Covid-19 Likely in U.S. in Mid-December 2019, CDC Scientists Report

In analyzing the blood samples, the CDC scientists found antibodies in 39 samples from California, Oregon and Washington state collected between Dec. 13 and Dec. 16.

The findings suggest there were isolated cases of coronavirus infection on the U.S. West Coast in mid-December, the scientists wrote.

They also found 67 samples with antibodies in Massachusetts, Michigan, Wisconsin or Iowa, and Connecticut or Rhode Island collected between Dec. 30 and Jan. 17.

Research:

Serologic testing of U.S. blood donations to identify SARS-CoV-2-reactive antibodies: December 2019-January 2020