Canada's Maritime provinces have been hit with a streak of mumps cases, and officials say the infection may continue spreading.
The disease is not fatal, but it can cause severe swelling, pain, and even reproductive problems in men.
Health officials in Cape Breton, N.S. say the province has three confirmed cases, all of them linked to an institute for cancer patients. More than 150 people may have had contact with the virus, and will receive letters notifying them of the risk.
"We will have the precautions in place until later this month," Lynn Gilbert, of the Cape Breton District Health Authority, told CTV Atlantic.
"If there are no new cases, we will be lifting those precautions."
Another 34 people have contracted the mumps in the Halifax-area. Nova Scotia usually has just a few cases each year.
Meanwhile, New Brunswick health officials now confirm 13 cases. It's the first time anyone in the province has been infected with the virus in eight years.
Dr. Scott Giffin, the acting N.B. chief medical officer, suggested a lively bar scene may have contributed to the outbreak. The virus spreads through droplets.
"It does appear that a number of cases may have been transmitted in entertainment areas, where you have loud music," he said.
"When you have loud music, in order to communicate with someone you have to get very close to them and then you essentially yell. That's a good way to transmit the secretions."
Giffin added that the outbreak in Halifax can likely be traced back to New Brunswick.
"It looks like the infections in Halifax may have originated with a case from New Brunswick that actually travelled to Halifax in early February," he said.
Some patients infected with the mumps show no initial symptoms, meaning they can pass on the virus without knowing.
"You could be contagious for up to a week before the symptoms show themselves, and up to nine days after they have shown," said Gilbert.
Most people born after 1970 in the Maritimes have received a mumps vaccine. But those caught in the recent outbreak seem to be aged between 18 and 35.
Some officials have said youth should be given a second mumps vaccine to boost their immunity.
With a report from CTV Atlantic's Toby Koffman