Toronto Public Health has confirmed a fifth case of measles in Toronto in the past four weeks.
The city agency says four of the five cases are linked to the Ontario Science Centre, including the most recent infected person.
Anyone who attended the facility on April 2 before 1:30 p.m. is being cautioned to watch for symptoms of measles.
These symptoms include cough, runny nose, fever, white spots in the mouth and red watery eyes that are sensitive to light. The symptoms are then followed by a red rash that lasts about six days.
If symptoms develop, infected persons are asked to seek medical attention and call ahead and advise the medical facility they have been exposed to measles.
The health agency says the city is experiencing an outbreak of measles as Toronto usually only deals with three reported cases each year.
Measles is highly contagious and can be spread between two people talking or even just standing in close proximity to an infected person.
Most people who get measles are sick for about 10 days and recover completely without any treatment.
The danger to the overall public is low, medical officials say.
"The risk to the general public is considered low because of Canada's high immunization rates and high immunity among the population," the health agency states on its website.
Children under the age of five, pregnant women and those with weakened immune systems are at the greatest risk of infection.
