Viral hepatitis.

Viral hepatitis may be classified into three or more forms including type A hepatitis, type B hepatitis, and a group denoted as non-A non-B hepatitis which may represent viral hepatitis of one or more causes. The differentiation of these forms of hepatitis is primarily serologic. The development of antibody to hepatitis A virus can be detected by radioimmunoassay as well as by other test systems. The serologic diagnosis of type B hepatitis rests on the detection of hepatitis B surface antigen or on the development of antibody to hepatitis B core antigen or hepatitis B surface antigen. The serologic diagnosis of non-A non-B hepatitis is a diagnosis of exclusion for assay systems for this form of disease are not yet available.A prototype hepatitis B vaccine has been prepared and is currently undergoing clinical trials. Gamma globulin is now available that contains high titered antibody against hepatitis B virus. Normal immune globulin contains high titers directed against hepatitis A virus. Therefore, for documented exposure, effective prophylaxis is available for both of these forms of acute liver disease. The past decade has resulted in rapid advances in our understanding of the pathogenesis of acute hepatitis and its extrahepatic manifestations. However, it is clear that specific treatment for acute hepatitis and the accurate description of the etiologic agents of non-A non-B hepatitis require exploration.