TB Infection

• TB Infection (or previously known as Latent TB infection) is a stage in between uninfected and having active TB. In this stage the person has no symptoms and can only be identified using laboratory tests.

• The vast majority of infected people may never develop TB disease. However, to achieve TB elimination, it is important to treat TB infection in people at risk of developing active TB disease.

• It is a state of persistent immune response to stimulation by Mycobacterium tuberculosis antigens with no evidence of clinically manifested active TB.

• There is no single acceptable/reliable test for direct identification of Mycobacterium tuberculosis infection in humans. Tuberculin Skin Test (TST) and Interferon-gamma release assay (IGRA) are commonly used tests for identifying TB infection.

Resources:

• Latent Tuberculosis Infection Guideline

• Guideline for Programmatic Management of Tuberculosis Preventive Treatment in India