[Severe Fever With Thrombocytopenia Syndrome and Associated Encephalopathy]

Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne viral hemorrhagic fever caused by the SFTS virus (SFTSV). Approximately 80 patients are infected annually, mainly in western Japan, and the case fatality rate is >20%. The clinical presentation of SFTS typically includes fever, thrombocytopenia, leukocytopenia, and gastrointestinal symptoms. Localized lymphadenopathy, coagulopathy associated with prolonged activated partial thromboplastin time, muscular symptoms, and neurological abnormalities referred to as SFTS encephalopathy are often observed. Besides tick-borne spread, SFTSV infection is increasingly being transmitted via SFTS-infected cats. Clinicians should remain mindful of this emerging viral infection.