Chagas' disease diagnosis: comparative analysis of recombinant ELISA with conventional ELISA and the haemagglutination test

Background and Objectives Serological screening for Chagas' disease in the blood banks of South America is carried out by using two different assays that generally show a high number of inconclusive results. To establish a combination of two tests that can minimize the number of inconclusive results, we compared a recombinant enzyme-linked immunosorbent assay ( ELISA) with two conventional tests. Materials and Methods Serum samples from chagasic patients ( n = 112), from nonchagasic individuals ( n = 143) and from patients with other diseases ( n = 32) were tested using three assays: recombinant ELISA ( Rec-ELISA); conventional ELISA (Con-ELISA); and the indirect haemagglutination (IHA) test. Results When we evaluated the data by matching the Rec-ELISA and the IHA test, 52 inconclusive results were obtained. When Rec-ELISA and Con-ELISA were matched, only four inconclusive results were observed. Conclusions Our investigation indicates that the use of two ELISAs with different antigen preparations provides an effective test combination for blood bank screening of Chagas' disease.