Study suggests virus was in US last December

Tests for SARS-CoV-2 antibodies on archived donated blood samples suggests the virus was in some states by the middle of the month
Australian Associated Press

Coronavirus may have been circulating in the US last December, well before the first COVID-19 case was diagnosed on 19 January, a new analysis of donated blood suggests.

Researchers at the US CDC looked for SARS-CoV-2 antibodies in archived samples of blood donations collected by the American Red Cross from 13 December, 2019 to 17 January 2020 from non-identifiable donors in nine states.