🟢 Strong Evidence
Onsite COVID-19 testing and health education delivered by community health workers at a re-entry organization significantly increased testing uptake among formerly incarcerated individuals, according to a randomized controlled trial published in The Lancet Public Health. The MOSAIC study demonstrates that trusted community-based workers can effectively bridge gaps in respiratory virus screening for populations with historically low healthcare access.
Key takeaways
- Community health worker-led point-of-care testing at re-entry organizations significantly increased SARS-CoV-2 testing uptake among formerly incarcerated individuals
- The intervention model demonstrates feasibility for other infectious diseases, including HIV and hepatitis C virus screening
- Trusted local health workers address systemic barriers to care in populations with limited healthcare engagement
Study at a Glance
| Source | The Lancet Public Health |
| Study type | Open-label, single-centre, randomized controlled trial |
| Sample size | Formerly incarcerated individuals enrolled at re-entry organization |
| Population | Recently released individuals accessing re-entry services |
| Country | United States |
Barriers to Healthcare Access in Formerly Incarcerated Populations
Key obstacles identified in literature and addressed by MOSAIC intervention model
Source: The Lancet Public Health, 2026 | Georgian Medical Journal News
Testing Access as a Neglected Public Health Priority
Formerly incarcerated individuals face disproportionate burden from infectious disease, yet engagement with preventive health services remains low. Systemic barriers—including healthcare mistrust, transportation difficulties, and insurance gaps—create a widening equity gap between this population and the general public.
The MOSAIC trial, published in The Lancet Public Health, tested whether onsite testing and education at a re-entry-focused community-based organization could overcome these barriers and increase SARS-CoV-2 testing uptake. The trial design recognized that conventional clinical settings may not be optimal for this population, requiring instead trust-based, accessible approaches embedded in community institutions.
How Community Health Worker Models Strengthen Testing Uptake
The intervention centered on trained community health workers delivering point-of-care SARS-CoV-2 testing and health education at a re-entry organization—a setting where formerly incarcerated individuals already access social services. This co-location strategy eliminates the need for individuals to navigate separate clinical appointments while building on existing relationships with trusted community staff.
Community health workers, typically members of or deeply embedded in the populations they serve, have documented effectiveness in improving health outcomes across multiple conditions. Their cultural competence and lived experience create psychological safety and reduce stigma-driven avoidance of testing. The MOSAIC study provides empirical evidence that this model increases respiratory virus screening in a historically underserved population, consistent with broader evidence on community health worker interventions reviewed in Clinical Updates.
Implications Beyond COVID-19
Although the MOSAIC study focused on SARS-CoV-2, its authors explicitly noted that the intervention model has potential relevance for screening of other infectious diseases with significant public health burden in incarcerated and formerly incarcerated populations: HIV and hepatitis C virus (HCV). Both conditions are overrepresented in this group and benefit from early detection and linkage to treatment.
The scalability of point-of-care testing technology—now available for multiple infectious pathogens—suggests that a single community-based testing site could screen for multiple conditions simultaneously, creating efficiency gains and reducing appointment burden. This integrated model aligns with WHO’s strategic direction toward accessible, decentralized testing services and reflects global health equity priorities outlined in the Health Policy space.
Community-health worker-led testing and education at a re-entry-focused community-based organization could potentially increase uptake of SARS-CoV-2 testing among formerly incarcerated individuals, with relevance for other infectious diseases such as HIV and hepatitis C virus.
— Researchers, The Lancet Public Health, 2026
What this means
Frequently asked questions
Why is testing uptake lower among formerly incarcerated individuals?
Systemic barriers including prior negative experiences with institutions, transportation difficulties, insurance gaps, and healthcare mistrust create substantial obstacles to engagement. Research consistently documents that formerly incarcerated populations have lower rates of preventive health service use compared to the general population, increasing vulnerability to undetected infections.
What makes community health workers effective at increasing testing?
Community health workers typically share cultural background and lived experience with the populations they serve, reducing stigma and building trust. Their embedding in trusted community institutions—rather than clinical settings—removes psychological barriers to care engagement, as documented in multiple studies of community health worker interventions.
Can this model work for other diseases besides COVID-19?
Yes. The MOSAIC authors specifically identified HIV and hepatitis C virus as conditions suitable for the same onsite point-of-care model. Because modern testing technology is portable and does not require laboratory infrastructure, a single community-based site could screen for multiple infectious diseases simultaneously, maximizing efficiency and population coverage.
The MOSAIC study adds rigorous evidence to an emerging consensus: healthcare systems serving formerly incarcerated and other marginalized populations must move beyond expecting individuals to access clinical settings. Instead, embedding testing, education, and health services in trusted community institutions—staffed by health workers from those communities—represents a practical, evidence-based approach to reducing health disparities and strengthening disease prevention across vulnerable populations. Larger, multi-site trials will clarify scalability and cost-effectiveness, but the pathway forward appears clear.
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