Which test is used for the identification of Mycobacterium tuberculosis?

The QuantiFERON-TB Gold test is a specific diagnostic tool designed for the identification of Mycobacterium tuberculosis, the bacteria that causes tuberculosis (TB). This test is a type of interferon-gamma release assay (IGRA) that measures the immune response to specific TB antigens. When a person has been exposed to the bacteria, their immune system will produce interferon-gamma in response to these antigens, indicating a TB infection.

This test is particularly advantageous because it can be performed regardless of a prior history of BCG vaccination and does not require the patient to return for a reading like the tuberculin skin test does. It also provides more reliable results in individuals who may have a weakened immune response, which is essential for accurate diagnosis.

In contrast, blood cultures are typically used for detecting active infections caused by a variety of pathogens, including bacteria and fungi, but are not specific for Mycobacterium tuberculosis. The tuberculin skin test, while a common screening tool for TB, is less specific and can yield false positives in individuals with prior BCG vaccination or who have been exposed to non-tuberculous mycobacteria. Biochemical tests are more general and not specifically targeted toward identifying Mycobacter