What we can learn from the current measles outbreak in B.C.
Thirteen people in Vancouver so far have caught the measles — a disease that was technically eliminated in Canada in 1998.
The potentially-dangerous disease keeps cropping up though, usually brought by travellers from abroad. And this outbreak, like others before it, shows us something about vaccinations and disease in our country.
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This year’s outbreak is in Vancouver. In 2017, Nova Scotia had more than 20 cases. In 2015, there was a big outbreak in the Lanaudière region of Quebec.
“We get importations every year actually,” said Dr. Theresa Tam, the chief public health officer of Canada. “And some years more than others. It’s a constant risk.”
Usually, these cases don’t spread very far. But every so often, such as in Quebec, the virus hits a pocket of under-immunized people and runs through the community. “If you introduce the measles virus into any pocket, even a small one, it is going to very likely see other cases,” Tam said.
This happened in some schools in Vancouver this year, where not enough children were immunized and some caught the virus.
As long as vaccination coverage in Canada remains the way it is, Tam expects to see more small outbreaks in the future.
Vaccination coverage in Canada is uneven
Overall, Canada’s measles vaccination rate is about 89 per cent, according to a 2015 Statistics Canada survey.
This is a bit lower than the U.S., where it was about 91.5 per cent in 2017, according to the Centers for Disease Control.
“I’m never proud when I go out of country,” said Dr. Noni MacDonald, a professor of pediatric infectious diseases at Dalhousie University. “I do a fair amount of advisory work with the World Health Organization in many countries in many different regions. And Canada does not have a stellar record for vaccination acceptance.”
To protect the population from measles, the vaccination rate needs to be above 95 per cent, she said.
Some parts of Canada reach that rate, but there are “pockets” of under-vaccination, which are vulnerable to disease, Tam said.
“What we do need to know is exactly where pockets of under-immunizations exist, which you’re not going to get from a national-level survey for instance,” she said. Right now in Canada, each province maintains its own vaccination registry, and they all track immunizations a bit differently.
Vaccine concerns often present in clusters, MacDonald said. If you’re hesitant about vaccination yourself, she said, it’s likely that people around you feel the same way.
“You cannot assume, for example with measles, that even though you didn’t get your kid immunized, your kid is going to be fine because everyone else in your child’s school got immunized,” she said. It’s likely that other parents at the school also haven’t gotten their children immunized either.
What health authorities definitely don’t want is for pockets to get wider.
“It doesn’t take much for vaccine coverage to go down a bit more and for these pockets to widen,” Tam said. “So I think it’s something we need to be highly vigilant for and do something now to prevent that.”
People — including doctors — don’t always recognize the signs
In Vancouver, health authorities warned people that they might have been exposed to measles in a children’s hospital emergency room on several separate occasions.
One mother, whose child was eventually diagnosed with measles, told Global News that doctors at another hospital initially misdiagnosed her child — possibly exposing more people to the contagious disease.
The Fraser Health Authority told Global News that it had conducted an investigation into the case and determined there was no wider risk to the public and contacted people who were at the hospital directly.
While she couldn’t comment on the specific cases, Tam said that doctors are sometimes unfamiliar with what measles looks like.
“Just as parents haven’t seen vaccine-preventable diseases because of how effective childhood vaccines are, there’s a whole generation of medical professionals who also haven’t seen measles.”
MacDonald agrees. “Part of the problem is, many of the young physicians and nurses have never seen cases. So they don’t go, ‘Kaboom, it’s mumps. Kaboom, it’s measles.’ And don’t necessarily recognize it as soon as they should.”
Doctors need to familiarize themselves with the symptoms of measles and take a detailed travel history of people who are showing them, Tam said, so the patients can be properly isolated.
Medical schools need more training on these vaccine-preventable diseases, MacDonald said. “Immunization is so important to health outcomes that this should not be delegated off to a half hour in one little section and not made to be as important.”
She’d also like to see children in elementary and high school learn about these diseases and vaccination. “I think kids need to learn about this so that they’re going to grow up to be knowledgeable about why we’re doing this, and why it’s so important.”
Tam doesn’t want vaccination rates to drop and hopes more public education will help. “We need to be really concerned and vigilant right now not to really lose the hard-won gains that we have for several decades,” she said.
“It took us time to get here. It may not take much for us to lose it.”
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