Some students and staff at an Ottawa high school have been warned they may have been exposed to tuberculosis earlier this year.

Ottawa Public Health (OPH) announced Tuesday it's reaching out to about 150 students and a few staff members at Ridgemont High School in south Ottawa that they may have been exposed to the potentially serious infectious disease between early September and mid-November.

"The potential exposure would be whether or not somebody has spent a significant amount of time with the actual case," said Pam Oickle, infectious disease program manager for OPH.

"We work very closely with the school to identify all the classes that this student attended. All of those students and teachers have been identified and received a letter."

OPH is recommending they take part in tuberculosis testing at the school next week.

The agency said an unidentified student with active tuberculosis was at the school between Tuesday, Sept. 4, and Monday, Nov. 12.

OPH isn't aware of anyone who's currently infectious working or studying at the school, so there's no indication the infection spread.

"The one good thing with latent tuberculosis is that it is an infection that is easily treated," Oickle said.

"Our primary concern is ensuring that nobody actually goes on to develop active infection."

This is the 42nd case of tuberculosis in Ottawa this year, which OPH said is on par with the number in the last few years.

Pam Oickle of Ottawa Public Health explains how tuberculosis is transmitted, and how the department is responding to a case in an unidentified person with a connection to a local high school. 0:39

Not always infectious

Tuberculosis is an infectious bacterial disease that usually affects the lungs, causing coughing or sneezing that also spreads the bacteria.

It can also affect other parts of the body and cause other symptoms such as loss of appetite or weight, fatigue and fever.

It's possible for someone to have tuberculosis without it being active or infectious.

At an information session held at the school Thursday, health officials told parents they are expecting some tests will come back positive — though those cases may be related to exposure in a different setting than the school.

OPH said there will be follow-up screening for people who come in contact with additional cases.

Cindy Jadayel, chair of the school council, said many parents did not have a lot of information about the disease, such as the fact that it is treatable.

The meeting was also attended by local public school board trustee Chris Ellis and Coun. Jean Cloutier.

Anyone with questions can also call Ottawa Public Health at 613-580-2424 ext. 24224.