From the Research
The TB Gold test typically remains positive even after successful treatment for latent tuberculosis infection (LTBI). This test detects the immune response to TB antigens rather than the bacteria themselves, and this immunological memory often persists for years or even indefinitely after treatment 1, 2, 3, 4, 5. Therefore, the TB Gold test should not be used to monitor treatment effectiveness or to confirm cure of LTBI. Standard LTBI treatment regimens include isoniazid for 6-9 months, rifampin for 4 months, or isoniazid plus rifapentine weekly for 3 months (3HP regimen) 2, 3, 4, 5.
Key Points
- Treatment success is generally determined by completion of the prescribed medication course rather than by repeat testing.
- This persistence of test positivity occurs because the test measures T-cell memory to TB antigens, which remains even after the infection is controlled.
- For this reason, healthcare providers should document a person's positive TB Gold test result and avoid repeating the test after treatment, as it provides no useful clinical information about treatment success.
Treatment Regimens
- Isoniazid for 6-9 months
- Rifampin for 4 months
- Isoniazid plus rifapentine weekly for 3 months (3HP regimen)
Important Considerations
- The TB Gold test is not a useful tool for monitoring treatment effectiveness or confirming cure of LTBI.
- Healthcare providers should focus on completing the prescribed treatment course rather than relying on repeat testing.
- Documenting a person's positive TB Gold test result is essential to avoid unnecessary repeat testing.