Viral Hepatitis: 1985 Update

During the past two decades extraordinary advances in hepatitis research have clarified the etiology and natural history of the disease. At least four types of hepatitis have been identified: A, B, D (delta), and non-A, non-B. Hepatitis A virus (HAV), hepatitis B virus (HBV), and hepatitis D virus (HDV) have been characterized. Serologic tests have been developed to detect the antigens and antibodies associated with these three hepatitis infections. As of the present time, the non-A, non-B viral agents have not been identified. Therefore, non-A, non-B hepatitis is diagnosed by excluding other viral causes of hepatitis, such as hepatitis A virus, hepatitis B virus, Epstein-Barr virus (EBV), cytomegalovirus (CMV), and others. A recent report indicating that non-A, non-B hepatitis may be caused by a retrovirus, if confirmed, may provide a specific marker of this infection. The course of viral hepatitis is variable; it may be an asymptomatic, anteric infection, or it may be an acute illness characterized by fever, malaise, anorexia, nausea, abdominal pain, and jaundice. Most patients recover completely, but occasionally the infection may be complicated by chronic hepatitis, cirrhosis, and, occasionally, by a fulminant fatal outcome. This review will be devoted predominantly to a discussion of the diagnostic and prophylactic aspects of hepatitis A and hepatitis B viral infections.