Canada: Tuberculosis study in Nunavut tests new treatment for latent TB

One dose a week for 3 months could prevent dormant infections from becoming contagious

Dr. Gonzalo Alvarez, a lung specialist at the Ottawa Hospital and researcher with Taima TB, is leading the Nunavut-based study. The territory's rate of tuberculosis infection is 40 times the national average. 

"There is a huge opportunity," said Alvarez. "We want to be able to go upstream and help people before they get sick."

The study will test a new, shorter treatment for the latent form of tuberculosis, which develops into active TB for about one in every 10 patients. 

With active TB, "people start getting sick with the common symptoms that are weight loss, fever, night sweats, chronic cough, severe fatigue that people get — and people can die from this disease."

The new treatment

Currently, Nunavut treats the dormant infection with an antibiotic called isoniazid, which patients need to take twice a week for about nine months. 

The study would test a double drug treatment, combining isoniazid with another antibiotic, called rifapentine, which Health Canada has approved for use in this study. Taken together, the treatment requires only one dose a week and can be completed in three months. 

"It's a considerable difference," Alvarez said. "Many of our partners told us if there was something, if there was new research that could bring back the number of months and the number of doses we had to take, it would really help."

In fact, Alvarez's previous research showed that only half of Nunavut patients with latent TB chose to do the treatment. Of those patients, about 70 per cent completed it. 

Tuberculosis a 'major concern'

Last year, Nunavut residents contracted tuberculosis at a rate of about 143 cases per 100,000 people — the lowest rate since 2007. That's less than half the rate from 2010, where Nunavut saw about 328 cases per 100,000 people.

Nunavut Health Minister Monica Ell-Kanayuk said, as of last week, the territory has only seen three new cases this year. 

"I'm hoping the trend is that we're continuing to lower the tuberculosis rates in Nunavut," she said.

Still, Ell-Kanayuk says the disease is prevalent in Nunavut and a "major concern," given how people in the territory are subject to many risk factors for the disease, including overcrowding and poor nutrition.  

"Tuberculosis is still a significant problem," Alvarez agreed. 

"Without a doubt it does affect people who are affected by common risk factors that affect tuberculosis, such as poverty, crowding or poor housing, nutrition."

The Taima TB 3HP study is set to last 18 to 24 months and should include 225 people with latent TB in Iqaluit.

For now, the drug is not sold anywhere in Canada and is more expensive than the current treatment.

Source: CBC News