Objectives: To analyze the changes in the proportion of blood units discarded from 1991 through 2001 at the Pro-Blood Foundation/Blood Center of São Paulo (Fundação Pró-Sangue/Hemocentro de São Paulo), which is the largest blood bank in Latin America, and to determine the prevalence of infectious diseases among donors at the Blood Center in November 2001.
Methods: We compiled data concerning the discarding of blood units due to the presence of serological markers for communicable diseases at the Blood Center during the period from 1991 through 2001. To determine the prevalence of infectious diseases, 9 942 screened samples were analyzed in November 2001; all reactive samples underwent confirmatory tests.
Results: Over the study period there was a significant decrease in the percentage of units discarded, from 20% in 1991 to 9% in 2001. In November 2001 the prevalence of infectious diseases among donors was: 0.04% for human immunodeficiency virus (HIV), 0.21% for hepatitis C virus (HCV), 0.06% for human T-lymphotropic virus (HTLV), 0.14% for Chagas' disease, and 1.10% for syphilis. For hepatitis B virus, the prevalences found were: 0.14% for anti-HBc and HBsAg, 1.68% for anti-HBc and anti-HBs, and 1.67% for isolated anti-HBc.
Conclusions: The decrease in the discarding of blood units and in infectious diseases among donors at the Blood Center of São Paulo reflects the increase in the Center's percentage of repeat donors.