LOS ANGELES (CNS) — With the omicron variant fueling COVID-19 spread across the county, the number of school campuses reporting positive cases rose sharply as classes resumed this month, but the rate of students and staff testing positive for the virus has begun declining, health officials said Wednesday.

According to the county Department of Public Health, 1,032 K-12 schools reported positive cases last week, a 55% increase from the first week of December, when 665 campuses confirmed infections.

Health officials noted that while roughly 65,000 students and staff tested positive last week, only three new school outbreaks — defined as three or more linked cases — were identified. The low number of campus outbreaks indicates that the high number of infections are due to general virus spread in the community, rather than a targeted cluster of cases at schools, according to the county.

County health officials said the rate of students and staff testing positive for the virus was 11% last week, down from 15% the previous week.

"Keeping our schools available for in-person learning during this omicron fueled surge is not easy and I commend our school communities for all the work they are doing to keep children and staff safe," county Public Health Director Barbara Ferrer said in a statement. "This is particularly challenging in our elementary schools where, on average, three-quarters of students are not fully vaccinated, making it critically important to use infection control practices to limit spread of a highly infectious variant.

"Prioritizing and ensuring safety at schools during a surge is only possible if all those at the school commit to complying fully with public health measures," she said. "This cannot be accomplished by administrators or staff alone. Wearing a high-grade face mask both indoors and outdoors when around others is absolutely essential, as all evidence points to the effectiveness of well-fitting high-quality masks in limiting spread of virus particles."

She urged parents to ensure their children are participating in school COVID-testing programs, and to follow quarantine and isolation rules.

Meanwhile, the number of COVID-positive patients in county hospitals continued rising Wednesday, with state figures putting the total at 4,799, up from 4,701 on Tuesday. The number of those patients being treated in intensive care rose to 700, up from 680 a day earlier.

With increased hospitalizations, higher death totals always follow, and the county reported 59 new virus-related fatalities Wednesday. That brought the county's overall virus death toll to 28,181.

Another 31,018 infections were also confirmed, giving the county a cumulative pandemic total of 2,343,821.

While the overall COVID hospitalization number remains below last winter's peak of more than 8,000, health officials stressed that the rising patient population is creating strain at hospitals that were already coping with staffing shortages. Those shortages have been exacerbated by COVID cases among health-care workers, which have also been rising.

The average daily rate of people testing positive for the virus rose slightly Wednesday, to 16.9%, up from 16.3% on Tuesday. The rate had fallen each day since last week, when it topped 20%.

A month ago, the testing-positivity rate was just 2%.