Tuberculosis (TB) Infection Screening or Confirmatory Test

What This Test Measures

TB tests typically involve checking for specific markers in your blood, urine, or other bodily fluids. Some tests detect antibodies produced by your immune system in response to TB exposure, while others identify direct evidence of the bacteria itself. Common methods include blood tests (like interferon-gamma release assays) or sputum cultures (for active infection).

Types of TB Tests

There are two main types of TB tests: screening tests (like the tuberculin skin test or blood tests) and confirmatory tests (such as PCR or culture tests). Screening tests are often used to identify exposure risk, while confirmatory tests confirm active infection or latent TB.

When You Might Need This Test

You may need a TB test if you have symptoms like persistent cough, fever, weight loss, or chest pain—especially if you live in an area with higher TB rates, have a weakened immune system, or have recently traveled to a region with active TB.

What to Expect Before the Test

For blood-based TB tests (e.g., IGRA), you may need to fast or avoid certain medications for a few hours before the procedure. For skin tests (like the Mantoux test), a small amount of fluid is injected under your skin, and you’ll return in 48–72 hours to check for a reaction.