TB is a contagious disease caused by TB germs. TB usually attacks the lungs but can affect any part of the body. TB has been around for centuries.

Close, prolonged or regular contact with someone who is sick with TB disease is needed to spread the disease. It spreads from person to person through the air only when someone who is sick with active TB disease in the lungs coughs, talks, sings or sneezes.

TB is not highly contagious. TB is not spread by sharing utensils, plates, cups, clothing, bed linen, furniture, toilets, by shaking hands or by touching surfaces that have been touched by someone with TB.

People whose TB is in another part of the body (for example, glands/lymph nodes) cannot spread the TB germs to others.

Most people who breathe in the TB germs are able to stop them from growing. Most people’s immune systems trap the TB germs and keep them inactive. This is called latent TB infection (LTBI).

People with LTBI do not feel sick and do not have any symptoms, but usually, have a positive reaction to the tuberculin skin test. People with LTBI cannot pass the germs to others.

There is treatment for latent TB infection to prevent TB disease

TB germs become active when the body’s immune system cannot stop the germs from growing. The active TB germs begin to grow and cause damage to the body.

The general symptoms of active TB Disease include:

  • New or worsening cough that lasts for more than 3 weeks or keeps getting worse
  • Feelings of tiredness or weakness
  • Unexplained weight loss
  • Fever
  • Chills
  • Night sweats
  • Others (based on where the TB germs are located in the body)

If you think you may have TB see your healthcare provider.  TB treatment and medication are free in Ontario. For more information or if you have any questions Toronto Public Health at 416-338-7600.

A person with latent TB infection

  • Usually, has a positive TB skin test result
  • Has a normal chest x-ray
  • Has TB bacteria in his/her body that are inactive
  • Does not feel sick
  • Cannot spread TB bacteria to others
  • Can get treatment for latent TB infection to prevent TB disease

A person with active TB disease

  • Usually, has a positive TB skin test result
  • May have an abnormal chest x-ray, and/or positive sputum test for TB
  • Has TB bacteria in his/her body that are active
  • Usually feels sick
  • May spread TB bacteria to others if TB is in the lungs or throat
  • Needs treatment for active TB disease

  • People who have lived or travelled to countries where TB is common
  • Seniors
  • People who have lived on a First Nations reserve or Inuit community
  • People who are homeless or under-housed
  • People who live or work in residential settings (jails, nursing homes, shelters)
  • People who have HIV/AIDS

TB germs usually affects the lungs and can cause a disease called pulmonary tuberculosis. TB is spread when a person with TB disease in the lungs coughs or sneezes, and you breathe in the TB germs. First, the germs go to your lungs.

From there, they can go to other parts of your body through the blood stream and may affect other parts of the body, such as the bones, lymph nodes, kidneys, the stomach, the spine or the brain. This type of TB is called extrapulmonary TB. The most common site for extrapulomonary disease is in the lymph nodes (glands).

People with TB outside the lungs (extrapulmonary TB) cannot give TB to others.

This information is also available in the following languages. To request a copy, email us at targettb@toronto.ca or call416-338-7600 and ask for the TB program.

العربية / Arabic
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हिन्दी / Hindi
Magyar nyelv / Hungarian
한국어 / Korean
Polski / Polish
Português /  Portuguese
ਪੰਜਾਬੀ / Punjabi
Românește / Romanian

русский / Russian

Afsoomaali / Somali
Español / Spanish
தமிழ் / Tamil

བོད་སྐད་ / Tibetan
اردو / Urdu
Tiếng Việt / Vietnamese