Resumen

Background: The origin (native or non-native) of Trypanosoma cruzi strains used as substrate for immunoassays may influence their performance. Objective: To assess the performance of an immunoassay based on a native T. cruzi strain compared to another based on non-native T. cruzi strains, in asymptomatic blood donors from Mexico. Methods: Serum samples from a tertiary referral center were tested by both ELISA-INC9 (native) and Chagatest (non-native) assays. All reactive serum samples were further analyzed by indirect immunofluorescence. Results: Sera from 1,098 asymptomatic blood donors were tested. A  4.3  and 0.7% serum reactivity prevalence was observed using ELISA-INC9 and Chagatest, respectively (kappa = 0.13; −0.11 to 0.38). Subsequently, indirect immunofluorescence analyses showed higher positivity in serum samples reactive by ELISA-INC9 compared to those reactive by Chagatest (79 vs. 62.5%; p < 0.001). Furthermore, out of the 47 positive samples by both ELISA-INC9 and indirect immunofluorescence, only four (8.5%) were reactive in Chagatest assay. Meanwhile, four (80%) out of the five positive samples by both Chagatest and indirect immunofluorescence were reactive using ELISA-INC9. Conclusion: Immunoassays based on a native T. cruzi strain perform better than those based on non-native strains, highlighting the need to develop and validate screening assays in accordance to endemic T. cruzi strains.

Palabras clave: Chagas disease trypanosoma cruzi immunoassay

2017-02-02   |   469 visitas   |   Evalua este artículo 0 valoraciones

Vol. 68 Núm.6. Noviembre-Diciembre 2016 Pags. 286-291 Rev Invest Clin 2016; 68(6)