Emerging viral infections relevant to transfusion medicine

The development of new technologies leads to the discovery of new viruses. For each of these new infectious agents relevance to transfusion needs to b e assessed. The questions to be answered are transmissibility by transfusio n, pathogenicity, prevalence in blood donors, persistence and the availabil ity of screening assays. Since 1995, three new viruses have been identified and extensively studied. GB virus-C/hepatitis G virus (GBV-C/HGV), a relat ively rare virus with some homology with and epidemiological features of HC V, was thought to be related to post-transfusion hepatitis but was proven t o be unrelated to hepatitis and is still in search of a disease. Human herp es virus-8 (HHV-8) is a major factor in the pathogenesis of Kaposi's sarcom a and other tumours related to immunodeficiency. HHV-8 transmission by orga n transplantation, but not by transfusion, has been demonstrated. The TT vi rus (TTV) is a ubiquitous virus infecting a very high proportion of humans in infancy. No clinical symptoms or pathogenicity is attached to TTV. To da te, none of the emerging viruses have been proven relevant to transfusion. (C) 2000 Harcourt Publishers Ltd.