Tuberculosis (TB) is a disease caused by a bacteria called mycobacterium tuberculosis. Tuberculosis usually affects the lungs first, but it can also affect other parts of the body such as bones, joints, lymph nodes, brain, gut, and urinary system. TB is preventable, treatable, and curable.
TB is spread from person to person through the air. It is spread through close, prolonged, or regular contact with someone who is sick with TB in the lungs or throat, when they cough or sneeze.
The TB skin test (TST) is used to check for exposure to the TB bacteria at some time in an individual's life. A positive skin test indicates exposure to the bacteria, but does not indicate a person has TB. You cannot get TB from having the skin test done.
Most people who breathe in TB bacteria are able to stop them from growing. The immune system traps the TB bacteria and keeps them inactive. This is called latent TB infection. These people are well, have no symptoms and cannot spread TB bacteria, but will have a positive skin test. Over a life-time, only about 10 percent of healthy people with a positive skin test will develop TB disease. These people can take preventive medicine to reduce their chances of developing TB disease later in life, by as much as 90 percent.
TB bacteria become active when the body's immune system is no longer able to contain the infection and stop the bacteria from growing. Symptoms of TB disease in the lungs are:
If the TB disease is in another part of the body, the symptoms will depend on where the TB is growing, for example, a swollen lymph node or joint pain.
Note: Only a person with TB disease in the respiratory tract (i.e., lungs and throat) may be considered infectious to others.
Groups of people that are at a higher risk of developing TB disease include people with:
The following groups of people are considered to be at a higher risk of being exposed to TB disease:
People with TB infection may benefit from medicine to prevent TB disease. People with TB disease must complete treatment to cure the disease. TB drugs are provided free of charge by KFL&A Public Health, when ordered by a doctor.
TB disease is different in children than in adults. Although the disease can still occur in the lungs or other parts of the body, children often have fewer symptoms and will, more frequently, develop the disease in their lymph nodes.
If you have had a lot of contact with someone who has infectious TB disease, you will need to have one or two TB skin tests. If you have been exposed to someone with TB disease, contact KFL&A Public Health.
For more information, contact KFL&A Public Health at 613-549-1232 or 1-800-267-7875, ext. 1287 or visit www.kflapublichealth.ca.
Revised: 2011-02-28