Abstract: Objective To investigate a cluster epidemic of severe fever with thrombocytopenia syndrome (SFTS) in a county in western Hubei Province, China, so as to provide a basis for formulating prevention and control measures for SFTS. Methods Descriptive epidemiological methods were used to analyze the epidemiological characteristics of the epidemic combined with clinical and laboratory tests, and Fisher’s exact probability method was applied to compare differences in rates of first-episode cases, with a focus on the risk factors for possible transmission. Results There was 1 index case and 4 subsequent cases, with 2 males and 3 females and ages ranging from 54 to 86 years (median: 64 years). The latency period of subsequent cases was 5 to 13 days,with a mean latency period of 7.75 days. Four of the 7 close contacts who swabbed the body of the index case (exposed to the blood) developed the disease,with a significant difference in the prevalence rate between people with different ways of exposure (P=0.003). Conclusions This is the first cluster epidemic of SFTS that is transmissible from human to human in the area. Relevant regulatory authorities should disseminate the knowledge of prevention and control of SFTS among the public and strengthen SFTS diagnosis and treatment training among the medical staff. Thus,disease transmission can be effectively controlled and the case fatality rate can be reduced.

Key words: Severe fever with thrombocytopenia syndrome, Epidemiology, Human-to-human transmission

摘要： 目的 调查鄂西地区某县一起发热伴血小板减少综合征（SFTS）聚集性疫情，为制定SFTS的预防控制措施提供依据。方法 采用描述流行病学方法，结合临床及实验室检测分析此次疫情的流行病学特征，应用Fisher确切概率法比较首发病例密切接触者不同暴露方式罹患率差异，重点分析SFTS可能传播的危险因素。结果 该起疫情首发病例1例，续发病例4例，男性2例，女性3例，年龄在54～86岁，中位数为64岁。续发病例发病潜伏期为5～13 d，平均潜伏期为7.75 d。为首发病例擦拭身体（接触到血液）的7名密切接触者中有4名发病，不同暴露方式的罹患率差异有统计学意义（P=0.003）。结论 本起疫情为该地首起人传人引起的SFTS聚集性疫情。有关部门应对群众普及SFTS防控知识，加强对医护人员SFTS诊疗知识培训，从而有效控制该病的传播，降低病死率。

关键词: 发热伴血小板减少综合征, 流行病学, 人间传播