Alberta Health Services says that more than 100 people may have been exposed to measles in Banff. The agency says one person who tested positive for the disease was in the area last month while infectious.

Those who were at the OK Gift Shop at May 25 or 26 or at the IGA grocery store on May 30 during particular times may have been exposed to the highly contagious virus, according to a public health advisory issued Tuesday.

Yoshi Kimura, the general manager of the OK Gift Shop, told CTV Calgary that the man infected with measles is an employee at his store.

Kimura said the employee complained that he was experiencing flu-like symptoms and a blood test confirmed measles.

All of the staff who worked with the man at the gift shop have been sent home as a precaution, Kimura said.

Dr. Judy MacDonald from the AHS told CTV Calgary that “the concerning thing about this case is that there is no history of travel, so this measles must have come to him in Banff.”

Measles, which is spread through airborne transmission, is very contagious because its viral particles can live for hours in the air or on surfaces.

Initial symptoms include fever, cough, runny nose, red eyes and sleepiness. Small, white spots can appear in the mouth and throat and a blotchy red rash often appears on the body three to seven days after the fever starts.

“The scary thing is that you can be infectious even before you have symptoms,” MacDonald said.

There is no cure for the measles. However, it can be prevented through vaccinations which are provided free of charge in Alberta.

Most people recover from the measles within two to three weeks, according to Health Canada. The disease can be dangerous for infants and people with weakened immune systems.

The World Health Organizations says that measles is the leading killer of children whose deaths could have been prevented by vaccines.

The AHS says that those born after 1970 who have never had the measles or never been vaccinated for it, and who were in those two locations, should keep an eye out for symptoms.

Toronto Public Health said Tuesday that it, too, was investigating a confirmed case of measles in an adult who travelled to Toronto on May 30 via Kiev, Berlin and Reykjavik, Iceland.

With files from CTV Calgary