DEVELOPMENTS IN VIRAL-HEPATITIS DURING 1995

The discovery of hepatitis C virus (HCV) in 1987 and the subsequent de velopment of diagnostic tests has accounted for the majority of cases of viral hepatitis throughout the world. However, a significant number of cases cannot be assigned to any of the viral hepatitis groups (A - E). During 1995 two companies reported the identification of novel he patitis viruses known as GBV-B and hepatitis G virus (HGV), which were found to be responsible for a large proportion of the remaining undia gnosed cases. Sequence analysis of these two viruses revealed them to be isolates of the same virus and, moreover, to be close homologues of HCV. The clinical significance of these new viruses is currently uncl ear, but preliminary epidemiologic evidence suggests they are often fo und as co-infections with HCV. The close similarity of these viruses t o HCV and the fact that related viruses have also been identified whic h infect small primates, suggests that they may be useful as surrogate agents for the identification of novel therapeutic agents against HCV . Current therapeutic agents against HCV are still disappointing altho ugh more encouraging data have been reported on long-term combination therapy with interferon-ce and ribavirin. Studies have continued aimed towards developing assays for biochemical functions specified by vira l proteins and these are still mainly focused on the multi-functional NS3 protein.