Clinical Virology has two major sections. The first addresses infections and syndromes related to particular organ systems, as well as the fundamentals of modern medical virology, including immune responses and vaccinology, diagnostics, antivirals, and the nascent field of gene therapy.The second provides agent-specific chapters that detail the virology, epidemiology, pathogenesis, clinical manifestations, laboratory diagnosis, and prevention and treatment of important viral pathogens. In a multiauthored text like Clinical Virology, the selection of authors is key. The senior authors for individual chapters were chosen because of their internationally recognized expertise and active involvement in their respective fields. In addition, common templates for the syndrome-specific and separately for the agent-specific chapters allow the reader to readily access material. Since publication of the second edition in 2002, all of the chapters have been extensively revised to incorporate new information and relevant citations. In addition, the rapidly expanding field of antiviral drugs demanded dividing the subject into two chapters.