Not everyone infected with TB bacteria becomes sick. As a result, two TB-related conditions exist: latent TB infection (LTBI) and TB disease.
Latent tuberculosis infection (LTBI) is defined as a state of persistent bacterial viability, immune control, and no evidence of clinically manifested active tuberculosis.
There is no gold standard test for direct identification of Mycobacterium tuberculosis infection in humans. The vast majority of infected people with LTBI do not have signs and symptoms of TB disease, but are at risk for active TB disease.
While not everyone with LTBI will develop TB disease, about 5–10% of infected people will develop TB disease over their lifetimes if not treated for LTBI.
The only sign of TB infection is a positive reaction to the tuberculin skin test or TB blood test. Persons with latent TB infection are not infectious and cannot spread TB infection to others.
Latent tuberculosis infection
