A New US Government Study Published Tuesday Suggests That The Coronavirus Was Infecting Americans Before It Was Causing A Deadly Outbreak.
A New US Government Study Published Tuesday Suggests That The Coronavirus Was Infecting Americans Before It Was Causing A Deadly Outbreak In Wuhan, China. The virus emerged in Wuhan in late 2019. Officially, the first US infection to be identified was a traveler — a Washington state man who returned from Wuhan on Jan 15 and sought help at a clinic on Jan 19.
The study’s results suggest that the virus may have been circulating in Illinois, for example, as early as Dec 24, 2019, although the first case in that state was confirmed a month later. The study was published online by the journal Clinical Infectious Diseases and was conducted by a team including researchers at the National Institutes of Health (NIH). They analyzed blood samples from more than 24,000 people across the country, collected in the first three months of 2020 as part of a long-term study called “All of Us” that seeks to track 1 million Americans over years to study their health.
The researchers found evidence of infection in just nine out of 24,079 participants whose blood samples were taken between Jan 2, 2020, and March 18, 2020, for the NIH research program. Seven of the samples came from blood donated before the date of the first diagnosis in their states — Illinois, Wisconsin, Pennsylvania, Mississippi and Massachusetts. At least a couple had mild symptoms. One of the people in Illinois was infected as early as Christmas Eve, said Keri Althoff, an associate professor at the Johns Hopkins Bloomberg School of Public Health and the study’s lead author.
The NIH researchers haven’t followed up with study participants yet to see if any had traveled out of the US prior to their infection. But they found that the seven didn’t live in or near New York City or Seattle, where the first wave of US cases were concentrated. Researchers at the NIH and studies by the US Centers for Disease Control and Prevention (CDC) used multiple types of tests to minimize false positive results, but some experts say it still is possible their 2019 positives were infections by other coronaviruses and not the pandemic strain.
Some experts also said the latest study is flawed because the researchers also didn’t have travel information for any of the patients, which might have helped explain the test results. “This is an interesting paper because it raises the idea that everyone thinks is true, that there were infections that were going undiagnosed,” Scott Hensley, an immunologist at the University of Pennsylvania, told The New York Times.
But the small number of samples that tested positive made it difficult to be sure that they were true cases of infection and not just a methodological error, he said. “It’s hard to know what is a real signal and what isn’t,” Hensley said. “It’s still very possible that some of them might be false positives,” Dr Josh Denny, chief executive of All of Us, told the Times. But “the fact that all of them would be false positives seems pretty unlikely with what we’ve done”.
William Hanage, a Harvard University expert on disease dynamics, told The Associated Press, “While it is entirely plausible that the virus was introduced into the United States much earlier than is usually appreciated, it does not mean that this is necessarily strong enough evidence to change how we’re thinking about this.”
Late last year, researchers at the CDC and the American Red Cross reported that there could have been isolated cases of COVID-19 in the US as early as mid-December 2019. The researchers said they found evidence of infection in a young man who gave blood in Northern California at that time, and in an individual who donated in Connecticut on Jan 10, 2020.
Another study published in the scientific journal Nature Communications earlier this month found evidence of sporadic coronavirus cases in New York City a month before the first officially documented case and the city’s pandemic wave in March 2020. Natalie Thornburg of the CDC said, “There was probably very rare and sporadic cases here earlier than we were aware of. But it was not widespread and didn’t become widespread until late February.” She is the principal investigator of the CDC’s respiratory virus immunology team.
“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,” said Althoff. The cases the researchers found, she said, suggest the new virus was “being seeded perhaps in states that we didn’t necessarily have on our radar before this”.
This news was originally published at China Daily.