The novel coronavirus was present in the U.S. in December 2019, weeks before health officials first identified infections, according to a new government study.
Conducted by a team that included researchers from the U.S. National Institutes of Health, the study analyzed 24,000 blood samples. The findings suggest that some Americans were infected as early as the middle of December 2019, weeks before the world recognized the spread of the new deadly virus that erupted in the Chinese city of Wuhan.
While the analysis is inconclusive, and some experts remain unconvinced, more federal health officials are accepting a scenario during which small numbers of people in the U.S. were infected with the virus before the world was aware of its spread.
The study, published Tuesday by the Clinical Infectious Diseases journal, is the latest and largest to suggest the virus first appeared in the U.S. earlier than previously known. It found that at least seven people in the U.S. states of Massachusetts, Mississippi, Pennsylvania and Wisconsin were infected earlier than any COVID-19 case was ever reported in those states.