QuantiFERON-TB Gold Versus Tuberculin Screening and Care Retention Among Persons Experiencing Homelessness: Georgia,...

Objectives. To characterize the cascade of care for latent tuberculosis infection (LTBI) in persons experiencing homelessness (PEH) and evaluate the effect of screening by QuantiFERON-TB Gold (QFT) versus tuberculin skin test (TST). Methods. We performed a retrospective cohort study of all PEH screened for LTBI by QFT and TST from May 2015 to April 2017 in Fulton County, Georgia. Results. There were 3504 PEH screened by QFT and 5509 by TST, with 2925 TSTs administered on site at community shelters and 2584 at the health department. More valid test results were obtained in those screened by QFT (99.0% vs 69.0%; P < .001) because of low return rates for reading in both TST arms. For tests administered on site, testing by QFT versus TST improved retention in care with significantly more estimated LTBI cases following up for a medical examination (67.8% vs 51.0%; P < .001) and starting LTBI treatment (58.4% vs 39.8%; P < .001). Conclusions. A QFT-based screening strategy in PEH improved diagnosis and retention in care for new LTBI cases compared with TST and may be an effective strategy to limit progression to active tuberculosis.