Yield, Efficiency, and Costs of Mass Screening Algorithms for Tuberculosis in Brazilian Prisons

Abstract

Background Tuberculosis is a major cause of morbidity and mortality among incarcerated populations globally. We performed mass tuberculosis screening in three prisons and assessed yield, efficiency, and costs associated with various screening algorithms. Methods Between 2017 and 2018, inmates from the three prisons in Brazil were screened for tuberculosis by symptom assessment, chest radiography, sputum testing by Xpert MTB/RIF 4th generation and culture. Chest radiographs were scored by an automated interpretation algorithm (CAD4TB) that was locally calibrated to establish a positivity threshold. Four diagnostic algorithms were evaluated. We assessed the yield (percent of total cases found) and efficiency (prevalence among those screened) for each algorithm. We performed unit costing to estimate the costs of each screening or diagnostic test and calculated the cost per case detected for each algorithm. Results We screened 5,387 prisoners, of whom 214 (3.9%) were diagnosed with tuberculosis. Compared to other screening strategies initiated with radiography or chest symptoms, the trial of all participants with a single Xpert MTB / RIF sputum test detected 74% of all tuberculosis cases at a cost of $ 249. Performing Xpert MTB/RIF screening tests only on those with symptoms had a similar cost per case diagnosed (US$ 255) but missed as many cases (73 vs 54) as screening all inmates. Conclusion In this prospective study in three with prisons in high tuberculosis burden countries Brazilian prisons, we found that testing all participants with sputum Xpert MTB/RIF was sensitive approach, while remaining cost-efficient. These results support use of Xpert MTB/RIF for mass screening in tuberculosis-endemic prisons.

Increased incarceration rates drive growing tuberculosis burden in prisons and jeopardize overall tuberculosis control in Paraguay

“…This is similar to results observed in Brazil over a similar period 9,[23][24][25] . Prison conditions in Brazil are likely to be similar to those in Paraguay, especially in the states or departments bordering the country 26 . Therefore, there is a need to work on joint transborder TB strategies for prisoners in Brazil and Paraguay 14 .…”

Blood-based host biomarker diagnostics in active case finding for pulmonary tuberculosis: a diagnostic case-control study

“…3 We tested two candidate triage diagnostics-point-of-care CRP and a new gene expression based rapid molecular diagnostic-from blood samples collected during systematic mass screening for TB conducted in two high TB-burden prisons, where we recently reported active TB prevalence of 3 900 per 100 000. 7 We found that both diagnostics had moderate accuracy in distinguishing microbiologically confirmed cases from controls, with Xpert-MTB-HR achieving higher overall accuracy than CRP. At 90% sensitivity, specificity of Xpert-MTB-HR was 53%, the latter falling below the target of 70%.…”

“…Second, control participants all had chest radiographs with CAD4TB scores <60 one year prior, but this may have led to selection of controls with less lung pathology, limiting generalizability. However, >80% of all individuals in the study prisons have CAD4TB scores <60, 7 suggesting that this group was still representative of the prison population. Third, because this was done within the context of an ongoing mass screening program, we used an older version of Xpert (G4) for the first part of the study and switched to the more sensitive Xpert Ultra when it became available at the site in January, 2020; because the Ct values are not comparable between the two cartridges, we only analyzed them for G4, which comprised 91% of the positive Xpert tests.…”

“…This nested diagnostic evaluation study was part of larger prospective mass TB screening study conducted in two prisons (Estabelecimento Penal Jair Ferreira de Carvalho [EPJFC] and Penitenciaria Estadual de Dourados [PED] in Mato Grosso do Sul, Brazil. 7 Between April 2018 and May 2020, we recruited all incarcerated individuals ages ≥18 years at both study prisons. After obtaining informed consent, we administered a standardized questionnaire to collect demographic and clinical information, including TB related symptoms as defined by WHO guidelines.…”

“…6 Recent studies in Brazil have demonstrated that the prevalence of active TB among incarcerated individuals exceeds 3 900 cases per 100 000 persons, among the highest reported in the world. 7 There is an urgent need for more effective strategies for early case detection among high TB burden populations.…”