Clustering of coronavirus disease 2019: a brief report
SUN Qian-lai1, LI Zuo-chao2, TAN Xia-lin2, JIANG Yong-lin2, CHEN Bo-zhong2, LI Mou-yi2, XIAO Qi3, XU Shan-song4, FANG Hong-ying5, WU Qing-chun6, YANG Hao1, HUANG Chao-yang1, LUO Kai-wei1, HE Fang-ling1, HU Shi-xiong1, GAO Li-dong1
1. Hunan Provincial Center for Disease Control and Prevention, Changsha, Hunan 410005, China; 2. Yongzhou Municipal Center for Disease Control and Prevention, Yongzhou, Hunan 425000, China; 3. Lengshuitan District Center for Disease Control and Prevention, Yongzhou, Hunan 425000, China; 4. Lingling District Center for Disease Control and Prevention Yongzhou, Hunan 425006, China; 5. Qiyang County Center for Disease Control and Prevention, Qiyang, Hunan 426100, China; 6. Jiangyong County Center for Disease Control and Prevention, Jiangyong, Hunan 425404, China
Abstract:Objective To preliminarily analyze the latent period, infectious period and transmissibility of coronavirus disease 2019 (COVID-19) through an investigation of a clustering epidemic of COVID-19 in Y city. Methods Field epidemiological method was used to survey the cases and related close contacts. Real time RT-PCR technique was used to detect 2019-nCoV nucleic acid in throat swab samples collected from the respondents. Results A total of 13 confirmed cases and 4 asymptomatic infections were discovered in the clustering epidemic, with the transmission passing through four generations. The average serial interval was 5.08 days, and the average incubation period 5.44 days (ranging between 2 and 10 days). Some confirmed cases were found to be contagious 2 days prior to the onset. There were some asymptomatic infections among the close contacts. Some cases were confirmed after several times of sample testing. Conclusions 2019-nCoV has a high transmissibility. There exist transmission during the incubation period and asymptomatic infection. It is necessary to intensify the prevention and control measures like follow-up and management of close contacts.
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