Not everyone who is exposed to and infected with TB bacteria becomes sick or progresses to having TB disease. There are two TB-related conditions known as latent TB infection (LTBI) and TB disease.
LTBI is the stage when the viable organism remains in the body, but the individual does not exhibit symptoms and is non-infectious to others. In most people who breathe in TB bacteria and become infected, the body is able to fight off the bacteria to stop them from multiplying. Common traits in people with LTBI:
- Have no symptoms
- Don’t feel sick
- Can’t spread TB bacteria to others
- Usually have a positive TB skin test reaction or positive TB blood test
- May develop TB disease if they do not receive treatment for latent TB infection
Many people who have LTBI never develop TB disease, and the TB bacteria can remain inactive for a lifetime without causing disease. But in other people, especially people who have a weak immune system, the bacteria can become active, multiply, and cause TB disease.
