美去年12月或已有新冠

COVID-19 likely in US in Dec 2019
美去年12月或已有新冠

COVID-19 infections were present in the US as early as mid-December 2019, weeks before it was first identified in China and about a month earlier than the first case was officially confirmed in the US, according to a new study by the US Centers for Disease Control and Prevention (CDC).
根据美国疾病控制和预防中心的一项新研究，新冠病毒感染病例早在2019年12月中旬就已在美国出现，比中国首次发现新冠病毒的时间早了几周，比美国正式确认首例病例早了约一个月。

In the study published in the journal Clinical Infectious Diseases, CDC researchers tested blood samples from 7,389 routine blood donations collected by the American Red Cross from Dec 13, 2019, to Jan 17, 2020, for antibodies specific to the novel coronavirus, known as SARS-CoV-2.
该研究发表于《临床传染病》杂志上，研究显示，疾控中心研究人员对美国红十字会从2019年12月13日至2020年1月17日收集的7389名常规献血者的血液样本进行了检测，以检测新型冠状病毒(即SARS-CoV-2)的特异性抗体。

The researchers found evidence of infection in 106 of the 7,389 blood donations from residents in nine states.
研究人员发现7389份血液样本中的106份含有新冠病毒抗体，这些血液样本来自美国9个州。

The findings suggest that SARS-CoV-2 infections may have been present in the US in mid-December 2019, earlier than the first identified case in the US on Jan 19 this year.
研究结果表明美国新冠感染病例可能在2019年12月中旬就已经出现，早于美国2020年1月19日报告的首例确诊病例的时间。