Covid-19 was spreading in the U.S. long before anyone knew

In a stunning interactive feature, the Wall Street Journal reports that based on extensive research and interviews Covid-19 was very likely spreading in the U.S. at the start of the new year, before experts knew it had arrived. In the first week of January, retrospective testing suggests that a small cluster of people in Ohio develop Covid-like symptoms that were likely infections. The people had antibodies for the virus. Screening for travelers to airports from Wuhan, China would begin later, but only at airports in San Francisco, Los Angeles and at New…