The QuantiFERON(R) TB Gold (in Tube) assay is intended for use as an aid in diagnosis of TB infection. Negative results suggest that there is not TB infection. In patients with high suspicion of exposure, a negative test should be repeated. A positive test indicates infection with Mycobacterium tuberculosis.

A “positive” TB blood test result means you probably have TB germs in your body. Most people with a positive TB blood test have latent TB infection. To be sure, your doctor will examine you and do a chest x-ray. You may need other tests to see if you have latent TB infection or active TB disease

Yes, this is true. Even after you finish taking all of your TB medicine, your TB skin test or TB blood test will still be positive. Ask your healthcare provider to give you a written record that says your test was positive and that you finished treatment.

IGRAs– Blood Tests for TB Infection Fact Sheet