The new coronavirus infected people in the U.S. in mid-December 2019, a few weeks before it was officially identified in China and about a month earlier than public health authorities found the first U.S. case, according to a government study published Monday.
The findings significantly strengthen evidence suggesting the virus was spreading around the world well before public health authorities and researchers became aware, upending initial thinking about how early and quickly it emerged.
Scientists at the U.S. Centers for Disease Control and Prevention found evidence of infection in 106 of 7,389 blood donations collected by the American Red Cross from residents in nine states across the U.S., according to the study published online in the journal Clinical Infectious Diseases.
The scientists based their study on blood samples that the American Red Cross collected between Dec. 13 and Jan. 17 and later sent to the CDC for testing to see if any had antibodies to the new coronavirus, which is named SARS-CoV-2.
“SARS-CoV-2 infections may have been present in the U.S. in December 2019, earlier than previously recognized,” the authors wrote.