Investigation and analysis on a cluster epidemic of COVID-19 in Yantai City
LIU Tao1, XU Li-fang2, GUO Pei-jun1
1. Yantai Municipal Center for Disease Control and Prevention, Yantai, Shandong 264003, China; 2. Zhaoyuan Center for Disease Control and Prevention, Yantai, Shandong 265400, China
Abstract：Objective To investigate the transmission characteristics and transmission chains of a cluster epidemic caused byCOVID-19,to trace and test close contacts of the identified cases, and to provide evidence for prevention and control of the epidemic. Methods Field epidemiological investigation was conducted according to COVID-19 Prevention and Control Scheme (4th Edition), and respiratory specimens were simultaneously collected for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid detection. Results Twelve cases with positive results for nucleic acid test were involved in the cluster infection, including 4 asymptomatic carriers and 8 confirmed cases. The incubation period of the confirmed cases was generally 3-6 days, with the median of 5 days.The interval between onset of symptoms and visiting a doctor ranged from 1 to 4 days, with the median of 2 days.Among the 8 confirmed cases, 6 were classified as ordinary cases and the other 2 as severe cases. 4 generations of infections were detected in the cluster epidemic, with 1 case in the first generation, 5 cases in the second generation, 2 cases in the third generation and 4 casesin the fourth generation. Conclusions There were clearly identified incubation period and intergeneration relationships in this cluster infection. Risk of interpersonal transmission was present during incubation period of the confirmed cases and also among the asymptomatic carriers.
刘涛, 徐丽芳, 郭培军. 烟台市一起新型冠状病毒肺炎聚集疫情调查分析[J]. 实用预防医学, 2021, 28(3): 266-268.
LIU Tao, XU Li-fang, GUO Pei-jun. Investigation and analysis on a cluster epidemic of COVID-19 in Yantai City. , 2021, 28(3): 266-268.
2021, Vol. 28 
