Tuberculin skin test versus interferon-gamma release assay in refugee children: A retrospective cohort study.

Aim: The aim of this study was to assist clinicians evaluating refugee children for latent tuberculosis infection (LTBI) by comparing paired tuberculin skin test (TST) and Quantiferon Gold In-Tube (QGIT) test results with clinical management decisions and follow-up data in a large cohort of newly arrived refugee children.

Methods: This was a retrospective analysis of all refugee children (<15 years of age) evaluated for LTBI with both TST and interferon-γ release assay between 2007 and 2010 in the Illawarra-Shoalhaven region of New South Wales, Australia. Demographics, country of origin, bacille Calmette-Guerin (BCG) vaccination status, chest X-ray results, TST and QGIT test results, clinical management and outcome on long-term follow-up were assessed.

Results: Of 272 children evaluated, complete results were available for 212 (78%). The vast majority (207; 98%) were from Africa or Southeast Asia. Overall, 33 (16%) children were treated for LTBI; 13 (39%) had concordant TST and QGIT results and 20 (61%) discordant results. Of 63 (30%) TST-positive (≥10 mm) children, 46 (73%) were QGIT assay-negative, 44 (70%) had a BCG scar, 3 (5%) were younger than 2 years and 6 (10%) were treated for LTBI. Of 32 QGIT assay-positive children, 15 (47%) were TST negative, 31 (97%) had a BCG scar, all were older than 2 years and 14 (44%) were treated for LTBI.

Conclusions: Discordant TST and QGIT results were found in a high percentage of refugee children. QGIT is convenient and more specific than TST to diagnose LTBI in BCG-vaccinated children, although a careful tuberculosis exposure history and clinical assessment to rule out active disease remain important.