For professionals:

Viral hepatitis F (a variant of HBV ?):

• After the discovery of hepatitis virus A, B, C, D, and E, a few viral hepatitis cases, both post-transfusion and sporadic, which are failed to be ascribed to A ~ E, were observed.

• In 1991 ~ 1992, investigators in Japan reported the discovery of a new hepatitis virus and called it as hepatitis virus F, but failed to be substantiated in the subsequent research.

• In 1993, Uchida of Japan reported by PCR study that the so-called hepatitis virus F might be a mutant of HBV, just could not be verified by commercially available reagents because of the defect pre-C gene, mutation of core gene and S gene, which come to be HBsAg (-) and anti-HBc (-) in serological tests. (Uchida T: Microbiol Immunol 37: 425 ~ 439, 1993; J Hepatol 18: 369 ~ 372, 1993)

• In 1994, Deka reported an isolation of a virus named HFV (Hepatitis French[origin] Virus) on intravenous innoculation of stool extract from sporadic non-A, non-B hepatitis, in New Delhi, India,however, no follow-up report was noted. (Deka N; et al.:J. Virol; 68:7810~5, 1994)

Viral hepatitis G: (HGBV-C/HGV)

• Non-A ~ E viral hepatitis.

• 1995: Simons (Abbott) identified new novel virus termed GBV-C.

• 1996: Linnen (Genelab) identified another novel virus termed HGV.

• 1996: GBV-C and HGV are identified to have the same/or very similar structure and contain two flavivirus sequences related to, but far distinct from the HCV.

• Suggested better termed HGBV-C/HGV for the time being.

• It is still contoversial if HGV will be the cause of acute, fulminant, and chronic hepatitis.

• HGBV-C/HGV has also been identified in Taiwan.