Virus may have reached US shores before China announced outbreak

WAS the novel coronavirus on the loose in Los Angeles in December, before the World Health Organization was even aware of an unusual cluster of pneumonia cases in Wuhan, China?

A new analysis of records from the University of California (UCLA), Los Angeles’ hospitals and clinics suggests the answer might be yes.

Researchers from UCLA and their colleagues at the University of Washington

documented an unmistakable uptick in patients seeking treatment for coughs. The increase began the week of December 22, 2019, and persisted through the end of February.

Officials with the US Centers for Disease Control and Prevention first recognised that the virus had reached American shores in mid-January, when a man in Washington state who had travelled to the area around Wuhan tested positive for an infection. By then, UCLA doctors may have treated dozens of Covid-19 patients without realising it, the study authors wrote. (It would take another three weeks for Covid-19 to get its official name.)

“A significantly higher number of patients with respiratory complaints and diseases starting in late December 2019 and continuing through February 2020 suggests community spread of Sars-CoV-2 prior to established clinical awareness and testing capabilities,” wrote the team led by Dr Joann Elmore, who is an internist and professor of health policy and management at UCLA.

To look for signs of early Covid-19 patients, Elmore and her colleagues searched through more than 9.5 million outpatient visits, nearly 575 000 emergency room visits and almost 250 000 hospital admissions going back more than five years.

The search of medical records turned up 1 138 patients who were hospitalised in December, January or February and treated for acute respiratory failure. “It is possible that some of this excess represents early Covid-19 disease before clinical recognition and testing,” Elmore and her colleagues wrote.