Serial Mass Screening for Tuberculosis among Incarcerated Persons in Brazil.

BACKGROUND:Active search for tuberculosis cases through mass screening is widely described as a tool to improve case detection in hyperendemic settings. However, its effectiveness in high-risk populations, such as incarcerated people, is debated. METHODS:Between 2017 and 2021, three rounds of mass screening were carried out in three Brazilian prisons. Social and health questionnaires, chest X-rays and Xpert MTB/RIF were performed. RESULTS:Over 80% of the prison population was screened. Overall, 684 cases of pulmonary tuberculosis were diagnosed. Prevalence across screening rounds was not statistically different. Among incarcerated persons with symptoms, the overall prevalence of tuberculosis per 100,000 persons was 8,497 (95% CI, 7,346-9,811), 11,115 (95% CI, 9,471-13,082), and 7,957 (95% CI, 6,380-9,882) in screening rounds one, two and three, respectively. Similar to our overall results, there were no statistical differences between screening rounds and within individual prisons. We found no statistical differences in CAD4TB scores across screening rounds among people with tuberculosis - the median scores in rounds 1, 2, and 3 were 82 (IQR, 63-97), 77 (IQR, 60-94), and 81 (IQR, 67-92), respectively. CONCLUSIONS:In this environment with hyperendemic rates of tuberculosis, three rounds of mass screening did not reduce the overall tuberculosis burden. In prisons, where a substantial amount of TB is undiagnosed annually, a range of complementary interventions and more frequent TB screening may be required.