GB hepatitis viruses

In Britain no agent can be identified in 50% of cases of acute liver failure of apparently viral cause. Search therefore continues for new hepatitis viruses

Flavivirus-like agents have been isolated including GB viruses, GB-A, GB-B and GB-C.

Hepatitis G virus (HGV) (also called hepatitis GB virus-C) is a single-stranded, positive-sense RNA virus that is, like hepatitis C virus (HCV), a member of the Flaviviridae family. In common with both HBV and HCV, it is hepatotropic and has a global distribution

• HGV genome is comprised of approximately 9400 nucleotides, and codes for a single large polyprotein
• exposure to blood products is a recognized route of acquisition of HGV infection in humans, and the virus is often detectable in the serum of patients who have received multiple blood transfusions, as well as in intravenous drug abusers
• prevalence of HGV viremia in chronic non-A-E liver disease of 3-15% is not greater than that of persistent HGV RNA in nonviral chronic liver disease. Accordingly, conclusive evidence that HGV causes liver disease and hence qualifies to be a hepatitis virus is lacking

Reference:

• Kew MC. Hepatitis viruses (other than hepatitis B and C viruses) as causes of hepatocellular carcinoma: an update. Kew MC.J Viral Hepat. 2013 Mar;20(3):149-57.