Landmark perspective: Landmarks in viral hepatitis.

Developments in viral hepatitis have been traced from Saul Krugman's distinction of two types, MS1 and MS2 (A and B), and Baruch S. Blumberg's discovery of Australia antigen. Hepatitis A has been grown in tissue culture, the structure of the virus is known, and the acute disease can be diagnosed. Knowledge of the molecular biology of the more complex hepatitis B virion has allowed the development of an effective vaccine and distinction of replicative and nonreplicative stages of infection. Integration, in the hepatocyte, of hepatitis B viral DNA into host DNA is the precursor of liver cancer. The infection of hepatitis B carriers with another infectious agent, delta, has added a new dimension to the problem. Other unidentified causes of hepatitis have been lumped together as non-A, non-B, and these remain to be defined and accurately diagnosed.