Trypanosoma cruzi is a blooded-flagellated protozoan transmitted to humans either by blood-sucking
triatomine vectors, by blood transfusion or by congenital transmission causing the Chagas’ disease or American
Trypanosomiasis. Serologic testing for specific antibodies to T. cruzi antigens is the most common employed approach for
diagnosing chronic infection with this protozoan parasite in clinical patients as well as in blood donors. No assay has been
universally accepted as the gold standard for the serologic diagnosis of T. cruzi infection, and likewise no assay is viewed
as a definitive confirmatory test. Therefore, the antigen fractions (antigenic extract form, recombinant antigens and/or
synthetic peptides) may have different affinities for both specific and non-specific antibodies and can produce variable
sensitivities. To date, excreted-secreted antigens by the parasites have been proposed as antigen fractions for the detection
of this parasite: Trypomastigote Excretory-Secretory Antigens (TESA), composed mainly of surface components such as
SAPA, Gala1-3Gal, Tc-85 and T-DAF epitopes and excreted dismutase (SODe) appears to provide good sensitivity and
specificity as reagents for the diagnosis of Chagas’ disease. This chapter revises the research on excreted/secreted antigens
and their utility to establish an ideal diagnostic confirmatory Chagas test.
