Tuberculosis (TB) refers to an infection or disease caused by the tuberculosis bacteria.

What is TB infection?

TB infection is defined as a small number of TB bacteria living in your body but not causing illness. It occurs when TB bacteria are inhaled into the tiny air sacs of the lungs. A person with TB infection does not feel sick, has no symptoms, and cannot spread TB bacteria to others. If the body's immune system becomes weak, however, TB infection can develop into TB disease. Persons with TB infection are at risk of developing TB disease throughout their lifetime unless properly treated.

What is TB disease?

TB disease is defined as a large number of TB bacteria living in the body and causing sickness. TB disease usually affects the lungs, but can occur in any part of the body. The most common symptoms are weakness, weight loss, feeling sick, loss of appetite, fever, night sweats and cough. Persons with these symptoms should seek attention from a health professional who will order a chest x-ray and/or perform other clinical tests.

Is there a test to detect TB infection?

Yes. A tuberculin skin test detects TB infection and is available from your doctor, nurse, or health center. The skin test is determined to be positive when there is a significant amount of swelling at the skin test site 48 to 72 hours after the test is given.

How is TB infection treated?

Persons with TB infection can take anti-TB medication to prevent TB disease from occurring. Medicine is usually taken once daily for 6 to 12 months.

Can TB disease be treated?

Yes. Several anti-TB medications are taken for 6 to 12 months to cure TB disease.

Can TB bacteria be spread to others?

Yes. TB bacteria can be spread through the air to others who are living, working, or otherwise spending prolonged time with a person who is contagious (coughing or sneezing TB bacteria into the air). Many persons with TB disease are not contagious.

Can you get infected with TB from handling food?

No. TB bacteria are spread from person to person through the air only. TB infection cannot be acquired by handling food or objects.

What is drug resistant TB?

Drug resistant TB refers to TB disease caused by TB bacteria which is not killed (or cured) by standard drugs, making treatment more difficult. Persons with TB disease are at risk of developing drug resistant TB if medications are not taken according to directions for the full length of treatment.

What is BCG vaccine?

BCG is a vaccine for TB, and is the most common vaccine used in the world. Although it may cause a positive skin test reaction, BCG has not been shown to be completely effective and TB disease is common among BCG-vaccinated persons. Persons who have had BCG and have a positive skin test reaction should be evaluated for tuberculosis.