Covid-19 may have been in US weeks earlier than initially thought, study finds

Covid-19 may have been present in the United States weeks earlier than scientists and public health officials previously thought and before the first cases were publicly reported in China, a new study suggests.

The first Covid-19 case was officially confirmed on January 21 in the state of Washington, a patient who recently had returned from Wuhan. Scientists from the US CDC have published their research in the peer-reviewed medical journal 'Clinical Infectious Diseases, suggesting that "SARS-CoV-2 infections may have been present in the U.S. in December 2019, earlier than previously recognized." Their conclusion was based off routine blood samples collected by the Red Cross between December 13 and January 17, 2019, from residents of nine states.