Significance of SEN virus in post-transfusion hepatitis. Bedeutung von SEN-Viren für die Posttransfusionshepatitis

Abstract

Abstract Five hepatitis viruses (A-E) cause more than 80% of cases of viral hepatitis. However, the fact that nearly 20% of individuals with acute hepatitis test negative for all known hepatitis viruses, as do up to 10% of patients with transfusion-associated hepatitis, suggests the existence of other viral hepatitis agents. Hepatitis G virus (HGV) and TT virus (TTV) were originally proposed as potential causative agents. The SEN virus (SENV) belongs to a recently discovered group of DNA viruses whose members (SENV D and SENV H) are associated with post-transfusion hepatitis. Eight different strains of SENV have been identified and provisionally classified as members of the Circoviridae family, a group of small, single-stranded, non-enveloped circular DNA viruses which includes, in addition to SENV, the TT virus (TTV), TUS01, SANBAN, PMV, and YONBAN viruses. SENV is a single-stranded circular, non-enveloped DNA virus of ~3.600 to ~3.900 nucleotides with at least three open reading frames (ORFs). The prevalence in different populations shows great variability with marked differences between different countries and groups. Although parenteral transmission is very likely, other routes of transmission are not excluded. Mother-to-infant transmission has been demonstrated. Data on other acute and chronic liver diseases are sparse. Further studies are needed to define the pathogenesis and clinical importance of SENV infection.