It was just another church exchange — a few members of the Reformed Congregation of North America in Chilliwack, B.C., visiting their brethren in Holland in January, as they've done so many times before.

This time, however, they arrived in the middle of a small measles outbreak in the country. And the members of the Reformed Congregation of North America don't believe in vaccinations.

By the end of March, there were 320 cases of the disease in B.C. The outbreak started at the church's Mount Cheam Christian School and spread through the community from there.

It's one of several outbreaks that have cropped up across the country this year, sounding the alarm on what was once considered a childhood disease now virtually wiped out by advances in vaccinations.

In 2002, measles was declared "eliminated" from the Americas.

Since then, due to people refusing shots, imported cases have made headway into Canada. Several cases across the country — reported in Alberta, Saskatchewan, Manitoba and Ontario — have been linked to travel to the Philippines.

Dr. John Spika, with the Public Health Agency of Canada (PHAC), says, despite a 95% coverage of the measles vaccine, clusters can still be expected in communities that have rejected them.

PHAC says there were 83 cases of measles in 2013, and only 10 in 2012.

Those numbers are nothing like previous generations, however.

Before a second dose of measles vaccine was introduced in 1996, ensuring 99% immunity, Canada still reported thousands of cases, Spika said, including more than 6,000 in 1991.

And before that, measles was a sickness many kids just had to live through, like chickenpox. Churches like the Reformed Congregation of North America, as well as other advocates against vaccinations, believe the immunity built up from battling through measles is worth the illness.

But there's a reason a vaccination was developed.

The most severe complication from measles is encephalitis, a swelling of the brain, which can lead to brain injury or deafness.

One third of children under five who contract the infection will need hospitalization.

Canada's Vaccine Risk Awareness Network says it's not against vaccines, but believes more information should be made available for people to make informed decisions, co-ordinator Edda West told QMI Agency via e-mail.

West, who says her youngest daughter had a severe adverse reaction to the measles, mumps, rubella (MMR) vaccine, says Canadians "are never provided full disclosure of the risks associated with vaccines."

West said the natural immunity that comes after having measles is a "precious health resource."

While the tiny minority of the population that refuses vaccinations don't put the general vaccinated public in any real danger, these small groups make it difficult to track the spread of the infection.

Dr. Paul Van Buynder, medical officer of health for the Fraser Valley, said public health didn't know about the outbreak until early March when some children sought medical care.

"Measles is often not reported in these groups," Van Buynder said.

The disease spreads quickly and efficiently.

The outbreak in B.C. remains mostly isolated to the community, but it's travelled to a branch of the church in Washington state.

Authorities have tried to keep it contained, though anyone outside the church who refuses vaccinations is still at risk.

Van Buynder is concerned with what appears to be a growing trend among some parents who choose not to vaccinate their kids because of concerns they hear on TV or the Internet.

"The messaging with pseudo-science is incorrect," he said. "They say there is a risk of autism or other serious consequences, when really the danger and damage occurs from the virus.

"These are nasty diseases we worked hard to get rid of and now they're coming back."