Chapter 6 - Viral infections of the liver

Abstract

This chapter discusses the clinical features, prevention, and treatment of various viral infections of the liver, such as acute viral hepatitis type A, viral hepatitis type B, viral hepatitis type C, delta hepatitis, herpes simplex hepatitis, and mosquito borne viral hepatitis. It also explains the viruses that have a high degree of hepatic trophism. Acute viral hepatitis type A is an acute inflammation of the liver with varying degrees of hepatocellular necrosis caused by the enterically transmitted hepatitis A virus (HAV), a member of the picornavirus family. The hepatitis is usually benign but severity may increase with age. There are no long-term sequelae but the disease may be relapsing. Viral hepatitis type B is caused by the hepatitis B virus (HBV), a double-stranded DNA virus of the hepadnavirus family which has unique biological properties. Unlike hepatitis A virus the host immunological response may be ineffective leading to chronic infection. Transmission of HBV occurs by the parenteral route; however, as minute quantities of blood are infective it may be blood-borne via unapparent fomites. In saliva and semen viral concentrations are 100–1000 times less than in blood but both have been shown to be infective in experimental studies. Hepatitis C virus (HCV) has been shown to cause the majority of cases of post-transfusion non-A non-B hepatitis and much sporadic, community acquired non-A non-B hepatitis in many parts of the world.