillance will be needed at high risk area.