AN UBIQUITOUS VIRUS: The family of hepatitis viruses now has a new member discovered in 1997 by a Japanese team. The TTV (transmitted transfusion virus) is a small ubiquitous DNA virus probably largely distributed throughout the world. Prevalence in blood donors is about 2 to 10%. TRANSMISSION AND PERSISTENCE: TTV is generally transmitted via the parenteral route but can probably be transmitted via orofecal and matemo-fetal routes. The natural history of TTV has been studied in retrospective studies, particularly in hemophiliacs. After a post-transfusional peak, the virus appears to persist for long periods in the organism without causing liver damage nor any change in transaminase levels.
Pathogenicity: Although no proof is yet available, the TTV does probably not have any intrinsic pathogenic power. It would rather be a ìsurrogate virusî transmitted at the same time as another virus yet to be discovered and which causes the rare cases of non A-non-G post-transfusional hepatitis.