A Pilot TB Screening Model in a U.S. Prison Population Using Tuberculin Skin Test and Interferon Gamma Release Assay Based on Country of Origin.

The objective of this study was to compare tuberculosis (TB) screening results before and after implementation of a stratified testing strategy screening pilot study, incorporating interferon gamma release assay (IGRA) and tuberculin skin test (TST), based on country of origin. In 2015, the Washington State Department of Corrections began screening people born outside of the United States for TB with IGRA, while U.S.-born people continued screening by TST. Of 405 (75%) foreign-born men screened with IGRA, 403 had valid test results and IGRA screening positivity was 10.4% (N = 42). In contrast, among 5,940 primarily U.S-born men screened with TST, 24 (0.4%) were positive. Overall positivity was 1.05%, similar to TST-only positivity in 2013 (1.05%) and 2014 (0.85%). Incorporating IGRA screening among foreign-born persons was feasible in this state prison system.