Interferon-γ Release Assays for Tuberculosis Infection Diagnosis in Refugees <5 Years Old

Background New guidelines support using interferon-γ release assays (IGRAs) in children ≥2 years for diagnosis of latent tuberculosis infection (LTBI). However, lack of experience in young children and concern that IGRAs are less sensitive than tuberculin skin tests (TSTs) limit their use. Our aim was to identify active tuberculosis (TB) cases among high risk children Methods . Retrospective review of domestic TB screening data from California's Refugee Health Electronic Information System for children Results A total of 3371 children 150 cases per 100 000). Half received IGRAs (n = 1878; 56%), a quarter received TSTs (n = 811; 24%); 1.4% of children were IGRA-positive (n = 26) and 13% were TST-positive (n = 106). Twenty-two IGRA results were indeterminate (1.2%). Sixteen children had both tests; 9 were discrepant (positive TST with negative IGRA). No cases of TB disease were identified during 10 797 person-years of follow-up. Conclusions IGRA positivity was less than TST positivity in high risk children <5 years old. Despite fewer LTBI diagnoses in the IGRA-tested population, no cases of TB disease among children who tested negative were identified, suggesting IGRA is valuable tool for identifying LTBI in this population.