Chagas disease (ChD) is a a neglected tropical disease caused by the triatomine vector Trypanosoma cruzi ("kissing bugs"). ChD has experienced a major epidemiologic shift marked by declining prevalence, changing transmission pathways, and the effects of urbanization and globalization. Once primarily a rural, vector-borne infection in Latin America, it has decreased in many countries due to successful control efforts, resulting in a population profile in which most people living with ChD are now adults with chronic infection. Nonetheless, substantial transmission persists in settings such as the Gran Chaco, and increasing recognition of oral transmission in the Amazon basin adds further complexity. At the same time, movement from rural areas into cities and migration to non-endemic regions—especially Europe and the United States—has expanded and redistributed disease burden beyond traditional endemic zones. Together, these dynamics make ChD prevalence harder to quantify, a challenge compounded by limited recent data, infrequent population-based surveys, and continued dependence on outdated estimation models.^2,1

Chagas disease (ChD) has undergone a marked epidemiological transition shaped by sustained vector-control successes, demographic change, and globalization. Once predominantly a rural, vector-borne infection across Latin America, ChD prevalence has declined in many settings as control programs reduced domestic vector transmission, producing a population shift in which most people living with ChD are now adults with long-duration chronic infection. Yet transmission has not been eliminated: persistent hotspots such as the Gran Chaco continue to sustain risk, while emergent oral transmission in the Amazon basin introduces additional ecological and surveillance complexity. In parallel, urbanization and migration—from rural to urban centers and into non-endemic countries in Europe and the United States—have expanded the importance of non-vector routes (notably congenital transmission) and relocated disease burden into health systems that may have limited routine screening and clinical familiarity. These changes also complicate prevalence estimation, with substantial uncertainty driven by sparse contemporary surveys, uneven surveillance, and continued reliance on dated datasets and modeling assumptions that may not capture current mobility patterns or evolving transmission dynamics.^1,2

Chagas disease is increasingly recognized as a public health issue in Europe, where Trypanosoma cruzi transmission is no longer primarily vector-borne but instead driven by population mobility and vertical (congenital) transmission. In this context, the model proposed by Maraffa, et. al, evaluates whether systematically screening pregnant women at risk of Chagas disease in Italy—and testing their newborns when maternal infection is identified—represents good value for the Italian National Health Service (SSN). Italy is a particularly policy-relevant setting: it hosts one of Europe’s largest Latin American migrant communities, and the authors cite an estimated Chagas prevalence around 3.5% among this population, implying a non-trivial pool of undiagnosed infections with preventable congenital cases.¹

Methodologically, the authors conduct a cost-effectiveness analysis comparing a “screening” scenario to a “no-screening” counterfactual from the SSN perspective. They implement a Bayesian decision-tree model with a lifetime time horizon, which is important because the health and economic consequences of congenital infection can unfold over decades (e.g., chronic cardiac or gastrointestinal sequelae), and because early detection can avert downstream morbidity. The model translates screening-linked case identification into long-run health outcomes quantified as quality-adjusted life years (QALYs), allowing comparison to conventional willingness-to-pay thresholds used in Italy.¹

The central result is that a congenital Chagas screening strategy is cost-effective under base-case assumptions, yielding an incremental cost-effectiveness ratio (ICER) of **€15,193 per QALY gained** (95% CI: **€14,885–€15,552**). This estimate sits comfortably below commonly cited Italian thresholds of **€30,000–€50,000 per QALY**, indicating that the health gains achieved through earlier detection and management of maternal and/or infant infection are obtained at a cost that health systems would typically consider acceptable. The authors further report that probabilistic sensitivity analysis supports the robustness of this conclusion, suggesting that uncertainty in key parameters (e.g., prevalence in the screened population, test performance, uptake, or downstream costs) is unlikely to overturn the overall policy signal.¹

The policy implication is explicit. Congenital Chagas screening in at-risk pregnant women can be integrated into existing maternal care pathways as a national program, aligning with international priorities to reduce the burden of neglected tropical diseases while advancing migrant health. Conceptually, the paper reframes Chagas control in non-endemic settings as an implementation challenge embedded in routine care rather than an "exotic" tropical medicine problem, rather into one in which maternity services become a pragmatic leverage point for prevention.²

Viewed through an infectious disease microbiology and global health equity lens, this cost-effectiveness result is also an argument about what populations benefit from health system resources and when. Chagas disease is biologically tractable, diagnosable, preventable in congenital transmission, and treatable. However, it persists in non-endemic countries largely because migrants and other marginalized groups encounter predictable barriers across the care cascade (risk recognition, screening, confirmatory testing, treatment access, and follow-up), a pattern emphasized in the implementation and health systems literature. A national screening program embedded in routine antenatal care operationalizes equity by shifting detection from chance to design, but its real-world success depends on culturally responsive engagement, clinician training, and guaranteed pathways to confirmatory diagnostics and therapy for both mother and infant. Framing Chagas as simultaneously a microbiological infection and a minority health issue keep the focus on preventing avoidable chronic cardiac and gastrointestinal disease in communities that have historically been expected to carry silent risk. This framework is able to turn an infectious disease often neglected by healthcare funding and resources and disproportionately affects marginalized communities, into a measurable standard of health-system accountability.²

References

1. Marraffa, P., Dentato, M., Nurchis, M.C. et al. Cost-effectiveness analysis of screening for congenital Chagas disease in a non-endemic area. Nat Commun 16, 8707 (2025). https://doi.org/10.1038/s41467-025-63760-0

2.  Ribeiro, A.L.P. and The RAISE Study Collaborators (2024) ‘The Burden of Chagas Disease in the Contemporary World: The RAISE Study’, <i>Global Heart</i>, 19(1), p. 2. Available at: https://doi.org/10.5334/gh.1280.