Physicians brace for summer travel season as Alberta tops 800 measles cases

As summer approaches, Alberta's measles case counts are expected to keep climbing and some experts worry transmission will become even more widespread.

With 31 new cases reported over the weekend, Alberta's total case count jumped to 809 by midday Monday.

Five people are currently hospitalized due to the virus, including two patients who are in intensive care.

The outbreaks began in March and while cases have been confirmed in all zones, the south, central and north zones are the hardest hit.

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"This is not showing signs of slowing at this point," said Caroline Colijn, a professor and Canada Research Chair of Mathematics for Evolution, Infection and Public Health at Simon Fraser University.

She predicts  Alberta's measles case counts will keep climbing for months.

"I would expect it will continue to transmit and find pathways through our population to reach people who are not protected."

Dr. Sam Wong, president of the Alberta Medical Association's section of pediatrics, is worried about what's to come.

"In a few weeks' time, if the numbers keep going ... I think that we're going to hit over 1,000 [cases]. We're going to hit more measles cases in Alberta than they have in the States," said Wong.

According to the U.S. Centers for Disease Control and Prevention, 1,168 cases had been confirmed in the entire country, as of June 6.

"That is mind-boggling to me," Wong said. "And it speaks to the failure of the [Alberta]  government to do their job when they could have done it earlier on."

Summer travel

At the University of Calgary, Craig Jenne will be watching the trends in the coming weeks.

He's concerned summer activities, such as travel, could spark even more widespread transmission.

"As we get into the next several weeks people will be starting summer vacations. We will see festivals ... Calgary Stampede is in a few weeks. We may then see community level transmission expand beyond the south zone," said Jenne, a professor in the department of microbiology, immunology and infectious diseases.

Experts say a single case of measles transported into an area with low vaccination rates is akin to a spark landing in a tinder dry forest.

"I think travel between and among communities with low immunization ... will allow the virus a path to get into a new, close-knit community where vaccination rates are low," said Colijn.

The south zone accounts for 71.6 per cent of Alberta's total cases.

A standing exposure advisory remains in effect for that part of the province due to widespread transmission.

Health officials have warned official case counts are the "tip of the iceberg" in southern Alberta due to unreported and undetected cases.

Dr. Paul Parks is seeing that firsthand in the Medicine Hat emergency room where he works.

He, too, is bracing for further outbreaks in the province.

"It's such a contagious illness," said Parks, who is also the past-president of the Alberta Medical Association.

"As people are out at mass gathering events and as Stampede comes and as all these different events happen, we're going to have more and more spread."

The measles virus can hang in the air for several hours after an infected person leaves a location.

More than 90 per cent of people who are not immune and are exposed to the virus will end up infected, according to the Alberta government.

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"The other thing to think about is ... Alberta could be a source of measles introductions to other places," said Colijn.

"We may see a broader geographic spread because of summer travel from Alberta more than to Alberta. That's very hard to predict."

The vast majority of Alberta's cases are among unimmunized individuals, provincial data shows.

Measles can lead to serious complications including pneumonia, brain inflammation, premature delivery and even death.

Children under the age of five, people with weakened immune systems and pregnant individuals are at the highest risk of severe complications.

The province says 64 Albertans have been hospitalized due to measles this year, as of May 31.

Ten of those people have ended up in intensive care.