We conducted an epidemiologic study of severe fever with thrombocytopenia syndrome (SFTS) in Japan during 2013–2017. Of 303 cases reported during that period, 133 (44%) were included in this study. The median time between onset of illness and diagnosis of SFTS shortened, from 11.5 to 3.0 days, but the case-fatality rate remained high, at 27%. In 64 patients (48%), a close contact with companion animals was reported within 2 weeks of disease onset. Of these 64 patients, 40 were surveyed further, and we confirmed that 3 had direct contact with body fluids of ill companion animals; 2 had direct contact with the saliva of an ill feral cat or pet dog. These patients reported no history of tick bite, suggesting that ill companion animals might be a source of SFTS virus transmission. Direct contact with the body fluids of ill companion animals should be avoided.

我们在2013-2017年间对日本的血小板减少症候群（SFTS）严重发热进行了流行病学研究。在此期间报告的303例病例中，有133例（44％）被纳入本研究。从发病到确诊SFTS的中位时间从11.5天缩短到3.0天，但病死率仍然很高，为27％。据报道，在64位患者（48％）中，发病后2周内与伴侣动物有密切接触。在这64例患者中，有40例被进一步调查，我们确认3例与病态伴生动物的体液直接接触；其中3例直接接触了患病动物。2人直接接触了一只患病的野生猫或宠物狗的唾液。这些患者没有reported咬史，表明患病的伴侣动物可能是SFTS病毒传播的来源。