California sees fastest growth in new daily coronavirus cases

People line up for coronavirus tests at a site in Los Angeles on Tuesday.

(CNN)California, which this week announced its 1 millionth Covid-19 case, is seeing the fastest rate of increase in the number of daily reported infections since the start of the pandemic, public health officials said Friday.

There has been a 47.1% increase in the number of new cases in a one-week period since the beginning of this month, according to Dr. Erica Pan, who is currently serving as the state's acting public health officer.
"This is almost a 20% faster rate of rise and the fastest rate of rise we have seen in California," Pan said. "When cases are increasing at this pace, it is really important for us to act quickly."
    The state reported 6,893 additional cases of Covid-19 on Friday, a higher number of new infections than the state's seven-day average of 6,773 cases. The two-week test positivity rate has also increased from 3% to 4%, according to Pan.
    A statewide travel advisory was implemented Friday along with Oregon and Washington, asking residents to refrain from any non-essential travel.
    "Cases are on the rise here in California and we are concerned," California Health and Human Services Secretary Dr. Mark Ghaly said. "As I say to my patients often, 'When I'm worried, I'll tell you so you can worry with me,' and we're there."
    Ghaly expressed his concerns over the increase of cases leading to hospitalizations.
    "About two weeks after a set of cases is reported, we see about 12% of those cases end up in the hospital," he said.
    Hospitalizations in the state have increased more than 30% in the past two weeks.
    "This isn't the time to put our guard down," Ghaly said.
    While he said there are no immediate plans for another statewide stay-at-home order, he suggested that there may be additional restrictions placed on some counties in the future.
    California, home to 40 million residents, became the second state to surpass 1 million Covid-19 infections. Texas, with 29 million people, hit the grim milestone earlier this week.

    'We have to keep a close watch'

    Officials also announced this week three more counties are moving back to the state's most restrictive tier -- indicating widespread Covid-19 risk -- Sacramento, San Diego and Stanislaus counties.
    The tier system is the framework California has set up that helps health officials determine which counties should tighten or loosen restrictions based on certain criteria, including test positivity, adjusted case rate and health equity metric.
    Eight other counties also moved back a tier, indicating substantial or moderate risk in their area.