Orally transmitted Chagas disease outbreaks in Latin America: a comprehensive systematic review and public health implications

Abstract

Objective Food-borne Chagas disease is an emerging public health concern in South America, yet key aspects of its epidemiology and clinical impact remain poorly characterized. This systematic review aimed to systematically synthesize the available evidence on food-borne Chagas disease outbreaks in order to characterize their epidemiological, clinical, laboratory, treatment, and follow-up features, and to identify major knowledge gaps. Methods A systematic review of food-borne Chagas disease outbreaks reported between 1965 and 2024 was conducted following PRISMA-2020 guidelines (PROSPERO-CRD42024542461). Independent reviewers screened studies and extracted data on epidemiology, food sources, diagnostics, clinical presentation, treatment, follow-up, seasonality, vectors, and parasite lineages. Results Among 835 records identified, 111 studies met the inclusion criteria, describing 114 outbreaks in six countries, comprising 1,293 cases and 77 deaths (case fatality rate: 5.95%). Reported outbreaks increased 7.1-fold during the second half of the study period. Food sources were epidemiologically identified in only 12 outbreaks, with microbiological confirmation achieved in just one of them. In a further 82 outbreaks, the implicated food vehicle was classified as suspected based on epidemiological evidence, while no food source was identified in the remaining 20 outbreaks. Açaí was the most frequently implicated food in Brazil (32/64 outbreaks), whereas fruit-based beverages predominated elsewhere. Outbreaks clustered in Amazonian and tropical regions and occurred mainly during warm and rainy seasons, with predominance of sylvatic TcI/TcIV lineages and frequent involvement of Rhodnius spp. vectors. The median incubation period was 16 days. Clinical information was available for 941 patients, revealing a predominantly acute febrile syndrome (83.6%), followed by headache (37.1%), myalgia (36.4%), and facial edema (25.4%). Cardiac evaluation in 501 patients showed a substantial burden of abnormalities, including pericardial effusion (29.3%), repolarization disorders (26.3%), tachycardia (18.5%), bundle branch blocks (8.4%), and heart failure (7.2%). Follow-up data suggested persistence of cardiac alterations despite treatment, while long-term serological and molecular outcomes indicated low seronegativization and possible parasite persistence even after 10 years. Conclusion Food-borne Chagas disease remains an important mode of T. cruzi transmission, particularly in Amazonian and sylvatic settings. However, substantial heterogeneity, underreporting, and inconsistent diagnostic and follow-up practices limit current understanding. Standardized outbreak investigations, long-term cohort studies, and strengthened surveillance systems are urgently needed. Systematic review registration PROSPERO 2024 CRD42024542461. Available online at: https://www.crd.york.ac.uk/PROSPERO/view/CRD42024542461.