Tuberculosis cases are exploding Quebec: return of the infectious disease

Tuberculosis is making a marked comeback in the province. The Ministry of Health reports a 79% increase in cases in 2024 compared to the average of the five pre-pandemic years. Should we be alarmed by the resurgence of this disease which hit Quebec hard towards the end of the 19th century?

Since January 1, 442 cases of tuberculosis have been declared in the province, compared to 350 during the same period in 2023, according to data from the Ministry of Health and Social Services (MSSS) obtained by 24 hours.

The MSSS advises of a “significant excess” compared to the average of the five pre-pandemic years, i.e. 2015 to 2019, during which 247 annual cases were reported to public health authorities.

Between this period and 2024, cases of tuberculosis jumped by 79% in Quebec.

“We have seen an increase in the incidence of the disease for two or three years, immediately after the end of the pandemic,” confirms the director of the International Tuberculosis (TB) Center at McGill, Richard Menzies.

The regions of Montreal, Laval and Nunavik are particularly affected. The MSSS is carrying out increased monitoring of the situation there, it is said.

What is tuberculosis?

Tuberculosis is a disease requiring notification and treatment. All cases must be reported to Public Health and subject to an epidemiological investigation.

It can manifest as a latent or active infection.

In its latent version, it is not contagious and does not cause any symptoms. However, it can wake up months or even years after infection. About 90% of people who contract it will never develop tuberculosis.

In its active form, however, the disease can be fatal if left untreated. It mainly affects the lungs, in almost two thirds of cases, and can also affect different organs such as the bones, kidneys and the central nervous system.

It is this form which is on the rise in the province.

But be careful: contact with an infected person is not inevitably synonymous with contamination.

Tuberculosis is only contagious when the respiratory system is affected as transmission is by air, specifies 24 hours the spokesperson for the MSSS, Marie-Pierre Blier.

The disease is spread through the air when an infected person breathes, speaks, sings, sneezes or coughs, and is usually transmitted after prolonged contact of at least 12 hours.

Among the symptoms: a persistent cough that lasts more than two weeks, sometimes accompanied by blood and phlegm, chest pain, fatigue, loss of appetite and weight, chills, fever and night sweats.

“The treatment is not easy,” warns Dr. Menzies, “but it is effective. You have to take a lot of antibiotics over a long period of time: four drugs for two months and then two types of drugs for four months, every day. Preventive treatment is also administered to people who have been in contact with active tuberculosis.”

Upsurge all over the world

One might mistakenly believe that tuberculosis is an “old disease” belonging to a bygone era. However, we are observing an increase in cases all over the world.

Last October, the World Health Organization (WHO) reported that around 8.2 million new infections were diagnosed in 2023, the highest number ever recorded since the WHO began monitoring tuberculosis. It is now the deadliest infectious disease on the planet, surpassing COVID-19. In total, 1.25 million people died from it last year.

India, Indonesia, China, the Philippines and Pakistan alone accounted for 56% of the global TB burden, according to the WHO.

So what explains its spread in Quebec?

“The province has seen a significant increase in refugees and asylum seekers in recent years. Some come from countries where the incidence of tuberculosis is very high, others have lived in difficult conditions or in refugee camps. These are environments where transmission is greater,” explains Richard Menzies of the International Tuberculosis (TB) Center at McGill.

The expert assures, however, that a resurgence of the disease is not to be feared.

“New arrivals represent the majority of cases reported in recent years,” he emphasizes. The disease is detected in the months following their arrival in Quebec and up to two years later. The risks to the general population are minimal.”

Critical situation in Nunavik

Indigenous and Inuit people are also disproportionately affected by tuberculosis, according to the MSSS. The situation is particularly critical in Nunavik.

“The incidence rate of the disease is 300 times higher than that in the rest of Quebec,” indicates Dr. Menzies. In some villages, up to 2% of residents contract tuberculosis each year.”

The cause is multifactorial, according to the expert.

“The overcrowding of housing in communities and therefore of proximity is a risk factor. There is also the question of nutrition, the transition from a traditional diet to a southern diet for which it is difficult to obtain fresh and nutritious products in these remote regions. Diagnoses also take longer to obtain as the health system is restricted,” he explains.

In Nunavik, a vaccine is available free of charge for infants.

The French-Canadian White Death

With the exception of Inuit and Indigenous people, tuberculosis tends to continually decrease in the population born in Quebec and Canada, recalls Dr. Richard Menzies.

There was a time when what we call the “white plague” was nevertheless recognized as the “national” disease of French Canadians, explained historian Jean-François Nadeau on Ici - Première.

Between 1886 and 1906, tuberculosis caused 33,000 deaths according to figures from the Health Council of the province of Quebec. It was then responsible for almost a third of the mortality of the “productive population”, i.e. aged 20 to 45.

Industrialization and rapid urbanization partly explain the high casualty rate. The proximity of the population crowded together in the cities allowed the contagious disease to spread. Most of those infected lived in urban areas and worked in factories with poor hygiene.

Milk is also singled out. It is estimated that 10% of cows were then infected with bovine tuberculosis and produced contaminated milk. Pasteurization did not become compulsory until 1925.

The first Quebec sanatorium opened its doors to tuberculosis patients in 1908 in Sainte-Agathe-des-Monts. Several others will grow throughout the province. We understand at this time that patients must be isolated to slow the spread of infection.

Some people will spend up to 20 years there before healing, says Jean-François Nadeau. But the disease really began to decline with the arrival of antibiotics in the 1950s.