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


METHODS
Serum samples from chagasic patients (n = 112), from non-chagasic 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.
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan; D016022:Case-Control Studies; D014355:Chagas Disease / Q000175:diagnosis* / Q000276:immunology*; D003951:Diagnostic Errors; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods* / Q000706:statistics & numerical data; D006386:Hemagglutination Tests / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D008875:Middle Aged; D015800:Protozoan Proteins / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology; D012680:Sensitivity and Specificity; D014349:Trypanosoma cruzi / Q000276:immunology*
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D015800:Protozoan Proteins; D011994:Recombinant Proteins