Standardization of Dot-ELISA for detection of anti-Trypanosoma cruzi antibodies, compared to ELISA and 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. (C) 2013 Elsevier Espana, S.L. All rights reserved.