Evaluation of UMELISA CHAGAS™ with the incorporation of new monomeric and chimeric peptides representative of different regions of Trypanosoma cruzi.

Introduction: Most people with Chagas disease develop specific antibodies against Trypanosoma cruzi. In early infection, IgM antibodies against T. cruzi are produced and later replaced for IgG antibodies during the course of the disease. The first symptoms of the infection may be very mild and atypical, which is why the disease is often not detected in the acute phase. Objectives: To evaluate the clinical and analytical sensitivity, and specificity, accuracy, and efficacy of UMELISA CHAGAS™ with the addition of new synthetic peptides in the solid phase representative of the shed acute phase antigen protein (SAPA) and the trypomastigote surface antigen (TSA). Materials and methods: We evaluated a mixed anti-T. cruzi titer performance panel and a Chagas seroconversion one, as well as positive and negative serum samples from endemic areas of the disease and positive samples for other diseases that may interfere with the assay. The Bioelisa CHAGAS assay, Chaga test recombinant ELISA v.4.0, Chagatest HAI, and SD BIOLINE CHAGAS Ab Rapid were used as reference tests. Results: The sensitivity of the assay was 97.73% (95% CI: 96,23-99,24) and the clinical specificity, 99.33% (95% CI: 98,88-99,78) while the efficacy and the accuracy were 98.96%. Conclusions: Our results show that the new solid phase of UMELISA CHAGAS® can be used for immunodiagnostic, blood certification, and epidemiological surveillance in endemic and non-endemic countries with high-risk populations.