From July 22-23,3 local COVID-19 cases were reported in Dalian City,Liaoning Province,China.All 3 patients reported that they did not leave Dalian 14 days before the onset of disease and had no COVID-19 case contact h...From July 22-23,3 local COVID-19 cases were reported in Dalian City,Liaoning Province,China.All 3 patients reported that they did not leave Dalian 14 days before the onset of disease and had no COVID-19 case contact history and no foreign personnel contact history.Epidemiological investigation,medical isolation,and nucleic acid detection was immediately carried out in Dalian,and 12 asymptomatic infections were detected in close contacts of Patient 1.Because asymptomatic infections made up a large proportion of total infections,the outbreak was likely observed in the beginning stages.展开更多
基金supported by the National Key Technology R&D Programs of China(Project No.2017ZX10104001,2018ZX 10102001,2018ZX10711001,2018ZX10713002).
文摘From July 22-23,3 local COVID-19 cases were reported in Dalian City,Liaoning Province,China.All 3 patients reported that they did not leave Dalian 14 days before the onset of disease and had no COVID-19 case contact history and no foreign personnel contact history.Epidemiological investigation,medical isolation,and nucleic acid detection was immediately carried out in Dalian,and 12 asymptomatic infections were detected in close contacts of Patient 1.Because asymptomatic infections made up a large proportion of total infections,the outbreak was likely observed in the beginning stages.