In most people who breathe in TB bacteria and become infected,
the body is able to fight the bacteria to stop them from growing.
The bacteria become inactive, but they remain alive in the body
and can become active later. This is called Latent TB Infection
or LTBI for short. People with LTBI:
* 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
treatment for LTBI
Many people who have LTBI never develop TB disease. In these
people, the TB bacteria remain inactive for a lifetime without
causing disease. But in other people, especially people who have
weak immune systems, the bacteria become active and cause TB disease.