Los Angeles County is currently listed in the U.S. Centers for Disease Control and Prevention's "medium" virus-activity category, based on its cumulative seven-day rate of new cases. But the county will move into the "high" category if its average daily rate of new COVID-related hospital admissions rises above 10 per 100,000 residents, or if the percentage of staffed hospital beds occupied by COVID-positive patients tops 10%.
Public Health Director Barbara Ferrer said the county's current rate of new hospital admissions is now 5.2 per 100,000 residents, double the rate from a month ago. The portion of beds occupied by virus patients is still relatively low at 2.7%, but also higher than it was last month.
"While these hospital metrics remain well below the threshold for 'high' in the CDC's community-level framework, both our weekly case rate and the rate of increase in hospital admissions are of concern,'' Ferrer said. "If we continue on the current trajectory... we're likely to move into the CDC 'high' community level within a few weeks, towards the end of June, indicating an increased stress on the health care system."
If the county reaches the "high" category, it will again require that masks be worn in all indoor public settings.
Ferrer said there is "no certainty" on the date when the county might reach the "high'' level.
"Actual hospital admissions could increase at a faster rate, or if case numbers stabilize or decrease in the next two weeks, the rate of increase in hospitalizations could be a lot lower," she said. "As we look to the near future, it reminds us that we ourselves also have the ability to influence where these numbers go. We all have the power to take steps to reduce the amount of viral spread, which ultimately reduces the number of people that are in the hospital with a positive COVID-19 infection."
She applauded the step taken by Alameda County in Northern California, where an indoor mask mandate will take effect again on Friday. And she pointed to a pair of recent studies that suggested mask-wearing has a notable impact on reducing spread of the virus.
According to one study, which was conducted in California, the odds of testing positive for COVID were 56% lower for people who reported always wearing a mask in indoor public settings, versus those who never wore one.
The odds were 83% lower for people who work higher-grade masks -- such as N95 or KN95, Ferrer said.
The second study, conducted in Arkansas, found that school districts with universal masking requirements had 23% lower case rates.
Los Angeles County currently requires masks indoors at health care facilities, aboard transit vehicles and in transit hubs such as airports, in long-term care facilities, in shelters and cooling centers and in correctional facilities.
The county on Thursday reported 5,047 new COVID infections, raising the county's cumulative total from throughout the pandemic to 2,985,665. Ten new deaths were also reported, lifting the virus-related death toll locally to 32,146.
The average daily rate of people testing positive for the virus rose to 5.3%, an increase Ferrer said is likely a combination of increased community transmission and reduced overall testing due to the end of the school year.
According to state figures, there were 524 COVID-positive patients in county hospitals as of Thursday, up from 502 a day earlier. The number of those patients being treated in intensive care was 59, up from 53 a day earlier.