Tuberculosis, also known as TB, is caused by bacteria that are spread from person to person through the air. TB usually affects the lungs but it can also affect other parts of the body, such as the bones, brain and kidneys. People who have TB disease spray bacteria into the air when they cough, laugh, sneeze, talk or sigh.
- You can get TB if you breathe in the bacteria and it settles in your lungs or other parts of your body.
- You must have close, long-lasting or frequent contact with someone who has TB disease to become infected.
- The bacteria that land on furniture, floors, tables or other surfaces cannot make you sick because the bacteria die quickly.
- A TB Skin Test or IGRA (Interferon Gamma Release Assay blood test) will let you know if you have TB infection in your body
- Watch TB personal stories
Latent TB Infection
- When TB bacteria are inside your body but they are not growing, you have Latent Tuberculosis Infection. Usually TB bacteria will stay inactive as long as your body’s immune system can fight them off.
- When you have Latent TB Infection, you do not feel sick and cannot spread the bacteria to make others sick.
- About 5 to 10% of people with Latent TB Infection develop TB disease in their lifetime.
- If your body’s immune system stops fighting the TB bacteria, they start to grow (bacteria increase in numbers). This is called TB disease; it can happen to anyone with Latent TB Infection at any time.
- Once the bacteria start to grow, they can damage the part of the body they have infected.
- The signs and symptoms of TB disease are:
- Coughing for more than three weeks
- Feeling weak and tired
- Loss of appetite and weight loss
- Sweating at night
- Coughing up fluid or blood
- Fever greater than 38.3 C measured orally
- Chest pain when you cough or breathe
Differences between Latent Tuberculosis Infection & Tuberculosis Disease
|A Person with Latent TB Infection||A Person with TB Disease|
What is a TB Skin Test?
A TB Skin Test can tell if you have TB bacteria in your body. This test cannot tell how long you have had the bacteria or if the TB bacteria is growing (TB disease) or not growing (Latent TB Infection). If you cannot have a TB Skin Test, your doctor may recommend a blood test (Interferon Gamma Release Assay - IGRA).
Steps for a TB Skin Test:
- A doctor or nurse injects a tiny amount of test fluid, called tuberculin, just under the skin of your forearm.
- You can return home. Do not touch or cover the spot where you had the injection, even if there is itching or redness.
- Return to the clinic 48 to 72 hours after you had your TB Skin Test. A doctor or nurse will measure the area. The TB Skin Test is usually positive if swelling the size of a dime or bigger develops at the area. A positive test does not mean you are sick with TB disease.
Where can I get a TB Skin Test in Hamilton?
Public Health Services provides free TB Skin Test only for people who have been named as a contact with a person who has TB disease.
TB Skin Test are available at:
- Your doctor’s office
- Walk-in clinics
- Employee health in your workplace
- The student health facility at your college or university
- Hamilton Family Health Team TB Skin Testing Clinic at 123 James St N Hamilton
TB Skin Tests are covered under the Ontario Health Insurance Plan (OHIP) for:
- People who are named as a contact of a TB case.
- People who need a TB Skin Test for medical reasons
- People who have recently immigrated from countries where TB is more common.
- People who require a TB Skin Test for admission to a daycare, pre-school program or a school, community college, university or other educational institution or program (including a work placement that the program may require)
- People who are 65 years of age or younger and need to be admitted to a Long Term Care Facility
- OHIP does not cover the cost of TB Skin Tests that are needed for employment or volunteer purposes.
What is an IGRA?
IGRA is a blood test called Interferon Gamma Release Assay that can be used to see if a person has the TB bacteria in their body. IGRA is not covered under the Ontario health insurance plan (OHIP).
I had a positive TB Skin Test / IGRA, what is the next step?
- A positive skin test / IGRA shows you have TB infection. More tests will be needed to make sure the TB bacteria is not growing. These tests usually include a check-up by a health care provider for signs and symptoms of TB disease and a chest x-ray
- Your doctor may recommend a sputum test to see if there are bacteria in your lungs or throat, if you have symptoms of TB disease or if your chest x-ray suggests you may have TB disease.
- Once your family doctor tells you that you do not have TB disease, ask about medication to prevent getting TB disease in the future. This medication is free of charge through Public Health Services.
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