Tuberculosis Infection in an Urban Homeless Population

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 are limited.This study aimed to estimate the prevalence of TB infection and describe associated demographic and clinical characteristics among PEH admitted to an urban tertiary hospital in Dublin, Ireland.A prevalence study was conducted from November 2023 to March 2025 using an opt-out screening model.Hospitalised PEH were offered interferon gamma release assay (IGRA) testing at admission.Demographic and clinical data were collected, and positive IGRA results were assessed to exclude TB disease based on clinical evaluation and radiography.Estimated lifetime risk of progression to TB disease was calculated for IGRA-positive individuals using a validated risk-modelling algorithm.Statistical analyses included Fisher's exact test and ttests where appropriate.Of 118 PEH screened, 13 (11%) tested 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 a higher proportion of IGRA positivity compared with Irish-born participants (23.8% vs. 8.3%, p = 0.054).Substance and alcohol use disorders were common, over half had been incarcerated 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).TB infection prevalence among hospitalised PEH in Dublin was notably higher than national estimates for the general population, underscoring the vulnerability of this group.While non-Irish birth appeared to increase infection likelihood, homelessness itself remains an important risk factor.Opt-out inpatient screening may support earlier identification of TB infection in