IGRA is preferred for testing persons from groups that...

IGRA is preferred for testing persons from groups that historically have poor rates of return for TST reading
• IGRA is preferred for testing persons who have received BCG (as a vaccine or for cancer therapy)
• TST is preferred for testing children younger than 5 years of age
• IGRAs may be used in place of TST (without preference) to test recent contacts of persons with infectious tuberculosis with special considerations for follow-up testing
- Negative results prior to 8 wks typically should be confirmed by repeating the test 8–10 weeks after the end of exposure
- Repeating same test minimizes misclassification due to test discordance
• IGRAs may be used in place of TST (without preference) for periodic screening to address occupational exposure to TB with special considerations regarding conversions and reversions