Viral hepatitis: expanding the alphabet

Progress in understanding viral hepatitis has occurred at a rapid pace during the last 10 years; this has led directly to improvements in prevention, detection, and treatment. In previous reviews of viral hepatitis, only two forms of infectious hepatitis, hepatitis A and B, were recognized, and other unrecognized or uncharacterized agents were classified as "non-A, non-B." Currently, many more letters of the alphabet are required to designate the growing number of viral agents discovered through the application of the techniques of epidemiology and molecular virology. Furthermore, understanding of these viruses on the molecular level has led to the discovery of multiple subsets of these agents. This expansion of knowledge has immediate implications for bedside management, including the use of polymerase chain assays for diagnosis and management of chronic viral hepatitis, potent therapeutic antiviral drugs, and new vaccination strategies. In this chapter, we discuss these recent advances in the detection and management of viral hepatitis in children.