New research has found that the COVID-19 virus was circulating in at least five states for months before the first case was officially reported in the United States.
According to a National Institutes of Health study published Tuesday, June 15 in the Clinical Infectious Diseases journal found that people in five states were infected with the virus in December 2019 and early in 2020 before the pandemic truly began last year.
Researchers said that there was evidence of infection in nine out of 24,079 people whose blood samples were taken between Jan. 2, 2020, and March 18, 2020, suggesting “early cases were sporadic.”
The samples that tested positive for the virus came from Illinois, Massachusetts, Mississippi, Pennsylvania, and Wisconsin.
“Antibody testing of blood samples helps us better understand the spread of SARS-CoV-2 in the U.S. in the early days of the US epidemic, when testing was restricted and public health officials could not see that the virus had already spread outside of recognized initial points of entry,” Keri Althoff, the lead author of the study and associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health, said.
“This study also demonstrates the importance of using multiple serology platforms, as recommended by the CDC.”
The study authors noted several limitations to their study. While the study included samples from across the U.S., the number of samples from many states was low. In addition, the authors do not know whether the participants with positive samples became infected during travel or while in their own communities.
Of those samples, at least two showed signs of being infected weeks before public health officials even confirmed that COVID-19 had made its way from Wuhan, China to the US, potentially impacting the country's response to the initial outbreak.
Josh Denny, a co-author of the research, said that “this study allows us to uncover more information about the beginning of the U.S. epidemic.
“Data suggest that more rapid and widespread implementation of testing could have allowed us to better realize the spread might have been worse than initially thought,” researchers noted, “perhaps influencing our level of response.”
Click here to sign up for Daily Voice's free daily emails and news alerts.