Interferon-Gamma Release Assays (IGRAs) - Blood Tests for TB Infection

This information sheet discusses interferon-gamma release assays (IGRAs), which are whole-blood tests used in diagnosing both latent TB infection and TB disease. It notes that two IGRAs have been approved by the US Food and Drug Administration (FDA) and are commercially available in the United States. The information sheet explains how the IGRAs work; the advantages, disadvantages, and limitations of IGRAs; steps in administering these tests; interpretation; recommendations on when to use them; and whether IGRAs can be given to persons receiving vaccinations.