From non-A non-B hepatitis to hepatitis C

In 1974, the existence of hepatitis serologically distinct from hepatitis A and B was recognized. They were tentatively designated non-A non-B. They accounted for 90% of post-transfusional hepatitis. During 15 years numerous studies failed to identify agent(s) responsible for these hepatitis. In 1989 the virus responsible for parenteral non-A non-B hepatitis was identified and named hepatitis C virus. Shortly after, the virus responsible for enteral non-A, non-B was also discovered (hepatitis E virus). During these 15 years, a 60% reduction of post-transfusional hepatitis was obtained both by the measures instituted to prevent AIDS transmission and by the introduction of surrogate assays (ALT levels and anti-HBc antibody).