Tuberculosis (TB)

Tuberculosis (TB) is an infectious illness caused by bacteria. It usually affects the lungs, but it can also affect other parts of the body. If not treated properly, TB disease can be fatal.

Not everyone infected with TB becomes sick. As a result, two TB related conditions exist: inactive TB infection and TB disease.

• In inactive TB infection, the TB bacteria live in the body without making you feel sick. The body is able to fight the bacteria to stop them from growing.
• If the bacteria become active and start growing, you will go from having TB infection to being sick with TB disease. People who have TB disease need medical care immediately as it is very severe and can cause death.

Some people are more at risk of getting TB disease, including:

• people who have had TB infection in the past 2 or 3 years
• people with lung scars that show on their chest X-rays
• people who are HIV-positive
• people with alcoholism
• people who inject illicit drugs
• people with diabetes and certain types of cancer
• people who are very thin or who don’t eat well
• people who frequently travel to countries where TB is common

Tuberculosis is a reportable disease in Ontario.

If you have inactive TB infection, you will not have any symptoms or feel sick.

If you have active TB disease, you may:

• cough a lot
• cough up mucus or blood
• have chest pain when you cough or breathe
• have a fever
• sweat at night
• lose your appetite
• lose weight
• feel weak
• have problems in the part of your body that has the TB disease

You should see a health care provider if you have symptoms of TB disease.

How do I know if I have a TB infection?

We offer TB skin tests at most of our offices, request an appointment. A public health nurse injects a serum under the surface of the skin on your arm which is then measured 2-3 days later. Swelling the size of a dime or bigger could indicate a positive result. A skin test is a sure way to find out if you’ve been exposed to tuberculosis.

If you have never received a TB skin test before, we recommend you repeat the skin test 1-3 weeks after getting your first test measured.

If your test is is positive, you will need to see a health care provider and have other tests performed, like a chest X-ray. These tests will determine if you have TB disease. If you are HIV-positive, your skin test could be negative even if the TB germs are in your body.

Tell your health care provider if you have ever had a positive reaction to a TB skin test before or if you have been treated with TB drugs.

How do I know if I have TB disease?

Only a health care provider can tell if you have TB disease. A chest X-ray will usually show if you have the disease in your lungs. Special tests on mucus (phlegm) that you cough up are also important.

TB disease spreads by tiny germs that can float in the air. The TB germs can spray into the air if a person with TB disease coughs, sings, or sneezes. The people nearby can breathe TB germs into their lungs and become infected.

People who have inactive TB infection cannot spread TB to other people.

TB infection

If you have TB infection, your health care provider might recommend medicine to keep you from getting TB disease and becoming sick. This is called preventive treatment.

TB medicine is free of charge. Your health care provider orders the drugs for you.

It takes many months of treatment to kill the TB germs. Unless you kill the TB germs with the right medicine, they will stay in your body and can cause TB disease later on. The usual length of treatment for TB infection is 9 months.

TB disease

TB disease can be cured but the TB germs are strong. To kill them you must take special medications for 6 to 12 months. You must take all the medication until your health care provider tells you to stop. If you stop taking the medication too soon, you will not be cured, you will feel sick again and you can continue to spread TB to others.

TB medicine is free of charge. Your health care provider orders the drugs for you.

Your health care provider will monitor your treatment closely and may make changes to your medications depending on how well the medications are working to kill the TB germs.

When you have active TB disease it is important that you stay away from people until your health care provider says you can no longer spread TB germs. This is usually after 2 or 3 weeks of treatment.

Simple preventative measures can reduce the spread of infection.

Long-term care and retirement homes outbreak management resources

Home Isolation Factsheet (PDF, 120 KB)