Measles spread 'like wildfire' among unvaccinated children in northeast B.C., health officer says

A pocket of unvaccinated children in northeast B.C. allowed cases of measles in the region to spread "like wildfire," says B.C.'s deputy provincial health officer, Dr. Martin Lavoie.

He made the remarks during a provincial update on the disease that has seen multiple exposures reported in and around Fort St. John, including at an elementary school, emergency room and prenatal clinic.

"If the virus finds people who are not immunized, it will start infecting," Lavoie said during the July 10 presentation given to media.

Over the past weeks, he added, "the virus has found communities or pockets of population that are large enough in numbers to allow the virus to all of a sudden, I would say, explode or start like a wildfire ... and then it takes some time before it dies off and runs its course."

The risks of allowing it to spread, he said, included serious disease or even death.

According to provincial numbers, there is currently just one case of measles still active in the province. But as of July 8, 10 people were hospitalized due to the virus, with a total of 102 confirmed cases provincewide this year.

That's the highest number in more than a decade, though still significantly less than a 2014 outbreak centred around B.C.'s Fraser Valley that resulted in 344 confirmed cases.

In that case, the epicentre of the disease was at a school where about 360 students from kindergarten to grade 12 were infected, according to the B.C. Centre for Disease Control.

Lavoie said the outbreak in northeast B.C. had followed a similar pattern, with the first case believed to be travel-related.

From there, an exposure was reported at an elementary school in the community of Wonowon, around 90 kilometres northwest of Fort St. John. Subsequent exposures were then reported at shops and businesses, as well as at Fort St. John's emergency room and prenatal clinic for pregnant mothers.

The majority of those infected were under 18, provincial data shows, making up 70 per cent of known infections. The actual number is likely higher, Lavoie said, as many cases are known to go unreported.

Six of the 10 confirmed hospitalization cases in B.C. are located in Northern Health, with one in each of the four other health regions.

Lavoie said because the population of northeast B.C. is smaller than the Fraser Valley, he did not expect total infections to climb as high as they had in 2014, though he warned there was still a risk of travel-related infections bringing it to other locations.

He also noted that the virus was able to spread so successfully because it has been roughly 20 years since measles were in the region in any significant numbers, so there was an entire generation of unvaccinated people ready to be infected.