[Concordance of two serological tests for the diagnosis of Chagas disease]. / Concordancia de dos pruebas serológicas para el diagnóstico de la enfermedad de Chagas.

ABSTRACT

OBJECTIVE: Establish the concordance between in-house ELISA and IIF for the diagnosis of infection with T. cruzi using blood eluates. METHODOLOGY: A study of diagnostic technology evaluation and cross-sectional sample of 650 residents of an endemic area of Colombia was conducted. It was determined the Receiver Operating Characteristic curve (ROC) and IIF was used as a gold standard. It was established the cutoff for the ELISA and the correlation between readings. RESULTS: The in-house ELISA it was an agreement of 0.99 (95 % CI 0.989 to 0.992) between the two readings taken and the area for the ROC curve was 0.9795. The cutoff was set at 0.5 absorbance in the ELISA test. 16.6 % were positive by ELISA and 10.9 % by IIF. CONCLUSIONS: The in-house ELISA showed good concordance compared to the IIF, so it is a good choice diagnostic for the population living in remote areas.