The QuantiFERON TB test, also known as a TB blood test, is a blood test that checks for prior exposure to tuberculosis.

This test is a blood-based interferon-gamma release assay (IGRA) used as an aid in the diagnosis of Mycobacterium tuberculosis infection. It is an immune response-based, indirect test for M tuberculosis infection (including disease) and is intended for use in conjunction with risk assessment, radiography, and other medical and diagnostic evaluations. Additional testing is needed to determine if a person who has tested positive has latent tuberculosis (TB) infection or TB disease.

Guidelines recommend testing for individuals who:

1) have been exposed to a person with latent or active TB, including the general population and healthcare workers;

2) are from TB-endemic countries, which include most countries in Latin America, the Caribbean, Africa, Asia, and Eastern Europe, and Russia;

3) work in high-risk settings, such as correctional facilities, long-term care (LTC) facilities, nursing homes, and homeless shelters; or

4) have HIV or have an injection drug substance use disorder .