Hepatitis G Virus
Hepatitis G virus (HGV) is similar to viruses of Flaviviridae family, which includes HCV. The flavivirus-like isolates were first demonstrated in Tamarin monkeys inoculated with blood from a surgeon with acute hepatitis in 1995. A similar virus was isolated from another patient during the same year. These viral isolates were designated GB viruses A, B, and C. A similar virus resembling GBVC (GB virus C) was isolated from a patient with chronic hepatitis in 1996. Now the virus has been designated as HGV.
Hepatitis G virus is an RNA virus and its genome codes for 2900 amino acids. The virus shows 95% homology at the amino acid level with GB virus and GBVC, a previously described virus. HGV has 20% homology with HCV.
Hepatitis G virus is a blood-borne virus, which is transmitted by transfusion of contaminated blood or blood products. HGV coinfection is observed in 6% of chronic HBV infection and in 10% of chronic HCV infection. Although HGV RNA has been demonstrated in patients with acute, chronic, and fulminant hepatitis, patients with multiple transfusions and hemodialy-sis, blood donors, and intravenous drug addicts, its role in the pathogenesis of hepatitis is yet to be elucidated. Therefore, whether or not HGV is actually a pathogen in humans, still remains to be clarified.