LOS ANGELES (CNS) — The number of COVID-positive patients in Los Angeles County hospitals has increased by 30 people to 540, according to the latest state figures out Sunday.

Of those patients, 63 were being treated in intensive care, up from 61 on Saturday.

The overall total had dipped as low as 209 in late April.

County Public Health Director Barbara Ferrer noted last week that while the majority of virus-positive patients were actually admitted to hospitals for reasons other than COVID — and many were unaware they were infected until they were tested upon admission — the patients still put added strain on the health care system, requiring extra infection-control measures in hospitals that standard patients do not.

Ferrer also said that if the quickening pace of virus-related hospital admissions seen over the past few weeks continues, the county could be moved to the U.S. Centers for Disease Control and Prevention's "high" virus-activity category by the end of the month. Reaching that category would mean a return of mandatory indoor mask wearing rules.

The county will move from the "medium" category 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%.

As of Thursday, the county's rate of new hospital admissions was 5.2 per 100,000 residents, double the rate from a month ago. The portion of beds occupied by virus patients was still relatively low at 2.7%, but also higher than it was last month.

"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," Ferrer said Thursday.

On Friday, the county reported 5,051 new COVID infections, raising its cumulative total from throughout the pandemic to 2,990,651. Another 10 deaths were also reported, giving the county an overall virus-related death toll of 32,154.

The average daily rate of people testing positive for the virus was 5% as of Friday.

The county does not report COVID data on weekends.

While indoor masking remains optional in most public locations for now, Ferrer urged people to consider masking up to limit spread and protect vulnerable populations.

"Each resident should consider not only their own personal risk, but also the risk to family members, friends, co-workers and those sharing public spaces, as they make decisions about taking precautions such as masking, gathering, getting tested, and getting vaccinated or boosted," she said in a statement Friday.

"In situations where transmission risk is higher, we know with certainty that masking allows us to protect ourselves and those around us. Masking helps protect those in our county who are more vulnerable. We help keep everyone working. And it is a fairly simple way to do our part to help prevent overburdening the health care system we all depend on."

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.