A spike of patients with coughs and acute respiratory failure in December 2019 in Los Angeles suggests COVID-19 may have been circulating months before the first definitive U.S. cases were identified, a new study showed.
The surge in patients with those symptoms at UCLA Health hospitals and clinics continued through February — and had an unexpected 50% increase compared with the same time period in each of the previous five years, UCLA researchers reported.
The study was posted Wednesday in the peer-reviewed Journal of Medical Internet Research.
“For many diseases, data from the outpatient setting can provide an early warning to emergency departments and hospital intensive care units of what is to come,” Dr. Joann Elmore, the study’s lead author and a professor of medicine at the David Geffen School of Medicine at UCLA, said in a statement.
“The majority of COVID-19 studies evaluate hospitalization data, but we also looked at the larger outpatient clinic setting, where most patients turn first for medical care when illness and symptoms arise.”
The researchers evaluated more than 10 million health system and patient visit electronic records for UCLA Health outpatient, emergency department and hospital facilities in their study.
“We may never truly know if these excess patients represented early and undetected COVID-19 cases in our area,” Elmore said. “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.”
The first confirmed U.S. case was recorded in a traveler who returned to the state of Washington from Wuhan, the Chinese city thought to be the epicenter of the pandemic, on Jan. 15.
A month later, on Feb. 26 and Feb. 28, the first cases of community spread were detected, the Centers for Disease Control and Prevention reported.
Beijing said the disease was first recorded in a Wuhan market just before Christmas. But it has been hit by claims the government knew about it earlier.
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