COVID-19 May Have Been In LA In December, Say UCLA Researchers

LOS ANGELES, CA — UCLA researchers and colleagues have found that there was a significant increase in patients with coughs and acute respiratory failure at UCLA Health hospitals and clinics beginning in late December, suggesting that COVID-19 may have been circulating in the area months before the first definitive cases in the U.S. were identified in mid-January.

This sudden spike in patients with these symptoms, which lasted from the week of Dec. 22 continued through February, represents an unexpected 50% increase in such cases when compared with the same time period in each of the previous five years. Through analyzing records of emergency room visits and hospital records going back more than five years, researchers from the Journal of Medical Internet Research found 2,938 patients going to a clinic seeking help for a cough between Dec. 1, 2019 and Feb. 29, 2020. That is about 1,047 more than the average number of cough patients seen during the same three-month period in the previous five years.

Researchers also found 1,708 cough patients in December, January, and February, 514 more than the average for the previous five winters, and 1,138 patients were hospitalized during those months for acute respiratory failure, or 387 more than the average of the five previous winters.

Some of these visits may have just been the flu, but there are signs that it might have been COVID-19. In mid-March, seven patients treated at Los Angeles County-USC Medical Center in mid-March for flu-like illnesses actually had COVID-19, and the fact that they had no clear ties to anyone who had recently visited a COVID-19 hotspot means they could’ve been infected through community transmission.

The authors of the study say that the findings demonstrate the importance of analyzing electronic health records to monitor and quickly identify irregular changes in patient populations. The researchers' approach, in which they focused not only on hospitalization data but also on data from outpatient settings, may help epidemiologists and health systems detect future epidemics sooner.

"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," said Dr. Joann Elmore, the study's lead author and a professor of medicine in the division of general internal medicine and health services research at the David Geffen School of Medicine at UCLA. "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."

As scientists and doctors continue to learn more about SARS-CoV-2, the virus that causes COVID-19, health systems and public health agencies are also attempting to predict and monitor cases. Analyzing electronic patient records, the researchers say, could help health authorities more effectively identify and control outbreaks like the current pandemic, which has killed hundreds of thousands worldwide and disrupted billions of lives.

"The pandemic has really highlighted our need for agile health care analytics that enable real-time symptom and disease surveillance using electronic health records data," said Dr. Michael Pfeffer, a study co-author and chief information officer for UCLA Health. "Technology, including artificial intelligence powered by machine learning, has further potential to identify and track irregular changes in health data, including significant excesses of patients with specific disease-type presentations in the weeks or months prior to an outbreak."

— City News Service and Patch staffer Michael Wittner contributed to this report.