All staff at a New Brunswick fish processing plant are being tested for tuberculosis after one of its employees tested positive for the disease last week.
Public Health informed True North Salmon Company that an employee at its Blacks Harbour plant tested positive for active tuberculosis last Thursday, said Joel Richardson, spokesperson for Cooke Aquaculture, which owns True North Salmon.
Richardson said a team from Public Health was at the plant on Tuesday and Wednesday testing employees, with the results expected to come in starting Thursday.
"We're very grateful that all of our 87 employees have co-operated fully with Public Health to be screened for symptoms, and any employees who have been contacted for testing are required to complete testing this week before being permitted to resume work," he said.
Watch| All staff at Blacks Harbour fish processing plant being tested for tuberculosis:
Tuberculosis, also known as TB, is caused by the bacteria mycobacterium tuberculosis and is spread from person to person through the air, according to a New Brunswick Public Health fact sheet about the disease.
The bacteria are spread from person to person through coughing, sneezing and talking when in close, frequent and prolonged contact with someone who has active TB, according to Public Health.
Richardson said the employee had been off work sick for about two weeks prior to testing positive.
He said Public Health determined through contact tracing that the risk to other employees and to the wider community was "low," and therefore a notification for the region wasn't required.
Richardson said the employee is currently in hospital and is expected to recover.
CBC News has asked Public Health whether any more cases have been detected and whether any possible exposure sites were identified.
In an email, spokesperson Sean Hatchard said Public Health cannot comment on specifics, but that any exposed individuals are contacted directly.
"It is also common for Public Health to work closely with businesses and organizations who may have a confirmed case," he said.
He said general symptoms can include loss of appetite, weight loss, fatigue, fever, high sweats, prolonged cough and chest pain.
Richardson said Public Health officials told the company that the employee doesn't appear to have contracted tuberculosis from the community.
Richardson said the employee also didn't travel outside of the region in recent weeks.
Richardson said the only explanation for its source is that the employee had a latent case of TB, which only recently became active.
"Our understanding from talking to the medical officers is that some forms of tuberculosis can actually be dormant in individuals even if they've previously been vaccinated as children, and that's the case with this particular individual."
Not uncommon scenario, expert says
TB cases can either be "active" or "latent," said Dr. Isaac Bogoch, an infectious diseases specialist based out of the Toronto General Hospital.
A latent case occurs when the bacteria that causes TB enters someone's body, but their immune system effectively fights it off.
The bacteria, however, can remain dormant in the body for decades, and up to 10 per cent of the time will at some point turn into an active case, with the person exhibiting symptoms such as cough and fever.
"That's like the norm. That's what happens the vast majority of the time," Bogoch said.
"There's certain parts of the world where TB is much more common compared to Canada, and many people are exposed to this infection early in life and they developed what's called latent tuberculosis … and they don't know they have it."
While TB can bring about severe symptoms, Bogoch said the treatment options available in Canada are very effective.
"You have to start off usually on four different antibiotics — four different pills — and you treat for a minimum of six months to ensure that it's treated … and again, it's not that hard to treat if you know what you're doing."
Increasing mask usage
Richardson said employees were already required to wear masks while on the processing line.
However, with the confirmed case of TB, the company is currently requiring employees wear a mask as soon as they enter the plant.
Richardson said operations at the plant otherwise have not been affected.