Tuberculosis (TB) is estimated to infect a third of the world's population. Patients born, raised or recently arrived from high TB-burden countries, and patients from some indigenous communities, are at much higher risk of contracting TB. After infection, TB may remain latent for many years, re-emerging with immunosuppression or advancing age. Testing for TB varies according to the stage of the disease.
Latent TB infection is diagnosed by detecting specific immunological responses to Mycobacterium tuberculosis (MTB) proteins using interferon gamma release assays or tuberculin skin testing. For active TB, chest X-ray and microbiological tests are required. The development of interferon-gamma release assays (IGRAs) is an important advance in the diagnosis of latent tuberculosis infection (LTBI). IGRAs are in vitro blood tests of cell-mediated immune response; they measure T-cell release…
