A study published in the JMIR medical journal today suggests that COVID-19 may have been present in Los Angeles as early as December last year. The research undertaken by UCLA and the University of Washington investigated electronic health records from UCLA Health to determine the number of outpatient visits that included the word ‘cough’ in winter 2019, compared to the same period in the 5 years prior. Health records from patients hospitalized with acute respiratory failure during that timeframe were also analyzed. The study found that a ‘significantly higher number of patients presented to outpatient clinics and emergency departments in this health system with a complaint of cough starting the last week of December 2019 and continuing through January and February 2020.’ The JMIR paper continues that a ‘significant excess in the number of patients hospitalized with acute respiratory failure during this same time period was also noted.’
A Washington Post article also published today on this topic, notes that “the researchers cautioned that the results cannot prove that the pathogen reached California so soon, and other disease trackers expressed skepticism that the findings signaled an early arrival.” The JMIR paper addresses other limitations in the research also. It reiterates that ‘cough’ was the only word that was searched for, and that the “search method has imperfect specificity and sensitivity as it does not include the full spectrum of COVID-19 symptoms.” It also notes that both a severe influenza season and the possibility of vaping side effects have been considered as reasons for an increase in the number of people complaining of coughs in late 2019. Both of these explanations are stated to be unlikely causes of increased coughing however, due to 5 years of data being investigated, and a decline in vaping in Q4 2019.
Another outcome of the paper is that it provides a roadmap for how to mine electronic health records for data that may help understand and predict future hospitalizations. “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,” the paper reads. “This SARS-CoV-2 pandemic highlights the urgent need to support the development of agile health care analytics that enable real-time symptom and disease surveillance. Lessons learned from this pandemic will hopefully lead to better preparation and the ability to quickly provide warnings and track the next pandemic.”
Google search data was also used in this research, though it pointed to significant increases in searches of the word “cough” in March rather than December of 2019. “Using data from Google Trends, the popularity of “cough” as a search term in the United States was slightly higher from late December 2019 through January 2020 when compared with the average national popularity in the previous 4 years. Popularity of searches for “cough” increased substantially in mid-March, corresponding to the sharp increase in “coronavirus” Google news searches. Although there was almost no mention of a COVID-19–type illness by United States media in December 2019 and little mention in January 2020, substantial media attention was present in February 2020.”
UCLA’s Dr. Joann Elmore, a co-author of the paper, spoke to Yahoo News about the research today. “Many of my colleagues at UCLA were wondering if the patients we had seen a few months earlier, those that had really severe symptoms if they might have had COVID,” Dr. Elmore said. In addition to being a primary care physician with UCLA Health specializing in internal medicine, Dr. Elmore is a professor in the Department of Medicine at the David Geffen School of Medicine at UCLA and health policy and management at the UCLA Fielding School of Public Health. “My patients started emailing me with the same questions,” Dr. Elmore told Yahoo News, further prompting her to research electronic medical records to investigate whether there was an increase in complaints of coughs in 2019 compared to other years.