Chagas' disease: application of TESA-blot in inconclusive sera from a Brazilian blood bank.
OBJECTIVE
The procedure used for screening Trypanosoma cruzi-infected blood donors by using two serological techniques has frequently led to discordant results. The TESA-blot, a confirmatory test for Chagas' disease, was applied in a survey of inconclusive sera from a Brazilian blood bank.


METHODS
Four hundred and forty-eight sera, obtained from blood donors at the HRU-Fundação Hemominas, were tested by using the TESA-blot assay, a Western blotting method. Of these 448 sera, 348 had previously been determined as inconclusive for Chagas' disease owing to discordance between the indirect immunofluorescence assay (IFA) and the enzyme-linked immunosorbent assay (ELISA).


RESULTS
The TESA-blot was positive for 2.87% (10/348) of the inconclusive sera, and 100% positive and negative for the sera from chagasic (n=50) and non-chagasic (n=50) donors, respectively.


CONCLUSIONS
Our results clearly indicate the need to improve the diagnosis of Chagas' disease in blood banks by using new confirmatory diagnostic test(s). The TESA-blot, a new test with trypomastigote fractions of the T. cruzi Y strain, has made new approaches to the confirmation of Chagas' disease possible.
Silveira-Lacerda
E P
EP
Universidade Federal de Uberlândia, Instituto de Genética e Bioquímica, Minas Gerais, Brazil.
Silva
A G
AG
Junior
S F
SF
Souza
M A
MA
Kesper
N
N
Botelho-Filho
A
A
Umezawa
E S
ES
D000293:Adolescent; D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001771:Blood Banks; D001782:Blood Donors; D015153:Blotting, Western / Q000379:methods*; D001938:Brazil / Q000453:epidemiology; D014355:Chagas Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D003951:Diagnostic Errors; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D012698:Serologic Tests / Q000379:methods; D014349:Trypanosoma cruzi / Q000276:immunology
D000913:Antibodies, Protozoan