(Reuters) – Two residents at a long-care facility in British Columbia with no recent travel history have tested positive for the new coronavirus infection, making it Canada’s first known case of the disease at a nursing home, provincial officials said on Saturday.

The two residents at Lynn Valley Care Centre in North Vancouver tested positive after a health worker at the facility was detected with the coronavirus, prompting authorities to conduct extended tests, British Columbia health officer Bonnie Henry told reporters.

“This is one of the scenarios.. we have been most concerned about,” Henry said. “We know that the risk for elderly people, having this disease, is very concerning and they are likely to have more severe disease. Particularly older people with underlying chronic illness.”

An outbreak protocol is curtailing movement of people in and out of Lynn Valley as authorities conduct a detailed investigation to detect other potential cases there and people who could have been exposed to the healthcare worker, Henry said.

Virus outbreaks are especially problematic in nursing homes because residents live in close quarters, so infections can spread easily. Older residents also tend to have weaker immune systems and underlying health conditions, making illnesses easier to catch and more dangerous if contracted.

In the United States, an outbreak of the coronavirus at a long-term care facility in Kirkland, Washington, has resulted in at least six deaths.

Lynn Valley has over 200 residents, British Columbia’s health minister, Adrian Dix, said.

British Columbia announced another four new coronavirus cases on Saturday, taking total cases in Canada to 51.

On Thursday, the province said it had what could be Canada’s first case of community spread of the virus, when a woman with no recent travel history was tested positive.

(Reporting by Denny Thomas; Editing by Leslie Adler)