Eastern Health's medical officer says it does not believe the case of tuberculosis discovered at Holy Heart of Mary High School in St. John's this week is widespread.

Dr. David Allison said there are not many cases of TB in the province — around half a dozen a year.

He said he could not provide details about how the student got the disease due to confidentiality, but officials are trying to discover the source.

"Basically, what we have to do is put together information about the various risk factors that might go along with this, for example aboriginal populations or people who have come from foreign countries, or in fact Newfoundlanders have a history of exposure to tuberculosis,' Allison said.

"There [are] situations that arise that we need to be very alert to the signs and symptoms of it."

Allison said the health authority is confident that it caught the illness in time to get it properly treated, and they will be testing people who may have been in close contact with the illness.

"We first look at the immediate household situation and closest friends, and then we use concentric circles to build out," Allison said.

"We've identified a couple of classrooms where the student has attended that we need to pay attention to, and so we'll be doing some skin testing next week in a couple of classrooms to see if there is any possibility it spread," he added.

Allison said parents of students who may be at risk will also be contacted by Eastern Health.