What is Tuberculosis (TB)?
Tuberculosis (often called TB) is a bacterial infectious disease that usually attacks the lungs, but can attack almost any part of the body. TB can be an active disease (infectious) or latent infection (not infectious).
Latent Tuberculosis Infection
Latent TB, also known as “sleeping” TB (BC Centre for Disease Control, 2015), occurs when TB bacteria are breathed in, but the body is able to prevent the bacteria from growing. Although the bacteria may be sleeping now, they can become active later.
People with latent TB infection:
- Have no symptoms
- Don’t feel sick
- Can’t spread TB to others
- Usually have a positive skin test reaction
- Can develop active TB disease if they do not receive treatment for latent TB infection – especially people who have weak immune systems
Latent (Sleeping) Tuberculosis Video; gives a brief overview of TB, how it is spread, risk factors for being exposed to TB and the difference between latent TB infection and active TB disease.
What Do I Do If I Have Latent TB Infection?
Your doctor may recommend taking antibiotic treatment for 6–9 months to reduce the chances of TB infection progressing to TB disease. It is important to take all of your medication as prescribed by your doctor. TB drugs are provided free of charge from the Leeds, Grenville and Lanark District Health Unit.
TB Skin Test
The TB Skin Test (TST) shows if someone has been infected with the TB bacteria. You may need a TB Skin Test for employment, school, volunteering, travel, medical reasons or because you have been in contact with a person who has active TB.
A TB Skin Test involves injecting a small amount of testing material just below the top layers of skin, usually on the arm.
It may cause some swelling, itching or tenderness at the injection site. You can participate in normal activities following the test.
Two or three days later, a health care worker checks the arm to see if a bump has developed. The appearance and size of the bump determines the result of the test. If there is a bump, the health care worker will measure it and decide if the reaction is positive.
Sometimes the immune system of some individuals cannot ‘remember’ a past TB infection. These people may not have a reaction after the first TB Skin Test, but a second TB Skin Test may produce a positive response. This is called the ‘booster effect’.
A second TB skin test repeated 1–4 weeks after the first test is often required to get an accurate baseline for people who are going to be working or volunteering in a health care field.
A negative result means there is no reaction and that TB bacteria have not entered the body in the past.
It could also mean that the body has forgotten to react, such as when someone’s immune system is lowered due to medication, medical conditions or aging.
At some time in the past, TB bacteria have entered the body.
The health care provider will need to determine if the individual has inactive TB infection or active TB disease and will order a chest x-ray and possibly sputum tests (mucous/phlegm) if the person has symptoms.
Having a positive TB skin test does NOT mean that the infection can be passed to other people. The bacteria can only be transmitted if the person has signs of active TB disease such as coughing, night sweats, chills, weakness, weight loss and chest pain.
Medication may be prescribed which will slowly fight the TB bacteria and allow the body to heal. TB drugs are provided free of charge from the Health Unit.
Active TB Disease
Tuberculosis (TB) is a disease caused by bacteria called Mycobacterium tuberculosis. The bacteria usually attack the lungs; however TB bacteria can attack any part of the body. If not treated properly, TB disease can be fatal.
TB of the lungs is spread through the air from one person to another. The bacteria are released into the air when a person with active TB disease of the lungs coughs or sneezes. People nearby may breathe in these bacteria and become infected.
Who Should Be Tested for TB?
You should be tested for TB if you:
- Have immigrated from or spent time in a country where TB is common
- Have spent time with a person who has active TB disease
- Live in an aboriginal community where TB is common
- Work in a health care or live in a communal living setting (e.g., shelter, long-term care home, corrections facility)
- Are homeless or underhoused
- Use injection drugs
Home Isolation for Tuberculosis Disease
If you have TB disease in the lungs or throat, you can spread your TB through the air to other people when you cough, sneeze, talk, laugh or sing. It is important for you to stay at home in isolation. This will stop the spread of TB and protect your family and friends. You will be in isolation for a minimum of two weeks depending on how sick you are. You will need to stay at home in isolation until your Public Health Nurse tells you that you can no longer spread the disease to other people.