SANTA ANA, Calif.—Orange County’s latest weekly COVID-19 averages show a sharp increase in cases, largely due to the Delta variant, which has been characterized as a “game changer” by one local expert. According to numbers released July 27, Orange County’s average daily case rate per 100,000 residents increased from 4.9 to 8 in a one-week period, and the test positivity rate jumped from 3.3 to 4.9 percent. The county’s Health Equity Quartile rate, which measures the disadvantaged communities hardest hit by the pandemic, increased from 3.4 percent to 4.4 percent. The positivity rate is more alarming as it reflects more people being infected rather than an increase in testing, said Andrew Noymer, an epidemiologist and University of California–Irvine professor of population health and disease prevention. “Delta is exploding everywhere,” Noymer told City News Service. “It’s become apparent Delta has become a big game changer.” Orange County reported 453 new cases …