COVID-19 silently arrived in US near Christmas — earlier than thought, UCLA study says

In December, all eyes were on China as it struggled to control the coronavirus, which was seemingly contained within its own borders, a crisis a world away. But a new study finds the deadly virus may have already reached the U.S. by then, and was actively spreading, weeks before the first COVID-19 case was confirmed on American soil.

Researchers with the University of California Los Angeles looked at over 10 million patient and health records spanning Dec. 1, 2019, to Feb. 29, 2020, and records from the previous five years, and found a troubling trend.

Patient visits to UCLA hospitals for coughs spiked 50% compared to years past, surpassing the average number of visits for that specific issue by 1,000, according to the study.

They also noted a “significant” increase in patients admitted for emergency treatment due to coughs, and patients hospitalized for acute respiratory failure.

Researchers argue the unusually high number of visitors, patients and hospitalizations may indicate that the coronavirus had silently arrived and begun establishing a foothold undetected on the West Coast around Christmas 2019.

If true, that would shake up the current narrative of the virus’ origins in the country.

The first U.S. coronavirus case wasn’t confirmed until Jan. 20, in a man who had just returned to Washington from a visit to Wuhan, China. And it wasn’t until a month later, on Feb. 26 and 28, that the first cases of community spread infection were detected, according to the Centers for Disease Control and Prevention.

UCLA researchers can’t say for certain that coronavirus was behind the trends laid out in their study, as it’s impossible to rule out other potential factors, like e-cigarette use, or the flu. Additionally, searching patient visit records by the key term “cough” might not be specific enough, according to the study.

“We may never truly know if these excess patients represented early and undetected COVID-19 cases in our area,” Dr. Joann Elmore said, adding that the team’s research strategy could be used to detect future outbreaks, not just ongoing pandemics.

“But the lessons learned from this pandemic, paired with health care analytics that enable real-time surveillance of disease and symptoms, can potentially help us identify and track emerging outbreaks and future epidemics.”

This story was originally published September 10, 2020 at 4:02 PM with the headline "COVID-19 silently arrived in US near Christmas — earlier than thought, UCLA study says."