Approach to diagnosis of tuberculosis infection (tuberculosis screening) in children

AFB: acid-fast bacilli; BCG: Bacille Calmette-Guérin; IGRA: interferon-gamma release assay; TB: tuberculosis; TST: tuberculin skin test.

* For indications for TB infection testing, refer to the UpToDate topic on diagnosis of TB infection. TB screening is reserved for individuals who are at increased risk of developing TB disease and would thus benefit from treatment.

¶ Children residing in high TB incidence settings should be evaluated in accordance with national guidance, usually if living with HIV infection and/or when identified as a contact of a person with TB disease.

Δ Either IGRA or TST may be used for children of any age; refer to text for comparison of IGRA and TST. IGRA is preferred over TST for children who have received BCG vaccine and for children who are unlikely to return for TST reading.

◊ Refer to the UpToDate topic on TB infection in children for definitions of positive TST results.

§ TB infection is less likely in those with a negative screening test than in those with a positive test; however, false-negative results can occur - particularly in children who are recent contacts of a person with TB disease and/or children who are living with HIV infection. Further evaluation and management of patients with negative screening test results are discussed separately.

¥ BCG vaccine administration can confound TST interpretation.

‡ Evaluation for TB disease includes clinical history, physical examination, chest radiograph, and respiratory samples for AFB smear, TB culture, and nucleic acid amplification testing; refer to the UpToDate text for further discussion.