UCLA-led study suggests COVID-19 may have been in LA earlier than previously thought
A UCLA study found a significant rise in patients with respiratory complaints and illnesses during December and January, raising the question of whether COVID-19 was already in Los Angeles before its detection. The study utilized methods that could possibly detect new and changing illnesses to prevent future outbreaks.
(Photo by Kanishka Mehra/Photo editor, Photo illustration by Shruti Iyer/Daily Bruin senior staff)
Oct. 2, 2020 9:13 p.m.
COVID-19 may have been in the Los Angeles area before the first identified cases in the United States, according to a UCLA-led study.
The researchers analyzed electronic health records from more than 2.5 million annual patient visits across three hospitals and 180 clinics in the LA area between July 2014 and February, according to the study published in the Journal of Medical Internet Research.
The study investigated whether there were more visits with the symptom “cough” in the months from December to February compared to the previous five years.
COVID-19 was first reported on Dec. 31 in Wuhan, China, according to the World Health Organization. The first recorded COVID-19 case in the U.S. occurred in Washington in January, while the first recorded case in LA also occurred in January.
Joann Elmore, the lead author of the study and a professor of medicine and health policy and management at UCLA, said there was a 50% increase in patients who showed symptoms of a cough in the months between December and February compared to the last five years. There were also 1,000 more patients treated in winter 2019 for a cough compared to the average amount of patients treated in the previous five years, she added. Coughing and acute respiratory failure are both symptoms of COVID-19, according to the Centers for Disease Control and Prevention.
Elmore, a physician and epidemiologist, said she received calls from patients in March and April asking if their symptoms from a few months earlier were due to COVID-19.
“Early on in this pandemic, everybody was publishing about the intensive care unit, and worrying about the number of ventilators,” Elmore said. “That’s just the tip of the iceberg. … There are a lot of people that get viruses and infectious diseases in the larger community population, and if they aren’t terribly ill, they come to me in the (outpatient) clinic.”
Thomas Payne, a professor of medicine at the University of Washington and a co-author of the study, said the study does not prove that patients had COVID-19 before January but instead raises the question of whether COVID-19 was in Los Angeles earlier than reported.
“In situations like this, that’s sort of the way scientists are supposed to work,” said Kathleen Kerr, a biostatistics professor at the University of Washington and a co-author of the study. “One study can’t be definitive, but an accumulation of evidence can help scientists and policymakers reach a conclusion by combining data from multiple sources and asking the same question from different perspectives.”
Elmore said the researchers studied three separate groups: outpatient clinics, emergency departments and hospitals.
Kerr said the research staff collected the data from UCLA Health’s system after it received permission from UCLA Health’s ethics board to use medical data.
The team began by pulling all of the outpatient records with the word “cough” from the medical record system, Elmore said.
The team noticed there were more cases during the winter in the last five years, as to be expected because of the larger amount of cases of colds or the flu in the winter, Elmore said. However, when compared to previous winters, the cases in the winter of 2019-2020 were significantly higher, she added.
The team used a model to determine if there were more patients who reported symptoms of coughing or respiratory distress, according to the study.
Given the data, the team used the model to predict how many patients would report coughing symptoms between December and January, Kerr said. The model showed that cases began to rise above the prediction starting in late December through January, she added.
The trend was the same for emergency department visits as well as for hospital discharge diagnoses for patients with symptoms of a cough or acute respiratory failure, Elmore said.
“(The method) is novel in that what we did was very simple, so simple that any hospital anywhere in our country could do the same thing,” Payne said. “And maybe we should all be doing it.”
Elmore said the methods were innovative because they allowed the researchers to learn from vast quantities of existing data. Researchers can use artificial intelligence to identify future virus outbreaks sooner, she added.
“You could harness artificial intelligence and machine learning and set up a system that will alert you if your patient population has an unusual change,” she said. “And my hope is that in the future, we will learn how to harness data to help alert us.”