LOS ANGELES, Sept. 10 (Xinhua) -- A new study by American researchers, released on Thursday, suggests the deadly coronavirus may have already reached Los Angeles by late December, actively circulating in the area months before the first definitive cases in the United States were identified.
Researchers at the University of California, Los Angeles (UCLA), evaluated more than 10 million patient and health records for UCLA Health outpatient, emergency department and hospital facilities, spanning Dec. 1, 2019, to Feb. 29, 2020, and compared those records with data from the same period over the previous five years.