What is TB?

TB is an infection caused by a bacteria, Mycobacterium tuberculosis. It can infect the lungs, bones, skin, and other body parts.

How is TB spread?

TB is spread when a person with active TB disease in the lungs coughs, talks, sings or breathes the germs out. If a susceptible person breathes in the bacteria they may become infected. Usually the only people infected by a person with active TB disease are those who are around that person for many hours.

What is Latent TB Infection?

For most people who breathe in TB bacteria, the body's immune system is able to fight the bacteria and stop them from growing. The bacteria become inactive, but remain alive in the body and could become active later. This is called TB infection.

Persons with TB infection:

• Have no symptoms
• Don't feel sick
• Can't spread TB to others
• Usually have a positive skin test reaction
• Can develop TB disease later in life if they do not receive preventive therapy or positive TB blood test.

What is Active TB Disease?

A person with latent TB infection develops Active TB Disease when their immune system can no longer contain the infection. Most often this infection settles in the lungs, but can present in other parts of the body. TB in the lungs may cause a bad cough that lasts longer than 3 weeks, coughing up blood or sputum, fever, night sweats, unexplained weight loss and/or excess fatigue. Only people who are sick with TB in the lungs can spread the infection to others. People with Active TB Disease will need to take specific medications to treat it. After treatment, they will no longer be infectious. 

1/6/2026