There Is Still Tuberculosis In Canada
Question: I recently heard that cases of TB are increasing in our province from new immigrants. This really scares me. Our three children are in school, and they have recent immigrants in their classes. Our middle child has arthritis, and may require treatment that can suppress her immune system. When I was young, my mother told me that her grandmother was in a TB sanatorium, and all the children had TB tests, and took medicine. I haven’t heard about TB again until recently; I thought we have eradicated TB in Canada. How much should we worry about our children getting infected with TB?
Answer:
Unfortunately, we have not eradicated tuberculosis (TB) in Canada. There have been outbreaks of TB across the country in recent years.
TB is caused by a bacterium called Mycobacterium tuberculosis. It only infects us, not our pets, or other animals. It spreads from infected people to others around, usually through indoor air, into the lungs. Once they land there, our immune system localizes the bacteria within the lungs. This stage is called TB infection (previously named latent TB). Although these people are infected, they are not contagious; they don’t spread the infection to others, and they are perfectly healthy. This is where the problem lies: they are healthy but infected, and they don’t even know it, unless they have specific tests for TB.
However, months or years later, when their immune system is weakened by malnutrition, advanced age, other infections like HIV that damage their immune system, or taking medications that suppress the immune system, the dormant TB bacteria can start to grow and multiply, invading neighbouring lung tissues and other organs. Then they become sick with TB disease (also called active TB): they can have fever, sweating, weight loss, and cough. This is the stage when they can spread the bacteria to others, usually through indoor air.
TB was very common in Canada in the first half of last century. We had sanatoriums to isolate those with TB disease, and reduce the spread of TB in communities. Improvement of nutrition and living conditions (less crowding in houses) also helped.
When antibiotics were invented, those with TB infection (latent TB) and TB disease (active TB) were able to be treated effectively, eradicating the bacteria in their body. As a result, TB became a rare condition in most parts of Canada in the last few decades. Unfortunately, incidence of TB infection and disease continued to remain high in many indigenous communities. In addition, those who have suppressed immune system are more susceptible, as well as those unhoused, or addicted to drugs.
Around the world, it is a different story. About one-third of the world’s population is infected, and over a million people die every year from TB. There are many barriers in screening, diagnosis, and treatment of those with TB in developing countries. The bacterium has also developed resistance to many antibiotics.
Fortunately, we have a very good public health system in Canada. All immigrants have chest X-ray and screening tests for TB before they can enter Canada. Refugees are required to have these tests as well shortly after they arrive. These would identify anyone who has TB infection, and treat them with antibiotics to prevent them from infecting others.
The government is also setting up screening programs in indigenous communities to identify those infected and provide them treatment. Other vulnerable groups, including unhoused people, those infected with HIV, etc, are also more susceptible to TB.
With so many in the world being infected with TB, it is almost impossible to completely prevent it from entering our borders. We have to stay vigilant and continue to screen and treat susceptible groups and individuals.
If your daughter requires medication that can affect her immune system, you should let her physician know. She may need screening test for TB before starting her on arthritis treatment.