As coronavirus cases in Marin continue to rise, health officials are focusing containment efforts on senior centers, which account for 80% of the county’s COVID-19 deaths.

A team of health care workers is testing the residents and staff on a weekly basis at the centers in Marin with confirmed cases, officials said.

Since the beginning of the pandemic, that team has “stewarded at least eight outbreaks to completion,” said Dr. David Miller, an infectious disease specialist at Kaiser hospital in San Rafael, who is one of the leaders of the effort to control the spread of the coronavirus in Marin’s senior homes.

There are 55 residential care facilities and 13 skilled nursing centers in Marin with a combined 2,700 residents, according to Miller. Health care workers are actively testing the residents and staff at 33 of those facilities that are experiencing outbreaks or at risk of seeing outbreaks develop, Miller said Friday during a virtual town hall.

“This is a virus where you can have few symptoms or no symptoms at all, so we do these mass testing events where we test all the staff and all the residents,” he said. “And we do that repeatedly, every seven days.”

In total, 118 Marin County senior home residents have contracted the virus, and 63 of those cases are active, according to county data. Additionally, 146 staff members at those facilities have tested positive for the virus, and 43 of those cases are active.

Senior homes account for roughly 10% of Marin’s coronavirus cases, but a much higher proportion of the county’s COVID-19 deaths. Of the 29 Marin residents who have died with coronavirus, 23 of them were residents at residential care facilities or nursing centers, Miller said.

One of the county’s worst outbreaks has hit Marin Post Acute, a 170-bed nursing home on North San Pedro Road in San Rafael. Eighty-six people have contracted the virus there, including 66 residents and 20 staff. At least five residents have died, according to the facility’s administrator, Ethan Flake.

Marin’s public health officer, Dr. Matt Willis, said every coronavirus outbreak at a seniors’ home has started with a staff member who contracted the virus and spread it to the residents. He said the only way to protect the population that lives in those homes is to prevent virus transmission throughout the county. But cases continue to rise.

“We’ve seen a significant increase in our cases statewide, regionally, in Marin and nationally,” Willis said. “COVID-19 is surging.”

As a result, Gov. Gavin Newson has ordered renewed restrictions on California businesses, including the closure of indoor dining rooms, bars, movie theaters, zoos and museums throughout the state. For counties on the state’s “watch list” for troubling coronavirus trends, including Marin, Newsom also ordered hair salons, nail salons, gyms, churches and non-essential offices to close indoor operations.

Willis said people have grown impatient with stay-at-home restrictions, but he urged Marin residents to be cautious about being “too causal and too relaxed in our behavior.”

“The virus is teaching us that we don’t really have the luxury of doing those things yet, and we need to move back much closer to the way we’ve been living when we were so successful in the earlier chapter of the shelter-in-place in March,” he said.