Tuberculosis infection in an urban homeless population.

Abstract

People experiencing homelessness (PEH) are at increased risk of tuberculosis (TB) infection and progression to TB disease. Data on TB infection prevalence among hospitalised PEH in low-incidence countries remain limited. This study aimed to estimate TB infection prevalence and describe associated demographic and clinical characteristics among PEH admitted to an urban tertiary hospital in Dublin, Ireland. A prevalence study was conducted between November 2023 and March 2025 using an opt-out screening model. Hospitalised PEH were offered interferon gamma release assay (IGRA) testing on admission. Demographic and clinical data were collected, and positive IGRA results were assessed clinically and radiographically to exclude active TB disease. Estimated lifetime risk of progression to TB disease was calculated using a validated risk-modelling algorithm.Among 118 PEH screened, 13 (11%) were IGRA-positive and 3 (2.5%) had indeterminate results. The cohort was predominantly male (77%) with a mean age of 46 years. Non-Irish-born individuals had higher IGRA positivity than Irish-born participants (23.8% vs 8.3%, p = .054). Substance and alcohol use disorders were common, over half had previous incarceration, and one-third were sleeping rough at admission. Among IGRA-positive individuals, the mean estimated lifetime risk of progression to TB disease was 6.96% (SD 3.3). These findings support strengthened, integrated TB prevention strategies for PEH.