Based on analyzing blood donations from Dec. 13, 2019:
“The 7,389 samples, collected from nine states, were tested for SARS-CoV-2 reactive antibodies. SARS-CoV-2 is the scientific name for the coronavirus that causes Covid-19,” CNN reports. “Of the samples tested, at least 106 were found to have antibodies for SARS-CoV-2, including ones collected from California, Oregon and Washington from Dec. 13 through Dec. 16, 2019.”