ABSTRACT

Hepatitis A, B, C, D, and E viruses are the five major etiologic agents of viral hepatitis. These five different viruses infect primarily the liver and are commonly referred to as the hepatitis viruses. Several other viruses, including GB-virus type A (GBV-A), GB-virus type B (GBV-B), GB virus type C (GBV-C, also known as hepatitis G virus [HGV]), and TT-virus, have also been isolated from hepatitis patients. However, the role of these viruses in the development of hepatitis appears to be minor, if there is any.