Hidden Threats: How Parasitic and Viral Infections in Detained Migrants Are Overlooked
"Unseen Infections: Exploring the Prevalence of Neglected Tropical Diseases and Viral Infections Among Detained Migrants"
Detention centers, often unseen by the public eye, can be hotspots for a range of health issues. While these facilities are designed to house individuals awaiting legal proceedings or serving sentences, they also inadvertently become environments where infectious diseases can spread. This is particularly concerning for migrant populations, who may arrive with pre-existing health conditions, including neglected tropical diseases (NTDs) and viral infections.
A recent study published in the Journal of Tropical Medicine sheds light on this critical issue, focusing on detained migrants from sub-Saharan Africa and Latin America. The research reveals a troubling reality: a high prevalence of persistent parasitic infections such as strongyloidiasis and schistosomiasis, alongside viral infections like HIV, hepatitis B (HBV), and hepatitis C (HCV). These findings underscore the urgent need for increased awareness and intervention within detention settings.
This article explores the study's key findings, their implications for public health, and the importance of addressing these often-overlooked health challenges. We will examine the specific diseases, the study's methodology, and the potential impact of these infections on both the individuals affected and the broader community.
An Undermeasured Health Burden
The health effects of parasitic and viral infections among detained migrants are difficult to quantify because systematic data on detainee health and health-care provision remain limited. This uncertainty can allow infectious conditions and other health needs to receive insufficient attention, particularly in settings where independent monitoring is restricted. The available evidence supports treating detention as a setting requiring stronger health surveillance rather than assuming that reported cases represent the full burden.
Standards Without Sufficient Oversight
The 2023 evaluation of US detention standards examined whether requirements across detention agencies adequately protect migrants’ health and dignity. The WHO evidence brief reports major limitations in official health-care information, restricted access for independent monitoring bodies in many countries, and gaps in detention health care. Together, these findings indicate that written standards and routine institutional procedures may not reliably reveal or address infectious-health risks in detention facilities.
A Longstanding Systemic Problem
Clinicians and observers have documented overcrowding, poor hygiene, and inadequate sanitation in US immigration detention. The detention system regularly held more than 30,000 people per day during the decade discussed by the 2022 study, and the daily population exceeded 52,000 in 2019 before the pandemic. More recent research has also described health-related experiences among detained immigrants with and without mental illness, showing that detention health concerns extend across different groups.
The Silent Threat: Unveiling the Prevalence of Parasitic and Viral Infections
The study, conducted in a pretrial detention center in Geneva, Switzerland, provides a sobering look at the health status of detained migrants. Researchers examined a cohort of 201 participants, the majority of whom originated from sub-Saharan Africa. The study's findings reveal a significant burden of infectious diseases, highlighting the complex interplay of parasitic and viral infections.
- HIV: 3.5% of participants tested positive, with the highest prevalence among those from sub-Saharan Africa.
- Chronic HBV: A substantial 12.4% of participants showed signs of chronic hepatitis B infection, primarily impacting the sub-Saharan African population.
- Viraemic HCV: 2.0% of participants had active hepatitis C infection, with slightly higher rates among Latin American detainees.
- Strongyloidiasis: The study found an 8.0% prevalence of strongyloidiasis, a parasitic infection.
- Schistosomiasis: A notable 20.3% of participants from sub-Saharan Africa tested positive for schistosomiasis, a parasitic disease endemic to the region.
Evidence Remains Incomplete
Recent research and reviews suggest that detention-related health harms are recognized, but the evidence base remains uneven. The available material points to gaps in health data, health-care documentation, and independent access to facilities. This makes it difficult to determine how often infectious diseases are detected promptly or how consistently prevention and treatment are delivered.
Detention Can Worsen Health
Arguments that detention can manage migration must be weighed against evidence that it negatively affects health. The Lancet discussion states that immigration detention has become increasingly used despite international law identifying it as a last resort and stating that children should never be detained. It also reports that chronic physical or mental health conditions may not be managed appropriately in detention, while people without pre-existing conditions can develop health problems during detention.
Alternatives and Health Planning
WHO guidance compares detention with engagement-based alternatives and presents alternatives to detention as part of a broader health-policy approach. Its country implementation guide summarizes evidence, best practices, international commitments, and practical considerations for addressing the health challenges of refugees and migrants in detention. The guidance is intended not only for detention managers but also for policy-makers, health planners, ministries, and international organizations.
A Call to Action: Protecting Vulnerable Populations
The study's findings serve as a crucial reminder of the importance of addressing health challenges within detention settings. The high prevalence of persistent infections among detained migrants underscores the need for targeted interventions, including screening programs, early diagnosis, and appropriate treatment. Collaboration between healthcare providers, policymakers, and community organizations is essential to ensure that vulnerable populations receive the care they need, ultimately improving their health outcomes and reducing the risk of disease transmission. This research highlights the importance of a proactive approach to healthcare, especially for those who are often marginalized and underserved.
Visibility Is a Health Intervention
The available evidence suggests that overlooked infections are part of a wider detention-health problem shaped by incomplete information, limited oversight, and harmful living conditions. A credible response therefore requires more than clinical treatment after illness appears. It also requires dependable health reporting, independent monitoring, and conditions that do not make prevention and continuity of care harder.
Duration and Health Risk
A 2025 cross-sectional study examined whether detention lasting six months or more was associated with poor health, mental illness, and posttraumatic stress disorder among recently detained US immigrants. The KFF brief examines recent detention trends using Immigration and Customs Enforcement data alongside health-care risks and challenges in detention facilities. Together, these sources point toward closer study of detention duration, population trends, and the health-care consequences of prolonged confinement.
Health Inequity Beyond the Facility
The broader literature links restrictive immigration policies to pressure on public health systems, social services, and community cohesion. CDC guidance notes that immigrant, refugee, and migrant communities are often unequally affected by economic, social, and other barriers to health. Research on structural violence and health disparities therefore places detention-related health risks within wider systems that can deepen existing inequities.
Health Consequences for Detainees
A 2026 systematic review of 14 studies found consistent evidence that mental health diagnoses and symptoms were highly prevalent among immigration detainees. Although this review focuses on mental health rather than parasitic or viral infection, it illustrates the substantial human burden associated with detention. Any assessment of overlooked infectious disease should therefore account for the broader health consequences experienced by people held in detention.