Approach to diagnosis of latent tuberculosis infection (tuberculosis screening) in HIV-uninfected children

LTBI: latent tuberculosis infection; TB: tuberculosis; IGRA: interferon-gamma release assay; TST: tuberculin skin test; BCG: Bacille Calmette-Guérin; AFB: acid-fast bacilli.
* For indications for LTBI testing, refer to the UpToDate topic on diagnosis of LTBI. Only those who would benefit from treatment of LTBI should undergo testing, so a decision to test presupposes a decision to treat if the test is positive.
¶ Refer to the UpToDate topic on LTBI in children for definitions of positive TST results.
Δ IGRA is preferable over TST if available, particularly if the child has received BCG vaccine and/or is unlikely to return to have the TST read.
◊ Evaluation for active TB includes clinical history, physical examination, chest radiograph, and respiratory samples for AFB smear and TB culture; refer to the UpToDate text for further discussion.
§ For case contacts <5 years of age, we recommend initiating treatment for LTBI even if the initial TST or IGRA is negative.
¥ BCG vaccine administration can confound TST interpretation.