Abstract：Objective To investigate the first family cluster of COVID-19 in Lanzhou, so as to provide basis for improving the COVID-19 outbreak prevention capacity. Methods On January 23, the First Hospital of Lanzhou University reported two suspected cases of COVID-19.According to the COVID-19 Epidemiological Investigation Plan ( second edition ) , general information, disease diagnosis and treatment, clinical symptoms, laboratory test results, household environment, exposure history and close contacts were collected to figure out the source of infection and routes of transmission. Results This family cluster lasted 29 days, from January 23 to February 21, reporting nine confirmed cases ( one death ) and one asymptomatic case. There were three imported cases from Wuhan, who were the source of the cluster; and seven secondary cases, who all had close contact with the imported cases during daily life or through having dinners. The secondary attack rate was 41.18% ( 7/17 ) . Among 9 confirmed cases, the incubation period ranged from four to ten days, with a median of nine days. Except for seven secondary cases, 24 close contacts were found and detected negative in the nucleic acid tests. Conclusions The first family cluster of COVID-19 in Lanzhou is caused by the imported cases from Wuhan. All the secondary cases have had dinners and/or had contact with the imported cases, thus they are infected through respiratory droplets and close contact.
王宇红, 张薇, 张晓宇, 马汉平, 王昭君, 张艳, 苏延军, 李红蓉. 兰州市报告的首起新型冠状病毒肺炎家庭聚集性疫情调查[J]. 预防医学, 2020, 32(9): 891-894.
WANG Yuhong, ZHANG Wei, ZHANG Xiaoyu, MA Hanping, WANG Zhaojun, ZHANG Yan, SU Yanjun, LI Hongrong. Epidemiological investigation on the first family cluster of COVID-19 in Lanzhou. Preventive Medicine, 2020, 32(9): 891-894.
