print header

World TB Day Myths and Facts

Myth #1:  TB is highly infectious.

Fact: TB infection actually requires prolonged, indoor, and close contact to a person who is showing symptoms of active TB disease.

The detailed explanation:

Tuberculosis is a disease often called TB. It is spread by bacteria (germs) that can float in the air. The TB bacteria or germs may spray into the air if a person with TB disease in the lungs talks, coughs, sings or sneezes. People nearby can breathe TB germs into their lungs and get TB infection. When you are just infected, but not sick, you are generally not contagious.  If you have symptoms, then you have TB disease.

If the TB disease is in your lungs, you may:

  • cough a lot
  • cough up mucus or phlegm or blood
  • have chest pain when you cough or breathe. 

If you have TB disease anywhere in your body including the lungs, you may:

  • have a fever
  • sweat at night
  • lose your appetite
  • lose weight
  • feel weak
  • have pain or swelling in the part of your body with the TB disease.

TB is not considered to be highly infectious.  To catch it normally requires prolonged, frequent, and close contact with someone who is ill with active tuberculosis disease.  If a person who is actively sick with tuberculosis goes untreated for a long period of time however, they can still infect a high number of other people.

For more information please see the most recent Canadian Tuberculosis Standards

Or see the Ontario Public Health Standards 

Myth #2: Every person who is infected with TB is contagious.

Fact: Most people who are infected have immune systems that can “wall off” the TB into capsules so that it isn’t harming anyone. 

The detailed explanation:

In most people, TB infection is contained by a person’s immune system, and the infection remains latent, or “walled-off”—at least to start with. However, latent infection can develop into active disease at any time.  There are some risk factors, such as HIV, that can increase your risk of developing active TB.  About 90% of latent TB infections don’t ever make people sick.  About 5% will become active in the first two years after the initial infection, and about  5% will become active after the first two years.

For more information please see 

Canadian Tuberculosis Standards

Myth #3:
TB is a fatal diagnosis.

Fact: TB is curable, in both its latent (walled-off) and active forms. TB is slow-growing though, so the medications MUST be taken for the full course. 

The detailed explanation:

According to the most recent report available, there were 1,614 people in Canada diagnosed with active TB disease in 2012 and 87% were cured or completed treatment.

Please see the Public Health Agency of Canada’s report for more information

Myth #4: TB is something from Canada’s past: the incidence rates are so low here, that it doesn’t get much attention.

Fact: Fortunately the rates are low here, however the national rate is 4.7 per100,000 Canadians, which is still too high for a curable disease.

The detailed explanation:

Worldwide, it is estimated that there is a rate of 128 cases per 100,000 population.  Canada’srate is 4.7 per 100,000 population.  There has not been a significant rise or fall in the number of reported TB cases between 2003 and 2013.

Please see the Public Health Agency of Canada’s report for more information

Or the Canadian Tuberculosis Standards

Myth #5: TB is exclusively a lung disease.

Fact: TB can infect nearly any part of the body, and it’s estimated that up 25% of active TB cases involve areas outside the lungs.

The detailed explanation:

Please see the Public Health Agency of Canada’s report for more information

Or the Canadian Tuberculosis Standards

Myth #6: TB infection is the same as TB disease.

Fact: TB infection is dormant, not contagious; in contrast, TB disease occurs when a person’s actively sick and at risk of infecting others.

The detailed explanation:

Chart of symptoms of contagious or non contagious TB

Please see our website for more information

Myth #7: A person with active TB will always have a tuberculosis skin test, or TST, that is positive.

Fact: A TST isn’t a reliable indicator of active TB: it’s as often positive as it is negative.  A chest X-ray and other tests may be needed.

The detailed explanation:

Tuberculosis skin tests are useful tools in diagnosing a latent tuberculosis infection, however, they are not used to find active tuberculosis as it can produce a ‘false negative’ in up to 25% of cases.  In Canada, the standard testing procedure for active TB disease includes a chest X-ray and sputum (saliva) samples.

A skin test on your arm is the best way to find out if you have TB infection.  A small needle is inserted just under the skin on your forearm, where the serum is injected.  A small white lump will form as the serum is given. You will be asked to return in 48-72 hours for the nurse to examine the test area on your arm. The test is "positive" if a swelling approximately the size of a dime or bigger is present at that time. This means you probably have TB infection.

For more information please see: 

The TB fact sheet on our website

Canadian Tuberculosis Standards
Ontario Public Health Standards 

Did you find what you were looking for today?
What did you like about this page?
How can we improve this page?

If you have any questions or concerns that require a response, please contact Health Connection directly.

Thanks for your feedback.
Failed to submit comment. Please try submitting again or contact us at the Health Unit.
Comment already submitted ...