Marin County public health officials have quarantined two senior residential care centers and a preschool because of an outbreak of a flu-like illness.

The suspected culprit is norovirus, a gastrointestinal illness that causes nausea, vomiting, diarrhea and stomach cramps. Most people who are infected recover in two to three days without hospitalization and with no long-term health effects. But deaths have occurred in some cases. The greatest risk is dehydration because of vomiting and diarrhea in the very young and elderly.

So far, 36 people, including patients and staff members, have fallen ill at Aegis Living of San Rafael at 111 Merrydale Road, which has 70 beds, said Shanna Cronan, a nurse speaking on behalf of the Marin County Division of Public Health Services. At Aegis Living in Corte Madera at 5555 Paradise Drive, 37 people have become sick, Cronan said. The quarantine at the San Rafael center might be lifted Tuesday.

Cronan said Public Health Services didn’t learn of the outbreak at the preschool until Monday, even though it began on Jan. 13. So far, 16 children and adults have become ill at the preschool, which she declined to identify.

She said not enough test samples have been collected yet to determine the cause of any of the outbreaks. Norovirus is suspected, however, based on the symptoms being displayed.

The outbreak at the San Rafael facility began Jan. 14, and the first illness at the Corte Madera facility occurred on Thursday, Cronan said. Both are owned by Aegis Senior Communities, a limited liability corporation.

Cronan said Aegis waited until Friday to notify Public Health Services of both outbreaks. She said notification should have occurred sooner because facilities are required to contact the county within 48 hours once they have two or more “cases with acute onset of vomiting or diarrhea, or one lab-confirmed case.”

A Novato resident who has a family member living at Aegis Living of San Rafael said the management there never notified her of the outbreak. The woman, who asked that she not be identified, said she learned of the quarantine only when the family member phoned her.

Mary Crowe, the executive director of Aegis Living of San Rafael, said relatives of the people living at the San Rafael center were notified of the outbreak on Friday.

“We are taking preventative measures, which means we are asking people not to visit. It’s very standard,” Crowe said. “We haven’t had any new cases in 24 hours so I think we’re pretty clear.”

Crowe said the two Aegis facilities do share some employees. “There are a couple that work part-time that go back and forth,” she said. Diane Savard, the administrator of Aegis Living in Corte Madera, was unavailable for comment.

Rebecca Ng, chief of Marin County’s Division of Environmental Health Services, said she first learned of the three new outbreaks when she was contacted by the Independent Journal on Monday. Ng said normally her department is notified immediately when gastrointestinal illnesses occur so the facilities’ kitchens can be inspected for possible sources of contamination. But Marin County’s public health officer, Dr. Jason Eberhart-Phillips, said he personally sent Ng an email on Friday informing her of the outbreaks at the Aegis facilities.

Environmental Health Services was not notified in November when a norovirus outbreak at Country Villa Novato Healthcare Center in Novato resulted in at least 80 residents and staff members becoming ill. Cronan said the norovirus outbreak at Country Villa was one of three at Marin County nursing homes that month; each resulted in a county-mandated quarantine. But Cronan would not identify where the other outbreaks occurred.

Eberhart-Phillips said that if the county were to make public the names of facilities where outbreaks occur, managers there would be less likely to notify the county. Officials, however, have confirmed the sites of local outbreaks when specifically asked about them by the Independent Journal.

Pat McGinnis, executive director of California Advocates for Nursing Home Reform, a statewide nonprofit advocacy organization, said the county’s refusal to identify the locations of all outbreaks “is very unusual. It’s a county public health department. It’s supposed to be public information.”

Contact Richard Halstead via e-mail at