Studies of antibodies in blood samples indicate that SARS-CoV-2 was circulating in the US by mid-December 2019. This virus causes COVID-19 infections. Last week, we reported on an Italian study showing antibodies to the virus could be detected before the end of 2019. Researchers found them in blood samples drawn for a cancer study in September, 2019, and stored for analysis. When did the pathogen get to the US?
Finding Out When SARS-2 Reached the US:
The American Red Cross collected blood samples between December 13, 2019, and January 17, 2020. In California, Oregon and Washington, samples from December tested positive for the antibodies (Clinical Infectious Diseases, Nov. 30, 2020). By early January, numerous samples from Connecticut, Iowa, Massachusetts, Michigan, Rhode Island and Wisconsin had antibodies. This was long before health care authorities reported any cases of infection in those areas of the country.
Just 106 samples out of more than 7,000 tested positive. Despite the small proportion, these results seem to show that the virus had spread to this country before December, 2019. That was when Chinese scientists identified it in Wuhan.
