A newly published study of blood donations collected by the American Red Cross in December 2019 and the first half of January 2020 shows the presence of COVID-19 antibodies in 106 of the samples.
The Red Cross collected the 7,389 samples in nine different U.S. states: California, Wisconsin, Rhode Island, Connecticut, Michigan, Iowa, Oregon, Massachusetts, and Washington. The national Centers for Disease Control and Prevention analyzed the samples.
The findings seem to confirm that there were cases of the virus in the United States before the virus originally was thought to have first been identified in the country on January 19, 2020. The study authors note that the antibodies detected in the samples are specific to COVID-19, not to coronaviruses in general.
The journal Clinical Infectious Diseases released the study.