Impact of Routine Quantiferon Testing on Latent Tuberculosis Diagnosis and Treatment in Refugees in Multnomah County, Oregon, November 2009–October 2012

Interferon-gamma release assays have potentially been transformative to screening programs focused on latent tuberculosis infection (LTBI) in foreign-born persons. We sought to add to this assessment by presenting the impact of a well-established refugee screening and treatment program switching from skin testing to Quantiferon^®-TB Gold (QFT). We completed a retrospective cohort of refugees screened for tuberculosis between November 1, 2009–April 30, 2011 (pre-QFT) and May 1, 2011–October 31, 2012 (post-QFT). Among 2244 refugees screened that met the inclusion criteria, there was a significant difference in the proportion of refugees diagnosed with LTBI between the two time periods (p = <0.0001). In multivariate analysis, refugees tested with QFT had a greater odds of treatment initiation (adjusted odds ratio 1.53; 95 % CI 1.02–2.29, p = 0.040). However, test type had no impact on treatment completion (odds ratio 0.88; 95 % CI 0.57–1.36, p = 0.560). Although we demonstrated increased efficiency in LTBI diagnosis in this group, treatment completion rates indicate other barriers to treatment that must be addressed.