Simultaneous use of two rapid diagnostic tests for the diagnosis of Chagas disease.

The sensitivity of rapid diagnostic tests (RDT) for Chagas disease is not great enough for their single use. The aim of this paper was to evaluate the performance of two RDTs for Chagas disease, used simultaneously. Two different RDTs (A and B) were performed in 64 and 42 serum samples that were negative and positive, respectively, by conventional serological techniques. Validity and reliability of both tests were evaluated individually and simultaneously. Sensitivity was 90.5% and 97.6%, and specificity was 100% and 93.8%, for RDT A and B, respectively. The kappa statistic was 0.96. When both RDTs were used simultaneously, sensitivity was 97.4%, specificity was 100% and the discordance percentage 6.6%. The combined use of two RDTs with serum samples is an acceptable application in healthcare centres.