(CN) — New research suggests that Covid-19 may have been circulating in the Los Angeles area as early as last December — months before a spike in officially confirmed U.S. cases began to signal the beginning of a pandemic.
Health officials from China and the World Health Organization began to warn of a mysterious strain of pneumonia afflicting dozens in Wuhan, China, in December 2019, reports that would later be identified as the beginning of the novel coronavirus SARS-CoV-2 — which causes the Covid-19 disease — but the official timeline for the virus in the United States would take longer to develop.
While a Washington man became officially diagnosed with the coronavirus in late January after returning from a trip to Wuhan, it would take until February for the first case of suspected local transmission of Covid-19 to be confirmed in the U.S.
By March, the Covid-19 pandemic began ransacking the nation in earnest, with New York surpassing Seattle as the official U.S. outbreak epicenter. States initiated stay-at-home protocols after the U.S. Centers for Disease Control and Prevention began to warn against large social gatherings.
Though this timeline of the coronavirus in the United States has been widely accepted, a new study published Thursday in the Journal of Medical Internet Research suggests the virus may have already been extremely active among LA communities well before the official record would suggest.
To uncover these findings, researchers led by Dr. Joann Elmore, professor at UCLA’s David Geffen School of Medicine, examined extensive outpatient medical data from UCLA Health hospitals and clinics beginning in late December 2019.
Elmore said that while other Covid-19 studies have also looked at similar hospital data, the team behind Thursday’s study looked into a broader range of clinical data from UCLA facilities.
“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,” Elmore said with the release of the study. “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.”
During this process, researchers took a hard look at over 10 million health system and patient visit records for UCLA Health outpatient, emergency department and hospital facilities from December 2019 to February 2020 — months before the sweeping emergency health declarations that began in March.
Researchers then compared this data to comparable information from the same monthly periods going back the last five years to see how these winter months stacked up to previous years.
What they found was that the rate of patients seeking treatment for coughs or other respiratory issues at UCLA facilities increased by 50%.
On top of this drastically increased volume of coughing patients, researchers also observed a significant increase in patients being hospitalized for acute respiratory failure during the same time.
Researchers say these increases that could not be properly explained by changes in patient populations or seasonal factors.
Given our knowledge of Covid-19 and its impact on the human respiratory system, researchers say that the deadly virus responsible for over 190,000 deaths in the United States to date could also have been behind these patient increases.
Researchers warn, however, that these results are not definitive, as there could be a host of other factors that could at least partially explain the surge. Scientists say that the flu, term methodology used to analyze the data or even complications from e-cigarettes and vaping could potentially explain some or all of these figures.
Elmore notes that with all of these variables in place, the earliest days of the Covid-19 pandemic and the presence of early, unconfirmed cases may never be fully understood — but that the lessons we’ve learned this past year could prove invaluable for health experts looking to track future pandemics moving forward.
“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.”