Alberta Health Services says 53 students and staff at a high school in the Calgary region may have been exposed to infectious tuberculosis.
TB is a bacterial disease that usually affects the lungs.
AHS says it has sent notification letters to the 53 people to arrange for them to be tested for TB, and for treatment if necessary.
It says the general public is not at risk, and the risk to the people who have been exposed to tuberculosis is low.
An AHS website says tuberculosis germs are spread to others through the air when a person with the disease coughs, sneezes or talks.
The Canadian Press