According to the study, coronoviruses may have entered the US in early December

According to researchers at UCLA and the University of Washington, new data from medical records in Los Angeles indicate that COVID-19 may still be roaming the United States when China reported the first outbreak of the then-unknown virus to the World Health Organization Was given

In a study published Thursday in the Journal of Medical Internet Research, a team of nine researchers compared electronic medical records to the UCLA health system over the past five years this winter and visited a greater number of outpatient and emergency rooms, of which One complained of “cough” as well as hospitalization for acute respiratory failure at the beginning of the week of January 22, 2019.

From then until the end of February – a 10-week period – he estimated 1,047 more outpatient visits, 514 more emergency department visits and 387 more hospitalizations, suggesting “community dissemination of SARS-CoV-2 Prior to establishing clinical awareness and testing capabilities, ”the researchers wrote.

The first confirmed case of the virus in the US came on January 21, with China calling the WHO “pneumonia of unknown cause” for the first time. This spring it was revealed that the first American death from the virus occurred much earlier than previously known Feb. 6 in Santa Clara County, while other studies have shown that the virus is more widespread in the Bay Area than previously known Was.

However, no diagnostic tests were performed on UCLA patients, so it is unlikely that unchanged cases of COVID-19 are accurately reported to explain the spike in the data.

“Although asymptomatic transmission and community prevalence of COVID-19 have been observed, which are possible explanations for additional patient encounters, other reasons and limitations need to be considered,” the researchers wrote.

For some other reasons, the researchers said, Los Angeles may have an early and particularly strong peak of the 2019 flu season, with the mysterious Vaping disease of 2019 or possibly more people who suffer symptoms like COVID after receiving media coverage in February Seek medical advice. .

According to the Center for Disease Control and Prevention, based on the modeling of previous years’ flu season, based on the flu season of previous years, researchers assumed that it could not be elucidated by flu, while vaping disease occurred less that winter. happened. Researchers said the media was also not a clear explanation because coronoviruses did not begin to receive serious attention in the US until February.

Even compared to the worst flu season of the last five years, researchers found that hundreds of more cases of “cough” occurred in clinics and emergency rooms around the city. In 2016–17, a total of 1,671 patients reported coughing in one outpatient visit, compared to 2,938 in 2019–20, although there are not raw figures for the overall increase in outpatient visits in that time.

Acute respiratory failure, a common symptom of COVID-19, was the worst increase in hospital patients over the past five years, even though overall hospitalizations declined. From December 2018 to February 2019, there were a total of 10,646 hospitals including 996 for acute respiratory failure. In the same period of 2019-20, the number of patients with acute respiratory failure increased to 1,138, while overall hospitalization increased to 9,903.

The researchers wrote, “It is possible that some of these additions represent early COVID-19 disease.”

He set out to identify previously exposed cases of the virus using millions of electronic health records, which he said were underlined in studying epidemiological trends. The UCLA Health System provided him with records of 9.5 million outpatient visits, 575,000 emergency department visits and approximately 250,000 hospital admissions from January 2020 to February 2020.

Researchers used data from the past five years to determine a seasonal average for December through February, then compared this year’s data to see how many additional visits occurred outside the 95% interval of that period .

They looked at 13 weeks of data from the beginning of December to the end of February.

There was no increase in the first three weeks of December, but at the beginning of the week of December 22, the number of outpatient reports of cough symptoms was above that interval for the next 10 weeks. Emergency room visits in six of those 10 weeks were above that interval, while those admitted to hospital were above seven of them.

“A unique feature of this study is the evaluation of three different stages in health care settings,” the researchers wrote. “Data from outpatient clinic settings coming to hospital emergency departments and intensive care units are usually a precursor.”