美國疾病管制與預防中心(CDC)通報美國首起疑似新冠肺炎社區傳播病例
www.wsj.comCovid-19 Likely in U.S. in Mid-December 2019, CDC Scientists ReportThe new coronavirus infected people in the U.S. in mid-December 2019, a few weeks before it was officially identified in China and about a month earlier than public health authorities found the first U.S. case, according to a government study. 美國疾病管制與預防中心(CDC)通報美國首起疑似新冠肺炎社區傳播病例