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Think you’ve already had it? Study reveals COVID-19 was likely in Seattle as early as Christmas

SEATTLE — By the time news spread to the U.S. about the COVID-19 outbreak happening in Wuhan, China, in January, the coronavirus was already being spread around Seattle, according to a study by the University of Texas at Austin, which suggests the virus was likely in Seattle around Christmas.

Dr. Lauren Ancel Meyers — an author of the study published in medical journal The Lancet — examined data for throat swabs taken in Seattle and Wuhan during the flu outbreak, and calculated that for every seven people in the Seattle area who had undiagnosed flu symptoms, one of them likely had COVID-19.

"This virus was spreading before we really were aware of it, and not just in Seattle, it was probably in many cities." Ancel Meyers said. "A lot of people say 'Well, I remember being sick back in December or back in January, and maybe I had COVID.'"

On March 9, a week before schools in Seattle were ordered closed, there were 245 reported cases of the virus. The study indicates at least 9,000 people with flu-like symptoms actually had COVID-19 — and that about a third of that total were children.

"The takeaway for people in Seattle and everywhere else is that this virus, particularly when we're not doing a lot of testing, can spread silently for a while before we know we have an issue on our hands," Ancel Meyers said.

The study also suggests that by the time Gov. Jay Inslee knew to react and order the closure of schools and businesses, the virus had a head start.

"If they had waited a little bit longer it might have been too late," Ancel Meyers said. "It might've been even harder to slow the spread before hospitalizations got to really unmanageable proportions."

The study compared Wuhan, China to Seattle, and found both cities didn't realize there was a major problem, until many thousands of people were infected.

“Given that COVID-19 appears to be overwhelmingly mild in children, our high estimate for symptomatic pediatric cases in Seattle suggests that there may have been thousands more mild cases at the time,” wrote Zhanwei Du, a researcher in Ancel Meyers’ lab and lead author on the study, according to a University of Texas publication.

According to several other studies, about half of COVID-19 cases are without symptoms, leading researchers to believe that there may have been thousands more infected people in Wuhan and Seattle before each city’s respective lockdown measures went into effect.

“This virus is stealthy,” she said, adding, “It spreads very quickly. It often spreads silently. We can have many people infected before we even know that we have an outbreak on our hands.”