Many 'Flu' Cases in Seattle This Winter Were Actually Covid-19, Study Finds

[Nevilledog]

https://gizmodo.com/many-flu-cases-in-seattle-this-winter-were-actually-cov-1844715129

The start of the covid-19 pandemic in the U.S. may have been earlier and far larger than official records indicate, according to a new study. Researchers found that a substantial portion of people, including children, in Seattle who were suspected of having the flu this past winter likely had covid-19 instead. It also estimates the city may have had thousands of cases by early March, when barely over a hundred cases in the state were reported.

Researchers at the University of Texas at Austin looked back to two different periods during the earliest days of the pandemic: the month of January in Wuhan, China, and the weeks of late February and early March in Seattle, Washington. They studied data from hospitals and doctors’ offices that had collected throat swab samples from outpatients diagnosed with flu-like symptoms; these samples were later reanalyzed for the presence of the coronavirus that causes covid-19.

In both cities, most of these cases turned out to be flu, but over a third were actually covid-19 in Wuhan, while more than one in every 10 cases were covid-19 in Seattle, the team concluded. Based on the known trajectory of the flu season in both areas, the researchers then created a model of how early and widespread covid-19 had likely been during these first weeks.

By their estimates, Seattle already had at least 9,000 cases by March 9, when the city implemented lockdown measures such as closing schools and there were fewer than 200 cases reported in the state as a whole; of these, thousands likely involved children. Wuhan similarly had over 12,000 cases by January 22, right as the Chinese government issued its lockdown and had only a little over 400 official cases. They also estimated that people were spreading the virus in Seattle by the first week of January and possibly even as early as Christmas, while the first Wuhan case emerged sometime between late October to early December.


Study by Lancet

Using the COVID-19 to influenza ratio to estimate early pandemic spread in Wuhan, China and Seattle, US

https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(20)30223-6/fulltext

Abstract

Background

Pandemic SARS-CoV-2 was first reported in Wuhan, China on December 31, 2019. Twenty-one days later, the US identified its first case––a man who had traveled from Wuhan to the state of Washington. Recent studies in the Wuhan and Seattle metropolitan areas retrospectively tested samples taken from patients with COVID-like symptoms. In the Wuhan study, there were 4 SARS-CoV-2 positives and 7 influenza positives out of 26 adults outpatients who sought care for influenza-like-illness at two central hospitals prior to January 12, 2020. The Seattle study reported 25 SARS-CoV-2 positives and 442 influenza positives out of 2353 children and adults who reported acute respiratory illness prior to March 9, 2020. Here, we use these findings to extrapolate the early prevalence of symptomatic COVID-19 in Wuhan and Seattle.

Methods

For each city, we estimate the ratio of COVID-19 to influenza infections from the retrospective testing data and estimate the age-specific prevalence of influenza from surveillance reports during the same time period. Combining these, we approximate the total number of symptomatic COVID-19 infections.

In Wuhan, there were an estimated 1386 [95% CrI: 420-3793] symptomatic cases over 30 of COVID-19 between December 30, 2019 and January 12, 2020. In Seattle, we estimate that 2268 [95% CrI: 498, 6069] children under 18 and 4367 [95% CrI: 2776, 6526] adults were symptomatically infected between February 24 and March 9, 2020. We also find that the initial pandemic wave in Wuhan likely originated with a single infected case who developed symptoms sometime between October 26 and December 13, 2019; in Seattle, the seeding likely occurred between December 25, 2019 and January 15, 2020.

Interpretation

The spread of COVID-19 in Wuhan and Seattle was far more extensive than initially reported. The virus likely spread for months in Wuhan before the lockdown. 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.

*snip*

[SheltieLover]

1. There's a shock.

Someone should look at " flul" deaths in Arkansas!

[tblue37]

2. K&R for visibility. nt

[Blues Heron]

3. what about the Covid+ frozen sewage sample from Barcelona from March 2019?

Anything more on that? That was a weird report from a few weeks back.

[Ms. Toad]

4. I was exposed to it in January, in Ohio - so yes.

A coworker and her family were all ill with it. One diagnosed with walking pneumonia, one with a sinus infection, and the child with the typical lesions (but no specific diagnosis). More recently, a lung X-ray showed the classic damage, and an antibody test confirmed it.

I was in at least 2 meetings, more than an hour duration, less than 6-feet away with the coworker.

So - yes - there was community spread as far back as January (It likely came from Florida to Ohio)