UC San Diego Health became the first primary local medical provider to reinstate masking requirements for employees when the county added free coronavirus testing on July 11. The county was responding to a summer COVID-19 surge that started building steam in June.

Updates to local tracking information arrived July 6, with the amount of the virus detected in local wastewater and the percentage of positive tests performed by healthcare organizations on the rise. According to the county’s update, 15.3 percent of test results reported on July 6 were positive, nearly double the 8.1 percent positive reported on June 8.

Local results mirror a nationwide uptick, which the U.S. Centers for Disease Control and Prevention says has pushed the nationwide test positivity rate to 9 percent. Two new variants, KP.2 and KP.3, are driving more infectious coronavirus variants, which made up more than 60 percent of virus detected in San Diego County in the most recent analysis published by SEARCH, a coalition of local research labs.

Dr. Erik Berg, interim medical director of the county’s epidemiology and immunization branch, said the trend is similar to previous summers as new virus variants circulate among a vacationing population.

“We’re not seeing any indications that this is putting a strain on health care resources or that we’re seeing a dramatic increase in mortality,” Berg said. “The main message is: If you’re at high risk for severe disease, get vaccinated and, if you’re experiencing respiratory symptoms or a fever, stay home from work to avoid exposing others.”

COVID risk increases with age and with the presence of certain medical conditions such as heart disease, diabetes, chronic lung disease, obesity, and chronic kidney disease. Pregnant women, those who have recently given birth, and anyone such as organ transplant recipients taking immune system-suppressing drugs are also at a higher risk of severe symptoms, according to the CDC.

UC San Diego Health, looking at its numbers, took additional action, moving up a tier in its existing COVID response plan and reinstating requirements for its employees, whether they work in one of its three hospitals or in an outpatient setting, to start wearing masks when working face-to-face with patients. Masks are not required for non-hospital employees nor for workers not delivering care. The change will be in effect for two weeks, at which point a decision will be made, based on several different measures of viral activity, about whether to increase or decrease infection-prevention measures.

Dr. Christopher Longhurst, medical director at UC San Diego Health, said Thursday that infection and hospitalization trends drove the decision to bring masks back partway. On Thursday morning, he said, university hospitals collectively held 30 patients with coronavirus infections compared to about ten last week.

“In the last week of May, we averaged 15 employees per day off for COVID; by the first week of June, we were up to 20; by the fourth week of June, we were up to 45, and we’re currently tracking 70,” Longhurst said.

While the total number of employees and patients affected remains tiny as a percentage of the overall employee and patient count, especially when compared to the peaks seen during the pandemic, the recent rate of increase warranted action according to the health system’s pre-agreed-upon response plan.

Overall, the executive said, connecting increases in COVID precautions to observed infection trends helps maintain a proportional response.

“We believe it’s the right thing to do both for our employee safety and our patient safety, and that’s why we have this tiered system where we can ramp up and ramp down based on what’s going on,” Longhurst said.

UCSD Health appears to be the first among the region’s large medical providers to mandate masking this year. Scripps Health continues to “highly recommend” masking when its workers are within 6 feet of another person in a clinical area or crowded elevators. Employees wear masks if patients request they cover up.

However, Scripps, Sharp HealthCare, and Kaiser Permanente San Diego all said that their assessments of recent coronavirus trends were not at the threshold requiring masking.

The county also announced expanding no-cost testing availability at its three main public health centers.