Background Tuberculosis incidence is increasing in Latin America, where the incarcerated population has nearly quadrupled since 1990. The full impact of incarceration on the tuberculosis epidemic, accounting for effects beyond prisons, has never been quantified.

Methods We calibrated dynamic compartmental transmission models to historical and contemporary data on incarceration and tuberculosis in Argentina, Brazil, Colombia, El Salvador, Mexico, and Peru. Together these countries comprise approximately 80% of the region’s incarcerated population and tuberculosis burden. Using historical counterfactual scenarios, we estimated the transmission population attributable fraction (tPAF) for incarceration and the excess population-level burden attributable to increasing incarceration prevalence since 1990. We additionally projected the impact of various incarceration scenarios on future population tuberculosis incidence.

Findings The rise in incarceration prevalence since 1990 has resulted in an estimated 30,241 (95% UI, 24,333 - 39,303) excess incident tuberculosis cases in 2019 across the six countries. The tPAF for incarceration in 2019 was 23.5% (95% UI, 17.7-32.0), exceeding estimates for other key risk factors like HIV, alcohol use disorders, and undernutrition. Compared to a base-case scenario where current incarceration policies persist, decarceration interventions could reduce future population tuberculosis incidence in all countries, notably by over 10% in Brazil, Colombia, El Salvador, and Peru.

Interpretation The historical rise in incarceration in Latin America has resulted in a large excess burden of tuberculosis that has been under-recognized to-date. International health agencies, ministries of justice, and national tuberculosis programs should collaborate to address this health crisis with comprehensive strategies, including decarceration.

Funding National Institutes of Health

Evidence before this study We searched PubMed for studies on tuberculosis in prisons in Latin America, using the search terms (“tuberculosis”) AND (“prisons” OR “incarceration”) AND (“Latin America” OR “Argentina” OR “Brazil” OR “Colombia” OR “El Salvador” OR “Mexico” OR “Peru”), published in any language. Previous studies have identified a high risk of tuberculosis in prisons in Latin America, finding that notifications in prisons are increasing and account for a growing proportion of all cases in the region. Other national or sub-national studies have found elevated tuberculosis risk among formerly incarcerated individuals and transmission chains spanning prisons and communities. However, the full contribution of incarceration to the broader tuberculosis epidemic in Latin America—accounting for historical incarceration trends, under-detection in prisons, and “spillover” effects into communities—has never been quantified. Furthermore, previous studies have evaluated biomedical interventions in prisons; the regional impact of alternative incarceration policies on future population tuberculosis incidence is unknown.

Added value of this study Here we quantify the full contribution of incarceration to the tuberculosis epidemic in Latin America. Our model captures the dynamic nature of incarceration, incorporating historical and contemporary data sources to account for varying prison turnover rates and mechanisms underlying historical incarceration growth. By modeling the population with incarceration history, we estimate the true size of the ever-exposed population, which across the six countries is nearly 14 times the size of the population within prison at any one time. We identify the settings where excess cases occur and compare our results to crude estimates based on notifications in prisons. We show, across six countries with diverse carceral contexts and tuberculosis epidemiology, that incarceration is a leading driver on par with other major tuberculosis risk factors, a role that has been under-recognized to date. Finally, we demonstrate the potential impact of alternative incarceration policies in reducing future tuberculosis burden in carceral settings and the general population.

Implications of all the available evidence To date the true impact of incarceration on the tuberculosis epidemic across the region has been underestimated due to a narrow focus on disease occurring during incarceration. In light of the substantial excess tuberculosis burden attributable to incarceration, interventions targeting incarceration can have outsized effects on the broader tuberculosis epidemic in Latin America— much greater than previously appreciated. These interventions should include not only strategies to reduce tuberculosis risk among currently and formerly incarcerated individuals, but also efforts to end mass incarceration.

The authors have declared no competing interest.

This study was funded by the National Institutes of Health (grant numbers 5R01AI130058 and 5R01AI149620).

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All data produced in the present study are available upon reasonable request to the authors and will be made available upon publication