A case of tuberculosis has been confirmed at a Scarborough high school, Toronto Public Health says, but school officials are not saying whether the infected individual is a student, a teacher or an employee at the school.

The agency said Friday the infected individual is from Mary Ward Catholic Secondary School, located near Kennedy Road and McNicoll Avenue. The person was diagnosed on Thursday.

TPH said Friday it is following up with approximately 20 people at the school who came in direct contact with the individual.

The general school population is at low risk for exposure, TPH said, so anyone who has had casual contact with the infected individual does not require medical testing.

In a letter sent home to parents and guardians, school principal Andrea Magee said the school has arranged for additional cleaning and disinfection of common areas, including desks, stair handles and telephones.

Meanwhile, health officials say the individual was “doing well” and receiving treatment at home Friday. The school board said it doesn’t currently know how the individual contracted tuberculosis.

Although school officials say the situation is under control, some parents expressed concern.

“In Canada, I would have thought these diseases would have been controlled by now,” said Aloma Coutinho.

The school has offered to meet with parents next week to answer any questions.

Tuberculosis is an infectious disease and can be spread through the air. While there is a low risk of exposure, a person can become infected after close or prolonged contact with an infected individual.

Symptoms include weight loss, fever, chills, night sweats, fatigue and a cough that lasts more than three weeks.

Tuberculosis can be treated and cured with medication.

According to TPH, Toronto has approximately 300 active cases of tuberculosis each year. Of those, 12 are school exposures.

With a report from CTV Toronto’s Naomi Parness