Mass TB screening in a Brazilian prison: prevalence and implications for control
E.G. Boeira, J.V. Bortolotto Bampi, M.M. Dall’ Soto, L. Maia de Oliveira, T.A. Heringer, D.K. Back, P. Schwarzbold, N.D. Bierhals, D.H. Tsuha, N.Q. Félix, M. Sackser, M.E. Souza, P.D. Santos Huff, C. Busatto, J. Croda, J. Andrews, I.B. Ramis, A. Rosane de Moura Valim, M. Carneiro, L. Possuelo<sec><title>BACKGROUND</title>TB remains a major public health challenge in prisons due to overcrowding and limited health care access. Evidence on integrated mass screening strategies using molecular testing and computer-aided detection (CAD) in Brazilian prisons is scarce.</sec><sec><title>METHODS</title>A cross-sectional mass screening study was conducted in a male prison in southern Brazil. Screening included symptom assessment, digital chest X-ray with automated interpretation (LunitTB), and GeneXpert MTB/RIF testing. TB infection (TBI) was assessed using interferon-gamma release assay (IGRA). Socio-demographic, clinical, and behavioural data were analysed to identify factors associated with TB.</sec><sec><title>RESULTS</title>A total of 652 (96.3%) of 677 individuals completed screening; 120 (18.4%) underwent IGRA testing. Active TB prevalence was 4.7% (31 cases). TB was associated with contact with a TB case within the same cell, alcohol use disorder, weight loss, chest pain, and night sweats. Among 117 individuals tested, 62% were TBI-positive. The CAD system showed strong performance (area under the curve: 0.90; optimal threshold: 43.5).</sec><sec><title>CONCLUSION</title>Systematic screening revealed a high burden of TB and TBI in this setting. Chest X-ray combined with CAD was effective, identifying cases likely missed by symptom-based screening alone.</sec>