[Detection of antibodies against Trypanosoma cruzi in blood donors].

American trypanosomiasis is an endemic disease in Mexico. Blood transfusion has been recognized as the second main mechanism of transmission in South American countries. There is no definitive information available for Mexico. We obtained the prevalence of IgG antibodies against Trypanosoma cruzi among 1076 blood donors at the Instituto Nacional de Cardiología "Ignacio Chávez" in Mexico City. We used an antigen freshly prepared from local isolates, and the complete and soluble antigen preparations were analyzed with the Western blot technique using sera previously characterized as reactive. Blood donors' antibodies were studied with DOT-ELISA and Western blot. All donors were asked in regard to place of birth, and blood samples were serologically tested as usual in transfusion practice. The presence of IgG antibodies to T. cruzi, confirmed with a high-specificity test, showed a prevalence of 0.28 per cent. Screening for antibodies to T. cruzi; should be included in the evaluation of blood donors in Mexico.