摘要
On October 10,2020,3 cases of coronavirus disease 2019(COVID-19)were detected via routine preadmission nucleic acid screening of inpatients and their visitors at Qingdao Central Hospital.The 3 cases were all related to the Qingdao Chest Hospital.An additional 9 cases were discovered and confirmed through tracing and testing contacts of the 3 initial cases.Viral isolates from all 12 cases were found to have high degrees of genetic homology with the viral isolate from a dockworker at Qingdao Port,referred to as Patient A in this report.A joint investigation team was formed to determine the source of infection and the scale of the outbreak,and to prevent further spread of the virus.
