Dramatic measles outbreaks worry health officials

There have been 95 measles cases reported in Canada so far this year — with Quebec, Ontario and Manitoba reporting new cases in the last week, says Canada's chief public health officer. 

That's in contrast to 147 cases for all of last year. 

"The fact that … the numbers are growing this year demonstrates how this virus can spread if people were not vaccinated," Dr. Theresa Tam told CBC News on Tuesday. 

"What I would like to see is that we stop these outbreaks in their tracks so that it doesn't become entrenched in the Canadian context."

The most recent data from the Public Health Agency of Canada (PHAC) shows 34 new cases in the week of Feb 8, but that figure is already out of date because Ontario's outbreaks have grown. 

Tam says an outbreak that now spans several provinces began in October in New Brunswick.

The first person known to be infected in southwestern Ontario's Grand Erie Public Health region travelled to New Brunswick to attend a wedding, says the region's acting medical officer of health, Dr. Malcolm Lock.

"It's my understanding that a traveller infected with measles [from Europe] attended that wedding," Lock said. "Because of that, the disease was transmitted to a number of the people that were there, who in turn have now returned to their own communities, and if those communities are under-immunized then it's just a cascade."

The resulting outbreak in Brantford, Ont., and the surrounding counties is moving fast, Lock said, given that it started before Christmas and seemingly hasn't yet peaked. 

Measles is a highly contagious virus that's most dangerous to children under age five. 

The virus spreads easily through the air and can cause a hacking cough, high fever and a red, blotchy rash.

Measles can lead to high hospitalization rates. What's more, it is estimated nearly one to three of every 1,000 children who become infected will die from respiratory and neurological complications, such as pneumonia and brain damage. 

Speaking generally, Lock says measles can lead to "nasty complications, particularly in children of upper respiratory problems, pneumonia and in some cases meningitis and encephalitis." The problems can persist throughout life. 

Dr. Sarah Wilson, a public health physician with Public Health Ontario in Toronto, says the province expects to add 50 to 60 new cases in its update later this week. It is Ontario's largest outbreak in more than a quarter century.