Epidemiology of sfts in Japan

Abstract

Severe fever with thrombocytopenia syndrome (SFTS) is a novel tick-borne disease, which was first reported from China in 2009. Etiological pathogen was identified as SFTS virus (SFTSV), a novel phlebovirus in the family of Bunyaviridae in 2011. Since then, SFTS cases were reported from Korea and Japan. Human infection with SFTSV occur mainly via tick bite, however human-to-human transmission were also suggested by direct contact with SFTS patient’s body fluid such as blood. After 5-14 days of incubation period, a patient develops sudden fever, general malaise, and gastrointestinal symptoms. Laboratory testing usually shows thrombocytopenia, leukocytopenia, elevated lactate dehydrogenase, aminotransferase. Multiorgan failure can be seen severe form of SFTS around 5 days after the onset of illness. Reported case fatality rate ranged about 2-33%. For medical treatment, ribavirin can be used however clinical efficacy has not been established. Given that neither specific vaccine or antivirals is available as of today, to reduce tick bite during outdoor activity, especially in SFTS epidemic area is important to prevent SFTSV infection.