The Vitalité Health Network says some people in Moncton may have been exposed to a potentially highly contagious type of tuberculosis.

Tests have confirmed a patient at the Dr.-Georges-L.-Dumont University Hospital Centre is suffering from laryngeal tuberculosis, officials announced on Monday.

Isolation measures were taken as soon as the diagnosis was confirmed on Sept. 17, they said.

But the risk of infection to those previously exposed, such as medical and paramedical staff members, patients and visitors, is unclear, said Dr. Gabriel Girouard, a microbiologist and infectious disease specialist.

It varies depending on the extent and time of exposure, he said.

Vitalité Health Network announces confirmed case of laryngeal tuberculosis in Moncton

The Vitalité Health Network says registered patients who may have been exposed to the infected patient will receive a letter informing them. (Kate Letterick/CBC)

The patient was admitted on Sept. 10.

“We were able to identify the dates on which we feel the risk of exposure was significant. At this time we are drawing up a list of individuals who were potentially exposed," said Girouard.

'We cannot reach everybody, so we did a very good effort and a lot of people are notified as of today and know and some have been tested.' - Dr. Gabriel Girouard, microbiologist and infectious disease specialist

It could be about 100 people, he said.

"It is very likely that several of these individuals will not require any screening or medical follow-up,” Girouard stressed.

Patients who were registered at the emergency department, in radiology, and at the blood test clinic of the hospital during the periods of time identified will receive a letter from the hospital informing them they may have been exposed to tuberculosis and should call 506-862-3767.

Although the public was only notified on Monday, health officials have been busy working behind the scenes, said Girouard.

"Why did we wait until the 23rd? I mean, we've been working on this case since the 18th and actively searching [for] patients, visitors — all this has already been taken care of we just need a little bit of extra to go reach some potential people that we're not able to contact," he said.

"What we know is that we cannot reach everybody, so we did a very good effort and a lot of people are notified as of today and know and some have been tested. Some needed to be tested, they have been tested."

Meanwhile, the infected patient has been showing clinical signs of improvement since treatment was started, said Girouard.

Officials don't yet know how the person contracted the disease, said Dr. Yves Leger, the regional medical officer of health.

"Obviously we're following up with the patient at this point and doing the routine public health followup that we would do and sometimes we are not able to, actually, most often we are not able to say exactly for sure when the patient was infected," he said.

Disease spread through the air

TB claims more than a million lives a year worldwide, but has largely been eradicated in North America.

New Brunswick's incidence rate is among the lowest of the provinces and territories, with an average of six TB cases reported per year since 2005, according to a 2011 report by the Office of the Chief Medical Officer of Health.

TB is caused by the bacteria mycobacterium tuberculosis and is spread from person to person through the air. When someone with active TB coughs, sneezes, or sometimes even talks, tiny droplets containing TB germs are released into the air, where they can remain for hours.

The bacteria usually attack the lungs, but can also affect other parts of the body, such as the brain, kidneys, lymph nodes and spine.

Symptoms of TB infection may include loss of appetite, weight loss, fatigue, fever or night sweats. However, many people can carry the bacteria for a long time and not have any symptoms.

TB is treated by taking several drugs for up to one year.