Tuberculosis (TB) remains a significant threat to humanity, and therefore identifying TB infection is essential. A person infected with Mycobacterium tuberculosis, but who shows no symptoms is regarded as having latent TB infection. Global organizations acknowledge that to fight TB effectively, accurate identification and treatment of latent TB infection, as well as active TB disease, are vital (9).
QuantiFERON-TB Gold (QFT) is a modern alternative to the 110 year old tuberculin skin test (or Mantoux test) and is the most studied IGRA, with over 800 published peer-reviewed publications. The test is highly accurate and unaffected by Bacillus Calmette-Guérin (BCG) vaccination (2–4).
QFT is an interferon-gamma (IFNγ) release assay, commonly known as an IGRA, and measures the cell-mediated immune response to specific TB antigens in whole blood. Patients may be tested in a single patient visit, with objective results, eliminating the need for two-step testing (1). The test has proven performance in immunosuppressed patients (5–8).
By reducing false positive results seen with TST, QFT reduces the costs associated with unnecessary chest X-rays, chemoprophylaxis, toxic side effects, lost productivity, and labor costs resulting from two-step TST testing. Studies show that QFT can reduce the cost of maintaining healthcare worker screening programs by up to 32% (10).