Viral hepatitis: a 1994 interim report.

A variety of viruses cause many of the disorders that are recognized as acute and chronic liver diseases. Remarkable scientific advances achieved during the past two decades have lead to readily available accurate diagnostic tests for hepatitis viruses designated A through E. Effective vaccines have been developed to prevent hepatitis B and, more recently, hepatitis A. Heightened understanding of the pathogenesis of chronic hepatitis caused by hepatitis B and C suggests several promising therapeutic approaches. Interferon is the sole drug yet proven to be effective in the treatment of some patients with chronic hepatitis B and C. Newer antiviral agents that will be used alone or in combination are under development.