[Standardization of Dot-ELISA for detection of anti-Trypanosoma cruzi antibodies, compared to ELISA and Western blot]. / Estandarización de la técnica Dot-ELISA para la detección de anticuerpos anti-Trypanosoma cruzi y su comparación con ELISA y Western blot.

INTRODUCTION: Chagas disease is considered endemic of Latin America. Because of migration of people from this region to non-endemic areas, such as the United States, Canada and Europe, it has become a major health problem. There are parasitology and serology tests for its diagnosis, but only the latter are useful during the chronic phase. Most of these tests require expensive equipment, which make them also inaccessible for laboratories in endemic areas. In the present work we standardize Dot-ELISA as a diagnostic test for Trypanosoma cruzi infection, since it is an easy, inexpensive and an accessible test. METHODS: A total of 360 samples were tested: 96 sera from Chagas patients and 153 from healthy people; 40 blood samples spots collected and eluted from filter paper were also tested, as well as 71 serum samples of patients with non-related infections. Sensitivity, specificity and kappa index of Dot-ELISA test were calculated, in order to determine a correlation value of this technique compared to ELISA and Western blot that are already being used for diagnosis. RESULTS: Dot-ELISA obtained 97% sensitivity and 89% specificity, since it showed cross-reaction mainly with Leishmania spp., and a kappa index of 0,79. CONCLUSIONS: Dot-ELISA results correlate well with other tests that are already being used for diagnosis of Chagas disease. As it is easy and inexpensive, it may be useful as an additional diagnostic test or for field studies.

Estandarización de la técnica Dot-ELISA para la detección de anticuerpos anti-Trypanosoma cruzi y su comparación con ELISA y Western blot / Standardization of Dot-ELISA for detection of anti- Trypanosoma cruzi antibodies, compared to ELISA and Western blot

INTRODUCCIÓN: La enfermedad de Chagas es endémica de Latinoamérica. Debido a la migración de individuos de esta región a zonas no endémicas, como es el caso de Estados Unidos, Canadá y Europa, esta infección se ha convertido en un problema de salud mundial. Para realizar el diagnóstico existen pruebas parasitológicas y serológicas, pero solo las últimas son útiles durante la fase crónica. Muchas de estas técnicas requieren equipos costosos, lo que limita su uso. En este trabajo se estandarizó la técnica Dot-ELISA para el diagnóstico de la infección con Trypanosoma cruzi por ser una técnica sencilla, de bajo costo y accesible. Métodos Se evaluaron 360 muestras: 96 sueros de pacientes chagásicos y 153 de individuos sanos; 40 muestras de sangre recogidas en papel filtro, así como 71 sueros de pacientes con otras infecciones. Se calculó la sensibilidad, la especificidad y el índice kappa de Dot-ELISA en comparación con las pruebas ELISA y Western blot previamente estandarizadas para el diagnóstico de la infección por T. cruzi. Resultados Dot-ELISA obtuvo una sensibilidad del 97% y una especificidad del 89%, ya que presentó reacción cruzada principalmente con Leishmania spp. El índice kappa calculado fue de 0,79.ConclusionesDot-ELISA mostró buena correlación con otras pruebas que ya son utilizadas para el diagnóstico de la enfermedad de Chagas. Por tratarse de una técnica sencilla y económica, que puede realizarse sin equipo sofisticado, resulta ser más accesible y puede utilizarse como una prueba para un cribado inicial en el diagnóstico en el laboratorio o en estudios en campo

INTRODUCTION: Chagas disease is considered endemic of Latin America. Because of migration of people from this region to non-endemic areas, such as the United States, Canada and Europe, it has become a major health problem. There are parasitology and serology tests for its diagnosis, but only the latter are useful during the chronic phase. Most of these tests require expensive equipment, which make them also inaccessible for laboratories in endemic areas. In the present work we standardize Dot-ELISA as a diagnostic test for Trypanosoma cruzi infection, since it is an easy, inexpensive and an accessible test. METHODS: A total of 360 samples were tested: 96 sera from Chagas patients and 153 from healthy people;40 blood samples spots collected and eluted from filter paper were also tested, as well as 71 serum samples of patients with non-related infections. Sensitivity, specificity and kappa index of Dot-ELISA test were calculated, in order to determine a correlation value of this technique compared to ELISA and Western blot that are already being used for diagnosis. RESULTS: Dot-ELISA obtained 97% sensitivity and 89% specificity, since it showed cross-reaction mainly with Leishmania spp., and a kappa index of 0,79. CONCLUSIONS: Dot-ELISA results correlate well with other tests that are already being used for diagnosis of Chagas disease. As it is easy and inexpensive, it may be useful as an additional diagnostic test or for field Studies