What is TB infection?
- TB bacteria can live in the body without making you sick. This is called TB infection.
- TB bacteria are put into the air when a person with respiratory TB disease coughs, sneezes, speaks, or sings. People nearby may breathe in these bacteria and become infected.
- Your body's immune system stops the germs from growing by building a wall around the germs. The germs are "inactive" or "sleeping" when this happens, and you will not be sick or have any symptoms. The TB germs can stay asleep for a long time, sometimes for life.
- It is not contagious, and you cannot spread TB infection to your family, friends, or others in the community.
- If you have TB infection, there is a risk of developing TB disease. If this happens, you will develop symptoms and may be able to spread TB germs to others.
What is TB disease?
- TB bacteria cause disease if the immune system can't stop them from growing. When TB bacteria grow in the body, it is called TB disease. People with TB disease are sick and may spread TB germs to family, friends, or within their community.
You are at higher risk of getting TB disease if:
- You have had TB infection in the last two to three years.
- You have lung scars that show on an x-ray.
- You are HIV positive or immune compromised.
- You consume more than three alcoholic drinks per day.
- You smoke at least one pack/day of tobacco cigarettes.
- You have diabetes, certain types of cancers, silicosis, or have had a transplant.
- You have stage four or five chronic kidney disease.
- You take certain medications (e.g., tumor necrosis factor or steroids).
What are the symptoms of TB disease?
- Coughing for longer than two weeks
- Coughing up blood or phlegm (sputum; thick liquid that comes up from your lungs/airways)
- Chest pain
- Fever/chills/night sweats
- Feeling tired
- Unexplained weight loss/loss of appetite
- Pain in other spots of the body where the TB bacteria are growing
If you develop any of these symptoms, seek immediate medical attention. Call ahead to let the healthcare provider or emergency department know that you may have TB disease. Ask for a mask when you arrive at the healthcare facility. Only a healthcare provider can tell you if you have TB disease.
What is the testing for TB infection?
- A tuberculin skin test (TST) or a blood test called Interferon Gamma Release Assay (IGRA) can be done to see if you have TB infection. During a TST, a tiny amount of inactive tuberculin is injected just under the skin on your forearm. The test must be read 48-72 hours later by a healthcare provider.
- A physical exam, chest x-ray, and testing of your sputum can be done to see if you have TB disease.
What is the treatment for TB infection?
- Your healthcare provider may recommend medication to kill the germs and prevent TB disease.
- The Health Unit will provide the medicine for free when we get your prescription. The length of time you take the medicine depends on what your healthcare provider prescribes; it could be anywhere between four to nine months. It is important to take all the medicine as prescribed. If you stop taking it too soon, you will not kill all the TB germs, and they may become stronger.
Where can I get more information about TB infection?
Contact the Communicable Disease Control (CDC) Program at 705-474-1400, or toll-free at 1-800-563-2808, ext. 5229 or email us at cdc@healthunit.ca.
Visit the Health Unit's webpage for more information on Tuberculosis.
References:
- Alvarez, G. G., Pease, C., and Menzies, D. (2022). Chapter 6: Tuberculosis preventive treatment in adults. Canadian Journal of Respiratory, Critical Care, and Sleep Medicine, 6 (sup1), 77-86.
- Campbell, J.R., Pease, C., Daley, P., Pai. M., and Menzies, D. (2022). Chapter 4: Diagnosis of tuberculosis infection. Canadian Journal of Respiratory, Critical Care, and Sleep Medicine, 6 (sup1), 49-65.
- Long, R., Divangahi, M., and Schwartzman, K. (2022). Chapter 2: Transmission and pathogenesis tuberculosis. Canadian Journal of Respiratory, Critical Care, and Sleep Medicine, 6 (sup1), 22-32.
- Public Health Agency of Canada (PHAC). (2024). Tuberculosis (TB): Prevention and Risks. Government of Canada.
- Public Health Agency of Canada (PHAC). (2024), Tuberculosis (TB): Symptoms and Treatment. Government of Canada.
Created: March 2026, by CDC