Thursday, June 17, 2021, 12:03
Coronavirus was in US in late 2019, study finds
By Ai Heping
In this photo healthcare workers prepare a syringe with a vial of the
J&J/Janssen COVID-19 vaccine at a temporary vaccination site at Grand
Central Terminal train station on May 12, 202 in New York City. (PHOTO / AFP)
A United States government study
published on Tuesday suggests that the coronavirus was infecting people in the
US before causing a deadly outbreak in the Chinese city of Wuhan.
The outbreak hit Wuhan, Hubei
province in late 2019. Officially, the first US infection to be identified was
a Washington state man who returned from Wuhan on Jan 15 that year 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. They analyzed blood samples
from more than 24,000 people across the country. The samples were collected in
the first three months of 2020 as part of a long-term NIH research program
called All of Us that seeks to track 1 million people in the US over the years
to study Spokesman: US should work with WHO in tracing virus, the way China did
their health.
Chinese Foreign Ministry spokesman Zhao Lijian said at the daily news briefing that the study proves once again that tracing the origin of the virus is a complicated scientific issue involving different countries and places
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 of the
participants had mild symptoms. One of those in Illinois was infected as early
as Nov 24, said Keri Althoff, an associate professor at the Johns Hopkins
Bloomberg School of Public Health and the study's lead author.
Chinese Foreign Ministry
spokesman Zhao Lijian said at the daily news briefing on Wednesday that the
study proves once again that tracing the origin of the virus is a complicated
scientific issue involving different countries and places.
He said it should be handled by
collective efforts of global scientists to better prevent potential risks in
the future and to protect the safety and health of people across the world.
According to Zhao, many health
experts and media outlets from various countries have pointed out that the
virus broke out in many places and regions.
The international community
should respect this reality, he added, and research in the next phase of World
Health Organization-led origin tracing should be based on a global vision and
conducted in various places, rather than being limited to a certain region.
"We hope other countries can
act like China to conduct cooperation with the WHO on virus origin-tracing
study with an open, transparent and scientific attitude, so as to make due
contribution to boosting global anti-virus cooperation and saving more lives,"
he said.
The NIH researchers haven't yet
followed up with study participants to see if any had traveled outside the US
before they were infected. But they found that the seven whose samples came
from blood donated before the date of the first diagnosis in their states
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 used multiple
types of tests to minimize false positive results. Some experts said it is
still possible that the 2019 positive samples were infections by other
coronaviruses and not the pandemic strain.
Some experts also said the new
study is flawed because the researchers didn't have travel information for any
of the patients, and such information could 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.
However, 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, Hensley said.
Josh Denny, chief executive of
the All of Us program, told the Times that "it's still very possible that
some of them might be false positives", but that all of them being 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 US 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, the principal
investigator of the CDC's respiratory virus immunology team, told AP:
"There was probably very rare and sporadic cases here earlier than we were
aware of."
Althoff, the study's lead author,
said, "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."
Zhao Jia and Yang Ran in Beijing
contributed to this story.
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