目的分析某中学1起甲型H3流感聚集性疫情的流行特征,为更好地开展防控工作提供参考依据。方法通过该中学医务室学生缺勤缺课登记资料搜索因发热或感冒等缺勤缺课的学生,采用《流感样病例聚集性发病调查一览表》对搜索到的学生逐个进行调查,确认流感样病例;对发病3 d内的流感样病例采集鼻咽拭子样本进行流感病毒核酸检测。结果该起疫情首发病例发病时间为4月13日,末例病例发病时间为4月28日,历时16 d,累计发病42例,罹患率为1.71%(42/2 462)。男生26例,女生16例,男女性别比为1.63∶1;病例年龄为13~17岁,平均年龄14岁;发病集中在初一(21例,占50.0%)和初二年级(21例,占50.0%)。采集32例病例的鼻咽拭子样本,检出8份为流感病毒甲型H3阳性。结论该起疫情为发生在该中学初一、初二年级的甲型H3流感聚集性疫情。未能及时发现并报告疫情、未能及时有效采取隔离措施是发生此次聚集性疫情的主要原因。 Objective To analyze the epidemiological characteristics of a cluster of Influenza A (H1N1) outbreaks in a middle school and provide a reference for better prevention and control. Methods Students who missed the absent attendance due to fever or flu were enrolled in this study. The students were searched one by one to confirm the flu-like cases. Nasopharyngeal swab samples were collected for influenza virus nucleic acid testing for influenza-like cases within 3 days of onset. Results The onset time of the initial outbreak was April 13, the last case was April 28, and lasted for 16 days. The cumulative incidence was 42 cases with an attack rate of 1.71% (42/2 462). There were 26 males and 16 females, with a sex ratio of 1.63:1. The age ranged from 13 to 17 years with a mean age of 14 years. The incidence was mainly in the first stage (21 cases, 50.0%) and the second year (21 cases, Accounting for 50.0%). Thirty-two nasopharyngeal swab samples were collected and 8 samples were positive for influenza A (H3N1). Conclusions The outbreak is a cluster epidemic of Influenza A (H3 H3) occurring in the first and second grades of the middle school. The failure to detect and report the outbreak in time and the failure to timely and effectively adopt isolation measures are the major causes of the outbreak.