What is latent tuberculosis infection (LTBI)?
Latent tuberculosis infection (LTBI) is when a person breathes in TB bacteria and becomes infected, but their body fights off the bacteria and keeps it from growing. The bacteria are not active inside the person’s body. However, they do remain alive in the body and can become active later on. People with LTBI have no symptoms, don’t feel sick and can’t spread TB to others. They usually, but not always, have a positive skin test or blood test reaction. They can develop active TB disease if they are not treated. Many people with LTBI never develop active TB disease. The TB bacteria remain inactive for life without causing disease. However, in other people, especially people who have weak immune systems, the bacteria can become active and cause TB disease. It is important to get treated for LTBI so that it doesn’t develop into active TB disease.
