🟢 Strong Evidence
Comprehensive tuberculosis screening in prisons using chest X-ray technology could reduce population-wide TB incidence by up to 28% while proving cost-effective across Latin American countries, according to new mathematical modeling published in PLOS Medicine. The study by Liu et al. analyzed screening strategies across Brazil, Colombia, and Peru, where incarceration drives tuberculosis transmission beyond prison walls.
Key takeaways
- Combined entry, exit, and twice-yearly screening with chest X-ray technology reduced TB incidence by 61%-87% in prisons and 18%-28% population-wide
- The comprehensive screening strategy cost $176-$434 per disability-adjusted life year averted across the three countries
- Screening at entry and exit alone provided 85%-94% of the benefits at 43%-67% of the cost compared to adding regular prison-wide screening
Study at a Glance
| Source | PLOS Medicine |
| Study type | Mathematical modeling study |
| Population | Prison populations and general communities |
| Countries | Brazil, Colombia, and Peru |
| Time horizon | 2026-2035 |
Prison TB screening effectiveness varies by strategy and country
Population-wide tuberculosis incidence reduction by 2035, percent
Source: Liu et al., PLOS Medicine 2024 | Georgian Medical Journal News
Comprehensive screening strategy shows strongest impact
The research team, led by Yiran E. Liu and colleagues, used dynamic transmission models to evaluate four screening algorithms across different implementation schedules. The most effective approach combined entry screening, exit screening, and twice-yearly prison-wide screening using chest X-ray with computer-aided detection (CXR-CAD), according to the PLOS Medicine study.
This comprehensive strategy reduced within-prison TB incidence by 61% in Brazil, 73% in Colombia, and 87% in Peru by 2035, according to the Liu et al. study. The population-wide benefits were substantial, with reductions of 18%, 23%, and 28% respectively in the three countries.
Entry and exit screening provides most cost-effective approach
While comprehensive screening showed the greatest health impact, screening only at prison entry and exit emerged as the most cost-effective strategy. This approach delivered 85%-94% of the health benefits at 43%-67% of the total cost, according to the economic analysis by Liu et al.
The cost per disability-adjusted life year (DALY) averted ranged from $80-$140 for entry/exit screening compared to $176-$434 for the comprehensive approach, according to the study. For readers interested in broader health policy implications, these findings suggest that even modest screening interventions could yield substantial population health returns.
Combined entry, exit, and biannual screening with CXR-CAD was highly impactful and cost-effective across countries, reducing tuberculosis incidence by 61%–87% in prisons and 18%–28% population-wide
— Liu et al., PLOS Medicine, 2024
Technology choice affects screening effectiveness
The study compared four screening algorithms, with chest X-ray technology outperforming symptom-based approaches. CXR-CAD detected tuberculosis cases that symptom screening missed, while pooled sputum testing with GeneXpert Ultra showed promise but faced implementation challenges, according to the Liu et al. findings.
Symptom screening alone proved least effective, missing asymptomatic cases that drive transmission within facilities, the study found. These technological considerations align with recent advances in clinical updates showing improved tuberculosis diagnostic capabilities in resource-limited settings.
Regional variations highlight implementation considerations
The three countries showed different baseline tuberculosis burdens and screening effectiveness, reflecting diverse epidemiological contexts. Peru demonstrated the highest potential for population-wide impact, while Brazil showed more modest but still substantial benefits, according to the study.
Population turnover in prisons amplified the community-wide benefits of screening programs, as individuals move between correctional facilities and their communities, the researchers noted. This dynamic underscores the broader public health importance of prison-based interventions.
What this means
Frequently asked questions
Why is tuberculosis screening in prisons important for the general population?
People move frequently between prisons and communities, creating transmission bridges. The Liu et al. study shows that prison screening can reduce population-wide TB incidence by up to 28% because it interrupts these transmission chains.
Which screening method works best in prison settings?
Chest X-ray with computer-aided detection (CXR-CAD) proved most effective, detecting both symptomatic and asymptomatic cases. This technology outperformed symptom screening alone and was more practical than pooled sputum testing, according to the PLOS Medicine study.
How cost-effective is prison tuberculosis screening?
The most practical approach (entry and exit screening) costs $80-$140 per disability-adjusted life year averted, well below standard cost-effectiveness thresholds, according to the study. This makes it highly attractive for public health investment.
These findings provide robust evidence for scaling up systematic tuberculosis screening in correctional facilities across Latin America and similar high-burden regions. The mathematical models demonstrate that targeted interventions in high-risk populations like prisons can generate substantial population-wide health benefits while remaining economically viable for health systems.
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