LOS ANGELES—Los Angeles County set another daily record with 45,584 positive COVID-19 tests on Jan. 9, continuing a winter surge in transmission driven by the Omicron variant of the coronavirus. On Friday, health officials reported a then-record 43,712 new infections, and on Saturday they said the county had seen more than 200,000 confirmed COVID-19 cases over the past 7 days, the highest number in one week since the beginning of the pandemic. The record numbers seem driven in part by increased testing. The county’s rolling average daily rate of people testing positive for the virus was 20.6 percent, up from 20.4 percent on Saturday, but down from 22.7 percent last Monday. Overall, 10,317,000 individuals have been tested, with 18 percent of people testing positive to date, according to the Los Angeles County Department of Public Health. The department also reported an additional 13 deaths associated with the virus Sunday, bringing …