Evaluation of the performance of Brazilian blood banks in testing for Chagas' disease

Background and Objectives: Due to the low sensitivity and reproducibility of available tests, in 1989 it became mandatory for all Brazilian blood donors to be screened for Chagas' disease by at least two serological techniques. In 1994 the Brazilian Ministry of health launched a program to systematically evaluate the quality of serological screening for the detection of blood-transmissible diseases as performed by public blood banks. Methods: A blind panel containing positive samples for blood-transmissible disease was distributed to 57 major public blood banks in four sequential programs. Results: The ELISA test was chosen by the majority of the blood banks. There were 64 (3.7%) false-negative results, 49 produced by banks using indirect hemagglutination. Since most blood banks screened with more than one test for Chagas, only 8 samples were actually missed, of which 3 were by banks using only one test. Conclusion: Our data show a clear improvement in performance of Brazilian blood banks testing for Chagas' disease.