Interferon-gamma release assays (IGRAs) are blood tests used to detect latent tuberculosis infection (LTBI). They measure the immune response to specific proteins associated with the Mycobacterium tuberculosis bacteria. Unlike traditional skin tests, IGRAs do not require a follow-up visit and are not affected by prior vaccination with BCG. These tests are particularly useful for individuals who may have difficulty with skin tests, such as those with weakened immune systems or those who have received the BCG vaccine. IGRAs provide results within 24 to 48 hours, helping healthcare providers make informed decisions about diagnosis and treatment.