From://www.cbs19.tv/article/news/verify/verify-did-two-percent-of-californians-have-covid-19-in-december-2019/501-7ebeb356-e43e-42ad-abc9-1867d5a8af36
德克萨斯州泰勒--尽管新冠肺炎疫苗已经投入使用，但我们不知道的关于冠状病毒流行的事情仍在不断增加。包括它真正开始的时间。 6park.com
据信，首例新冠肺炎病例是于2019年11月17日在中国武汉发现的。第一个用新冠肺炎的美国人是于2020年1月20日确诊，在华盛顿州。但是，这种新颖的冠状病毒真的需要两个月才能到达我们的海岸吗？如果不是，它在美国传播了多长时间，有多少人在不知情的情况下被感染？ 6park.com
一位观众对此感到担忧，当他被问及加州从2019年12月开始有2%的献血者检测出新冠肺炎抗体呈阳性的说法时。 6park.com
我们回答这个问题的来源是期刊。临床传染病，它由美国传染病学会. 6park.com
它在2020年11月20日发表了一份研究报告。其中，来自多个机构和组织的研究人员对捐赠给美国红十字会的数千份存档血样进行了检查。样本分为两组：一组来自加利福尼亚、俄勒冈州和华盛顿，从2019年12月13日至16日，另一组来自马萨诸塞州、爱荷华州、威斯康星州、密歇根州、罗得岛和康涅狄格州，分别于2019年12月30日至2020年1月17日期间采集。所有的血液都是在美国本土第一例新冠肺炎确诊前捐出的。 6park.com
有关：捐赠：在重症监护病房有父亲的家庭说出了东德克萨斯州的抗体短缺问题。 6park.com
在研究人员重新检测的1,149份血样中，至少有22份含有新冠肺炎抗体，这一比例还不到2%，因此我们可以证实这一说法是正确的。 6park.com
同一周从俄勒冈州和华盛顿州采集的样本中，有2%也发现了新冠肺炎抗体。此外，1月上旬从中西部和东北部重新检测的样本中，约有1%的抗体也呈阳性。 6park.com
有关：什么是不同类型的冠状病毒测试？ 6park.com
加州报告称，其4.6%的人口对新冠肺炎检测呈阳性，但如果在2019年12月，即早在检测之前就有2%的人感染了新冠肺炎，那么感染过这种病毒的人数可能会比我们所知道的要多得多。
VERIFY: Did 2% of Californians have COVID-19 in December 2019?
TYLER, Texas — Even though COVID-19 vaccines are now in use, the list of things we do not know about the coronavirus pandemic keeps growing. That includes when it actually began. 6park.com
The first case of COVID-19 is believed to have been found in Wuhan, China on November 17, 2019. The first American with COVID-19 was diagnosed on January 20, 2020, in Washington State. But did it really take two months for the novel coronavirus to reach our shores? And, if not, how long had it been spreading in the United States, and how many people were infected without knowing? 6park.com
One viewer was concerned about that when he asked about a claim that 2% of blood donations in California from December 2019 tested positive for COVID-19 antibodies. 6park.com
Our source for an answer to this question is the journal Clinical Infectious Diseases, which is published by the Infectious Diseases Society of America. 6park.com
It published a study on November 20, 2020, in which researchers from several agencies and organizations examined thousands of archived blood samples donated to the American Red Cross. The samples came in two sets: one from California, Oregon, and Washington from December 13-16, 2019, and the other from Massachusetts, Iowa, Wisconsin, Michigan, Rhode Island, and Connecticut collected between December 30, 2019, and January 17, 2020. All of the blood was donated before the first diagnosed case of COVID-19 on American soil. 6park.com
RELATED: DONATE: Family with father in ICU speaks out about antibody shortage in East Texas 6park.com
Of the 1,149 blood samples re-tested by the researchers, at least 22 had COVID-19 antibodies, which is just shy of two percent, so we can verify that the claim is true. 6park.com
2% of the samples collected from Oregon and Washington from that same week also showed COVID-19 antibodies. Additionally, about 1% of the samples retested from the Midwest and Northeast from the first half of January tested positive for antibodies, as well. 6park.com
RELATED: What are the different types of coronavirus tests? 6park.com
The State of California reports that 4.6% of its population has tested positive for COVID-19, but if 2% were already infected in December 2019, long before testing was available, the number of people who have had the virus could be much larger than we will ever know.