Severe Fever with Thrombocytopenia Syndrome Virus in Ticks Collected from Humans, South Korea, 2013

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging disease characterized by fever and thrombocytopenia. The syndrome is caused by SFTS virus (SFTSV), a member of the family Bunyaviridae, genus Phlebovirus (1). SFTSV is related to, but distinctly different from, Heartland viruses, which were isolated in the United States (2). The first case of SFTS was reported in China during 2010 (1), and in 2013, SFTSV infections were reported in South Korea and Japan (3–5). In South Korea, the first human case of SFTS was confirmed in May, 2013 (3). Although person-to-person transmission of SFTSV through contact with the blood or mucus of an infected person has been reported (6,7), the virus is primarily transmitted to humans by the bite of SFTSV-infected ticks. The virus has been detected in Haemaphysalis longicornis Neumann (bush tick) and Rhipicephalus microplus Canestrini (southern cattle tick) ticks (1,8). H. longicornis ticks comprise the major population of ticks in the environment and have been considered the main vector for SFTSV (9,10). SFTSV has been detected in H. longicornis ticks collected from the environment by using the dragging or sweeping methods and from mammals. However, to our knowledge, the prevalence of SFTSV in ticks collected from humans has not been reported. To increase our understanding of SFTSV and its possible vectors, we determined the prevalence of SFTSV infection among various ticks collected from humans nationwide in South Korea during May–October 2013.