Undiagnosed Pulmonary Tuberculosis Among Incarcerated Individuals and Its Overlooked Transmission Risk for the Community in Central Ethiopia

<b>Background:</b> Tuberculosis (TB) remains a major public health problem globally, particularly in resource-limited settings where deprived ventilation, overcrowding, and limited healthcare services. Incarcerated individuals are among vulnerable populations disproportionately affected by TB due to confined living conditions and delayed diagnosis. In Ethiopia, the prison setting provides an environment favorable to the rapid spread of TB and a threat to the outside community. Thus, this study aims to determine the prevalence of undiagnosed pulmonary tuberculosis (PTB) and its predictors among incarcerated individuals in Central Ethiopia. <b>Methods:</b> A facility-based cross-sectional study was conducted from September to December 2023 among 363 selected incarcerated individuals in Central Ethiopia. Sociodemographic, clinical, and other risk-related data were collected using a structured questionnaire. Sputum samples were collected from incarcerated individuals with clinical symptoms of cough for two or more weeks and processed using GeneXpert MTB/RIF. The study was not formally powered to detect specific odds ratios for risk factor analysis; therefore, the associated predictors were explored through multivariable analysis and interpreted cautiously. <b>Results:</b> In 3802 total incarcerated individuals in the region's prisons, 363 (9.5%) with clinical symptoms and 13 (0.34%) already on anti-TB treatment were identified. Among these 363 (9.5%) with clinical symptoms, 35 (9.64%) previously undiagnosed PTB cases were detected. Hence, the point prevalence of undiagnosed PTB among incarcerated individuals was 0.92% or 920 per 100,000 population (95% CI: 830-998/100,000), which is about 7.7 times higher than Ethiopia's general population (119/100,000). This previously undiagnosed PTB was associated with incarcerated individuals who had smoking, increased age, contact with coughing/TB patients, chronic illness comorbidity, overcrowding, and low BMI. <b>Conclusion:</b> This study revealed a high point prevalence of undiagnosed PTB among incarcerated individuals. This mightily highlights that prisons are explicitly taken as a risky place for the transmission of PTB. Routine TB screening during prison entrance and periodical active case finding are highly recommended to identify missing people with TB who have a high spreading. After diagnosis, early treatment must be implemented to limit further transmission to incarcerated individuals and the surrounding community.