Direct and indirect methods used for the diagnosis of the Chagas disease in acute and chronic phase

Abstract

Chagas disease or American trypanosomiasis is an infection caused by Trypanosoma Cruzi. This flagellated blood parasite reproduces in tissues and organs. Chagas disease presents two phases. The acute phase can be asymptomatic and the chronic phase that is characterised by symptoms that could affect not only the digestive and nervous system but the heart. This review aims to depict the main diagnostic direct and indirect methods of Chagas disease which have been applied to acute and chronic phases respectively. However, Chagas disease diagnosis does have some limitations: low sensitivity of indirect methods, related to low blood parasite concentration, and low specificity of parasitological methods. Therefore, the WHO recommends that two tests should be performed in parallel on different principles or using different antigens to establish a proper diagnosis of the disease. Although there are several diagnostic methods, there is no specific test to diagnose this pathology, as the effectiveness of the diagnosis depends on the antigen used and the stage of the disease.