Molecular detection of Trypanosoma cruzi and co-circulating trypanosomatids in the Pan-Amazon: a systematic review and meta-analysis of PCR/qPCR evidence across One Health interfaces

Chagas disease (American trypanosomiasis), caused by Trypanosoma cruzi, is sustained in the Pan-Amazon by complex transmission across humans, insect vectors, wildlife and domestic reservoirs, and food-related pathways. Despite the widespread use of PCR and qPCR for detection, molecular evidence remains fragmented across One Health interfaces and is often difficult to compare due to ecological diversity and methodological heterogeneity.
This project compiles, curates, and synthesizes peer-reviewed molecular evidence (2010–2025) on T. cruzi detection and co-circulating trypanosomatids in Pan-Amazon settings using a systematic review and meta-analysis framework aligned with PRISMA 2020. We focus on PCR/qPCR-confirmed detection and stratify evidence into four prespecified One Health interfaces: (1) human infection, (2) vector/reservoir surveillance, (3) bushmeat/tissue exposure contexts, and (4) food/drink matrices (including foods, beverages, and processing environments).
Purpose and objectives. The primary purpose is to quantify how molecular detection of T. cruzi varies across One Health interfaces in the Pan-Amazon and to characterize the magnitude of heterogeneity across settings. Specifically, we aim to: (i) estimate pooled PCR/qPCR detection proportions overall and by interface; (ii) evaluate heterogeneity using I², τ², and prediction intervals; (iii) assess how detection varies by key moderators such as assay type (PCR vs qPCR), molecular targets (e.g., satDNA, kDNA, ribosomal markers), geography, and transmission-source categories; and (iv) document evidence of co-circulating trypanosomatids (e.g., T. rangeli, T. evansi) that may complicate interpretation when assays are not species-specific.
Methods overview. Eligible studies are peer-reviewed primary research articles published from 1 January 2010 to 31 December 2025 that report PCR/qPCR detection with extractable numerator/denominator data in Pan-Amazon locations. Quantitative synthesis is conducted under a random-effects framework using binomial GLMM models (logit link) to accommodate sparse data and boundary proportions without continuity corrections. Dependence due to multiple effect sizes from the same study is handled using multilevel modeling and dependence-robust inference where appropriate, with prespecified subgroup analyses and sensitivity analyses (e.g., excluding “unclear” transmission-source classifications).
Expected outcomes and outputs. This OSF repository will host the study protocol/registration materials, analysis-ready extracted datasets, full statistical scripts, figures, and supplementary materials supporting the manuscript. Expected outcomes include pooled estimates of molecular detection across One Health interfaces, interface-specific heterogeneity characterization (including prediction intervals reflecting real-world variability), and a structured synthesis of co-circulating trypanosomatids relevant to surveillance and diagnostic interpretation. The repository is intended to strengthen transparency and reproducibility, support future updates/expansions of the evidence base, and inform One Health surveillance priorities and outbreak-response readiness in the Pan-Amazon region.