Development and evaluation of an enzyme linked immunotransfer blot technique for serodiagnosis of Chagas' disease.

An enzyme linked immunoelectrotransfer blot technique (EITB) was developed and evaluated for the serodiagnosis of Chagas' disease. EITB strips were prepared using Trypansoma cruzi (Y strain) epimastigotes lysate. Evaluation was performed with 235 serum samples collected from individuals living in an endemic area for Chagas' disease. Among those samples, 160 were serological positive in three conventional tests for T. cruzi and 75 were negative. The specificity was determined using 37 serum samples from patients with other infectious diseases. The EITB test showed sensitivity of 99.3% and specificity of 100% when a positive reaction was defined as the presence of 3 bands from a group of 7 (14, 19, 27, 30, 34, 37 and 75), a negative reaction was defined as the absence of 6 of the 7 bands, and an indeterminate reaction as the presence of two of the 7 bands.