Evaluation of a Novel Peptide-Based ELISA for the Serological Diagnosis of Trypanosoma cruzi Infection.

Chagas disease is a neglected tropical disease endemic in most of the Americas, caused by Trypanosoma cruzi. New serological tests with improved performance are urgently needed for accurate diagnosis of T. cruzi infections. We evaluated here the performance of a novel peptide ELISA based on highly conserved parasite antigens, using a large panel of well characterized samples (N = 308) from Mexico, where serological discordance is particularly high. Comparison of peptide ELISA with various serological and molecular assays indicated that it outperformed an FDA-approved commercial ELISA in terms of sensitivity (47.5% vs. 28.3% compared with PCR), while a high specificity was maintained (80.3%-91.2% compared with PCR or serology plus PCR). Improved sensitivity was due to the reactivity of samples previously characterized as serodiscordants. Nonetheless, test performance remains limited for stand-alone use but may complement current tests. Further optimizing antigen composition to include additional highly conserved antigens may allow reaching optimum levels of test performance to simplify serological diagnosis of T. cruzi infection.