A new analysis suggests SARS-CoV-2 may have been present in parts of the US as early as late December 2019, the New York Times reports. It notes, though, that the study's small sample size may make it difficult to distinguish true and false positives.
As they report in the journal Clinical Infectious Diseases, the researchers from the US National Institutes of Health's All of Us research project retrospectively tested more than 24,000 blood samples for SARS-CoV-2 antibodies. Of these samples, 147 had a positive result on one test and nine of those also had a positive result on a second antibody test. Seven of these nine samples were from before there were known COVID-19 cases in participants' states, and one collected in early January 2020 in Illinois that indicates the virus may have been present there in late December 2019, as it takes about two weeks for antibodies to develop.
"It helps us understand a little bit more about the geographic spread of where the virus was in those very early days of the US epidemic," lead author Keri Althoff from the Johns Hopkins Bloomberg School of Public Health tells the Wall Street Journal.