摘要目的:分析天津市新型冠状病毒肺炎（COVID-19）聚集性疫情病例情况，掌握不同类型聚集性病例发病特征，为COVID-19防控提供流行病学证据和经验。方法:收集截至2020年2月22日天津市全部COVID-19确诊病例的聚集性资料，梳理和分析不同类型聚集性疫情发病特点。结果:截至2月22日，天津市共报告COVID-19聚集性疫情33起，涉及病例115例。聚集性病例分为4类：家庭聚集（28起，71例）、单位聚集（1起，10例）、交通工具（3起，8例）和公共场所（1起，26例），其中单位和公共场所聚集性疫情中的病例又导致了14起家庭聚集性疫情。家庭聚集的续发病例1~7例，中位数为2例。家庭首发病例发病到确诊时间长于续发病例（ Z=-2.406， P=0.016）。公共场所聚集的潜伏期中位数为7 d。家庭、单位和公共场所3类聚集性疫情相比较，病例发病到确诊时间差异有统计学意义（ H=8.843， P=0.012），续发病例发病时间差异有统计学意义（ H=16.607， P=0.000）。 结论:COVID-19疫情监测应特别关注容易发生聚集性疫情场所，及时开展细致的流行病学调查和排查。出现聚集性疫情的场所内部，应及时将密切接触者转至统一的隔离观察点，严格单间管理，避免疫情扩散。部分农村地区防疫意识不强，聚集活动较多，且发病后就诊不及时，在疫情初期应该加强防控的宣传和控制措施。

abstractsObjective:To understand the characteristics of clusters of COVID-19 cases in Tianjin, and provide epidemiological evidence for the prevention and control of COVID-19.Methods:The data of all the COVID-19 cluster cases in Tianjin, reported by 22 February 2020, were collected to analyze the characteristics of different types of the clusters.Results:A total of 115 COVID-19 cases were reported in 33 clusters in Tianjin included 28 family clusters (71 cases), 1 work place cluster (10 cases), 3 transport vehicle clusters (8 cases) and 1 public place cluster (26 cases). Family clusters were caused by the cases from the working place or public place clusters. Numbers of secondary cases of family clusters was between 1 to 7, the median number was 2. The interval from onset to diagnosis for the first case was longer than those of other cases in the familial clusters ( Z=-2.406, P=0.016). The median of incubation period of the public place clusters was 2 days. The intervals from onset to diagnosis were significant different among the family, working place and public place clusters ( H=8.843, P=0.012), and also significant differences in onset time among the secondary cases ( H=16.607, P=0.000). Conclusions:In the surveillance of COVID-19 epidemic, special attention should be paid to places where clustering are prone to occur, and the epidemiological investigation should be carried out timely to confirm the cluster. To prevent the transmission of COVID-19, the close contacts of the patients should be transferred to an assigned observation place on time for single room isolation. The awareness of COVID-19 prevention is low in some rural areas, reflected by many mass gathering activities and delayed medical care seeking after onset. It is necessary to strengthen the health education and take control measures in early period of epidemic.