Glossary | Overview
- Active TB disease: An illness in which TB bacteria are multiplying and attacking different parts of the body. The symptoms of active TB disease include cough, weakness, weight loss, fever, no appetite, chills, and sweating at night. A person with active TB disease may be infectious and spread TB to others.
- BCG: A vaccine for TB. BCG is not widely used in the United States, but it is often given to infants and small children in other countries where TB is common.
- Chest x-ray: A picture of the inside of your chest. A doctor can look at a chest x-ray to see whether TB bacteria damaged your lungs.
- Contact: A person who has spent time with a person with infectious TB.
- Culture: A test to see whether there are TB bacteria in your phlegm or other body fluids.
- Directly observed therapy (DOT): A way of helping patients take their medicine for TB. If you get DOT, a health care worker meets with you every day or several times a week to make sure you are taking your medicine.
- Extrapulmonary TB: Active TB disease in any part of the body other than the lungs (for example: the kidney, spine, brain, or lymph nodes).
- HIV infection: Infection with the human immunodeficiency virus (HIV), the virus that causes AIDS (acquired immunodeficiency syndrome). A person with both latent TB infection and HIV infection is at very high risk for active TB disease.
- INH or isoniazid: A medicine used to prevent active TB disease in people who have latent TB infection. INH is also one of the four medicines often used to treat active TB disease.
- Latent TB infection: A condition in which TB bacteria are alive but inactive in the body. People with latent TB infection have no symptoms, don't feel sick, can't spread TB to others, and usually have a positive skin test reaction. But they may develop active TB disease if they do not receive treatment for latent TB infection.
- Multidrug-resistant TB (MDR TB): Active TB disease caused by bacteria resistant to two or more of the most important medicines: INH and RIF.
- Mycobacterium tuberculosis: Bacteria that cause latent TB infection and active TB disease.
- Negative: Usually refers to a test result. If you have a negative TB skin test reaction, you probably do not have TB infection.
- Positive: Usually refers to a test result. If you have a positive TB skin test reaction, you probably have TB infection.
- Pulmonary TB: Active TB disease that occurs in the lungs, usually producing a cough and fever that lasts three weeks or longer. Most active TB disease is pulmonary.
- QuantiFERON-TB? Gold (QFT): A blood test used to find out if you are infected with TB bacteria. The QFT measures the response to TB proteins when they are mixed with a small amount of blood.
- Resistant bacteria: Bacteria that can no longer be killed by a certain medicine.
- Smear: A test to see whether there are TB bacteria in your phlegm.
- Sputum: Phlegm coughed up from deep inside the lungs. Sputum may be examined for TB bacteria.
- TB skin test: A test that is often used to detect latent TB infection.
- Tuberculin or PPD: A liquid that is injected under the skin on the lower part of your arm during a TB skin test. If you have latent TB infection, you will probably have a positive reaction to the tuberculin.