Around a quarter of the global population is estimated to be infected with the TB bacterium, with 5-10% of those developing active disease. Interferon Gamma Release Assays (IGRAs) are blood-based TB infection tests that measure the immune sensitization to mycobacterial protein antigens that occurs following infection by the TB bacterium. Unlike the tuberculin-based Mantoux skin test, IGRAs are not affected by prior BCG (bacille Calmette-Guérin) vaccination. Testing for TB infection before TB preventative therapy is particularly of use for people who are household contacts of people with TB or from other risk groups.

The introducing New Tools Project (iNTP) has provided QuantiFERON-TB Gold Plus (QFT-Plus) IGRA reagents to 3 countries for testing of 20,000 people for TB infection.


Countries that have implemented IGRAs under the project


Availability through Stop TB Partnership's GDF 

Reagents for IGRAs are available in the GDF Diagnostics, Medical Devices & Other Health Products Catalog and GDF Diagnostics, Medical Devices & Other Health Products Ordering List


Manual on the selection and use of IGRAs