COVID-19 may have been in Los Angeles as early as last December, study shows

Credit: CC0 Public Domain

In a new study, researchers analyzed electronic health records and found that there was a strong increase in patients with coughs and acute respiratory failure at UCLA Health hospitals and clinics beginning in late December 2019.

This suggests that COVID-19 may have been circulating in the area months before the first definitive cases in the U.S. were identified.

This sudden spike in patients with these symptoms, which continued through February 2020, represents an unexpected 50% increase in such cases when compared with the same time period in each of the previous five years.

The findings demonstrate the importance of analyzing electronic health records to monitor and quickly identify irregular changes in patient populations.

The research was conducted by a team at UCLA.

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.

In the study, the researchers evaluated more than 10 million health system and patient visit records for UCLA Health outpatient, emergency department, and hospital facilities, comparing data from the period between Dec. 1, 2019, and Feb. 29, 2020—the months prior to increased public awareness of COVID-19 in the U.S.—with data from the same period over the previous five years.

They found that outpatient clinic visits by UCLA patients seeking care for coughs increased by over 50% and exceeded the average number of visits for the same complaint over the prior five years by more than 1,000.

Similarly, they discovered a significant excess in the number of patients seen in emergency departments for reports of coughs and of patients hospitalized with acute respiratory failure during this time period.

These excesses remained even after accounting for changes in patient populations and seasonal variation.

The researchers noted that other factors could be responsible for some of this unexpected increase.

For instance, their search for outpatient visit records included only the word “cough” as the reason for clinic visits, which may not have been sufficiently specific, and respiratory illnesses could have been due to vaping, though the use of e-cigarettes had been declining since September 2019.

In addition, they could not rule out that the excess cases were due to the flu.

The team says it is hard to truly know if these excess patients represented early and undetected COVID-19 cases in this area.

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

One author of the study is Dr. Joann Elmore, a professor of medicine.

The study is published in the Journal of Medical Internet Research.

Copyright © 2020 Knowridge Science Report. All rights reserved.