A trio of new studies published Thursday seem to push back the start of the covid-19 pandemic in the U.S. Two of the studies suggest that the coronavirus behind covid-19 was spreading locally in Washington State in late January to early February, while another suggests it was sickening people in Los Angeles last December. These estimates are all at least weeks before the first local cases of the viral illness were clearly documented in the U.S.
One study, published in the Journal of Medical Internet Research, looked at the past five years’ worth of electronic health records from a large health care system in the Los Angeles area affiliated with the University of California Los Angeles. These records were combed through for cases where people brought up a cough as one of their medical complaints—a common covid-19 symptom—as well as hospitalizations involving acute respiratory failure. The earlier years, starting in 2014, were used as a baseline to establish how many people sick with these complaints visited UCLA hospitals and outpatient clinics during the typical winter, which was then compared to the 2019-2020 winter.
The researchers found that the number of cases involving cough started to rise above the average level seen in recent years by the week of December 22, 2019—a trend that continued up through February 2020, when the researchers’ analysis stopped. Hospitalizations related to respiratory failure followed the same trend. Overall, they estimated that UCLA clinics and hospitals saw nearly 200 cough-related outpatient cases, 56 emergency room visits, and 18 related hospitalizations more than expected during those months.
While the above numbers may not seem like much, they only account for a single health care system in the area. Moreover, as the authors note, this uptick in complaints could have just been the tip of the iceberg.
“If only some of these excess visits are due to COVID-19, this could still represent community spread of SARS-CoV-2 during that time because a substantial proportion of individuals infected have no symptoms or mild symptoms and do not seek medical care, making cryptic spread of the disease within a community likely,” they wrote (“cryptic” spread just means unnoticed transmission)…Read more>>