While tuberculosis (TB) is considered a disease of the past, the rates in Saskatchewan are multiple times the national average, and the largest single cause of death due to an infectious disease agent.
Mycobacterium tuberculosis, the germ that causes TB, was first discovered by Robert Koch on March 24, 1882. Now, researchers at the Vaccine and Infectious Diseases Organization (VIDO) in Saskatoon are carrying on that legacy of lifesaving research.
“Almost, like, 1.5 million people die of TB every year,” said Neeraj Dhar, principal research scientist at VIDO.
“Ten million new infections and two billion of the world’s population carry it in a latent form. So, it can spread.”
Rates in Canada are lower than in other countries, but they’re alarmingly high in Saskatchewan, Manitoba and Nunavut, researchers say.
“In Canada it’s roughly 5.1 out of 100,000,” said Jeffrey Chen, principal research scientist at VIDO. “But in Saskatchewan, it’s closer to 10.9 out of 100,000, so the rates are higher.”
Chen says cases tend to be concentrated in the northern part of the province where risk factors like food insecurity, crowded housing conditions and a lack of access to healthcare make transmission easier.
While there is a treatment regime, it takes six to nine months to complete, and comes with unpleasant side effects, like liver toxicity.
“Because it’s quite toxic, like it damages the liver with these antibiotics,” said Dhar. “So you have to be on a strict diet, you cannot take alcohol for example, nausea is a common symptom.”
Chen says patients often stop their treatment once they start feeling symptoms going away, and that can lead to more problems.
“As soon as they feel better, they will stop,” said Chen. “And they may not complete that multi-month regimen. If you don’t take your full antibiotic dose, that can give rise to antibiotic resistance in the bacteria. And so this has become a big problem.”
Dhar says symptoms of TB were often overlooked during the COVID-19 pandemic, as resources like healthcare workers, reagents and testing were diverted to the immediate threat.
“TB was very much in control until COVID hit,” he said. “We were on track, rates had fallen down, but then once COVID hit, all the progress that the world made in the last almost 10, 15 years was all reversed.”
The current vaccine for TB is around 100-years-old, says Chen.
“This vaccine works, it is very effective in newborn infants and newborn babies, however the vaccine doesn’t really work in adults, where you have the most cases of TB,” he said.
“So there is now a push towards developing vaccines that actually prevent TB in the adult population.”
And since the organism is a slow growing one, research into more effective vaccines and drug resistant treatments for TB have to be slow as well.
“Yes it is slow going,” said Chen. “But we are optimistic that in a couple of years, we should have a few candidate vaccines to take into further clinical trials. And the same is true for some of the drugs that we are working on, in collaboration with a number of other labs and collaborators in Canada and outside of Canada.”
The province says the number of tuberculosis cases per year is on a decline.
“In 2023, there were 142 TB cases in Saskatchewan,” the Ministry of Health told CTV News in a statement.
“The number of cases in 2023 declined in comparison to 146 cases in 2022, and preliminary numbers for 2024 suggest the downward trend is continuing. Addressing TB requires coordination and co-operation among TB Prevention and Control Saskatchewan, the Saskatchewan Health Authority, the provincial and federal governments, including Indigenous Services Canada, the Northern Inter-Tribal Health Authority and other sectors.”
