Incarceration as a predictor of latent TB infection among homeless people in Tarrant County, Texas

Background: Latent tuberculosis infection (LTBI), which affects an estimated 13.2 million people in the U.S., is a major impediment to TB elimination in the U.S. Testing and treatment of high-risk groups is a key focus of TB prevention efforts. Residence in shelters and correctional facilities are risk factors for LTBI, and both are more common among homeless people. We examined incarceration as a predictor of LTBI among homeless people in Tarrant County, Texas. Objective: To evaluate incarceration as a predictor of LTBI among homeless people in Tarrant County, Texas. Methods: We analyzed local data collected for the Tuberculosis Epidemiologic Studies Consortium, a 10-site study funded by the Centers for Disease Control and Prevention to assess sensitivity and specificity of three commercially-available tests for LTBI: the tuberculin skin test and two interferon-gamma release blood assays: QuantiFERON®-TB Gold In-Tube, and T-SPOT®.TB test. Analysis was confined to homeless persons who used night shelters in Tarrant County, enrolled from July 2012 to December 2016. LTBI was defined as a positive result from any test. Multiple logistic regression evaluated the relationship between LTBI and history of incarceration while controlling for drug or alcohol abuse, tobacco smoking, and other demographic and risk factors. Results: Among 1,030 shelter residents, history of incarceration was associated with increased likelihood of LTBI (adjusted odds ratio, 1.58; 95% confidence interval, 1.06 to 2.35). Conclusions: Among homeless shelter users in Tarrant County, Texas, LTBI was more common among those with a history of incarceration. This may be a useful indicator to prioritize LTBI screening.