Three Toronto residents have been diagnosed with mumps in the ongoing infectious disease outbreak that began in Halifax in February.

Toronto Public Health confirmed Tuesday that two of the individuals recently returned from university in Halifax, while the third came in close contact with one of the two students.

Nova Scotia has had the bulk of the cases, with 222 confirmed as of last Friday.

"It was pretty painful," said patient Dan Murray, an engineering student at Dalhousie University who recently returned to Ontario, where he was diagnosed with the disease.

"I had a headache for a few days."

New Brunswick, Prince Edward Island, Ontario and British Columbia have also seen cases in people who can be linked to the Nova Scotia outbreak.

"The numbers are concerning in Nova Scotia but if you look at what's going on in Toronto so far, we have three confirmed cases and a few more in the area under investigation," Dr. Neil Rau, an infectious diseases specialist, told CTV Newsnet. "But still, nothing on the scale of what Nova Scotia has."

Murray travelled to the University of Manitoba in Winnipeg to play volleyball, before he knew he was infected, so the virus may have spread to that province as well.

"There were 30 guys there, high-fiving," he said. "You're playing with the same balls, using the same weights. I was in contact with all of them, so they're all pretty much at risk."

It is believed that most of the cases are young adults who would have only received one dose of the measles, mumps and rubella (MMR) vaccine in childhood.

"Because of the outbreak among this age group in the east coast, Toronto Public Health is also asking all students who have returned to Toronto from the east coast to watch for signs and symptoms of mumps," Dr. Barbara Yaffe, director of Communicable Disease Control with Toronto Public Health, said Tuesday.

These students are urged to check their immunization status and consider getting a booster shot if they received only one dose of MMR.

Toronto Public Health said the third young adult infected with mumps spent several hours at a downtown restaurant and may have unknowingly spread the virus to others.

Those who visited the Supermarket Restaurant and Bar at 268 Augusta Ave. on May 10, between 9 p.m. and 3 a.m., are asked to watch for signs and symptoms of the mumps.

Symptoms include aches, pains, fatigue, fever, loss of appetite and, in about 40 per cent of cases, the hugely swollen saliva glands that give mumps its characteristic chipmunk-cheek look.

Toronto Public Health investigators have been unable to identify all of the individuals who shared drinks or cigarettes with this ill person to inform them of their potential exposure to mumps.

Most people who get the mumps recover fully within two weeks. Serious illness associated with the mumps is rare.

In very rare cases the disease can cause encephalitis, meningitis, and orchitis (inflammation of the lining of the testicles) in men. Pregnant women who become infected with mumps during the first three months of pregnancy are at risk of miscarriage.

Mumps is rare in Toronto, and on average only five cases are reported each year.

Since the mid-1990s, jurisdictions have moved to a two-dose regime after learning that one dose wasn't sufficient to protect against infection for some people.

However, Rau said people 40 or older may not be at a greater risk for mumps, because they could have immunity from a previous exposure.

"The people who are 40 (or over) have already seen the disease, the so-called wild-type disease, so they got immunity just by exposure to that," he said.

At least one province, Nova Scotia, is planning a catch-up campaign to offer a second dose of the vaccine to health-care workers and to university-aged young adults.

For information on the vaccine, call Toronto Public Health at 416-338-7600 or visit their website.

With files from CTV's Avis Favaro, Elizabeth St. Philip and The Canadian Press