More than 30 people have been diagnosed with whooping cough in Whitehorse since early June and Brendan Hanley, the territory's chief medical officer of health, expects more will soon be diagnosed — possibly in rural areas as well as the capital.
"We're getting regular reports of confirmed cases," he said. "We feel this outbreak or epidemic has not yet peaked."
Most of those ill have been between the ages of 12 and 17, though there have been some cases of adults in their 50s and children as young as six months old.
Whooping cough, or pertussis, is not life-threatening in a healthy adult. However, it can cause severe complications for young children or people with other health conditions.
Every year Canada sees one to three deaths from the disease. The most effective means of controlling and preventing whooping cough is through immunization.
Immunizations against whooping cough are available in Yukon, but the participation rate is roughly 85 per cent, said Hanley.
He would like to see the rate at 95 per cent.
"I would say there's a tiny minority, as everywhere else, that are just vehemently opposed to vaccines," Hanley said. "The vast majority of people are just out of date, they're people who forget. They haven't gotten around to it. They're busy parents, busy families. That`s the biggest category."
While vaccination is not an absolute guarantee against getting sick, Hanley said, immunizaton has been proven to work by creating herd immunity in populations.
"Even if we had the highest level of vaccination possible, we may still see pertussis. But we'd see a lesser impact."
Stay home if symptoms appear
Whooping cough is spread by direct contact such as being exposed to someone coughing or touching a person's secretions like a used tissue.
Hanley said people should stay home if they show symptoms or keep their children home.
He also advises people to seek advice from their doctor if they feel ill and make sure their immunizations are up to date.
For most people, pertussis is treated with antibiotics.
"For people who don't have underlying medical conditions, it's generally no more than a nuisance. It can go on for several weeks.
"Where we really put the emphasis is that young infants are at risk for complications. That's why we put out all this messaging. If the baby's under a year of age — especially those babies who haven't had a chance to have their first set of immunizations — they're more vulnerable to getting the severe complications."