The first identification and retrospective study of Severe Fever with Thrombocytopenia Syndrome in Japan.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV), a novel bunyavirus reported to be endemic in central and northeastern China. This article describes the first identified patient with SFTS and a retrospective study on SFTS in Japan. METHODS: Virologic and pathologic examinations were performed on the patient's samples. Laboratory diagnosis of SFTS was made by isolation/genome amplification and/or the detection of anti-SFTSV immunoglobulin G antibody in sera. Physicians were alerted to the initial diagnosis and asked whether they had previously treated patients with symptoms similar to those of SFTS. RESULTS: A female patient who died in 2012 received a diagnosis of SFTS. Ten additional patients with SFTS were then retrospectively identified. All patients were aged ≥50 years and lived in western Japan. Six cases were fatal. The ratio of males to females was 8:3. SFTSV was isolated from 8 patients. Phylogenetic analyses indicated that all of the Japanese SFTSV isolates formed a genotype independent to those from China. Most patients showed symptoms due to hemorrhage, possibly because of disseminated intravascular coagulation and/or hemophagocytosis. CONCLUSIONS: SFTS has been endemic to Japan, and SFTSV has been circulating naturally within the country.

Ulcerative Lesions with Hemorrhage in a Patient with Severe Fever with Thrombocytopenia Syndrome Observed via Upper Gastrointestinal Endoscopy.

Severe fever with thrombocytopenia syndrome (SFTS) is a novel bunyavirus infection caused by the SFTS virus (SFTSV, family Bunyaviridae, genus Phlebovirus) with a high case fatality rate. A previously healthy 72-year-old man showed symptoms of fever, general fatigue, and altered consciousness. He was hospitalized for treatment. On day 3, considering the day on which fever appeared first during the disease course as day 0, he had bloody emesis. An emergency upper gastrointestinal endoscopic examination revealed multiple ulcerative lesions with continuously oozing hemorrhage in the stomach. He died on day 7. He was retrospectively diagnosed as having SFTS, Although it was less likely that the gastric ulcerative lesions were directly induced by SFTSV replication, it was evident that hemorrhagic emesis might occur in the patient in association with the pathophysiology of SFTS. The real-time imaging of gastric ulcerative lesions in a patient with SFTS is reported.