# Oral Route Infection by Trypanosoma cruzi: From the Beginning to the Present Day

## TL;DR

This paper reviews the history and current understanding of how Trypanosoma cruzi, the parasite causing Chagas disease, can be transmitted through the oral route, including food and meat consumption.

## Contribution

The paper provides a comprehensive analysis of oral transmission of T. cruzi, integrating clinical, epidemiological, and experimental findings.

## Key findings

- Oral transmission of T. cruzi was confirmed in 1968, but was long considered rare.
- Experimental studies in mice have clarified the molecular mechanisms of oral infection.
- Foodborne outbreaks and consumption of infected meat highlight the significance of oral transmission.

## Abstract

Trypanosoma cruzi is the causative agent of Chagas disease, which affects 6–7 million people worldwide. Although the possibility of oral transmission was first scientifically suggested in 1913, it was not until 1968 that the first confirmed cases of human infection via food consumption were reported. This long gap contributed to the widespread perception that oral transmission was a rare or incidental event. Over the past two decades, significant advances have been made in understanding the biological and clinical aspects of oral transmission, including the molecular mechanisms by which metacyclic trypomastigotes establish infection via the digestive route. Experimental studies in murine models have further deepened our knowledge of the biology and pathogenesis of oral infection. Concurrently, multiple outbreaks of T. cruzi infection through contaminated food and beverages have been reported across Latin America, providing valuable insights into the molecular epidemiology and clinical characteristics of this transmission route. Moreover, experimental evidence has shown that the consumption of meat from animals infected during the acute phase can also lead to T. cruzi infection, highlighting carnivory as a potential alternative transmission mechanism. This review aims to comprehensively analyze oral infection by T. cruzi, considering clinical and epidemiological data, parasite biology, and findings from murine experimental models. Strategies for controlling foodborne transmission of Chagas disease are also discussed.