Chronic viral hepatitis remains one of the major medical problems worldwide. Neither a cure nor eradication of this disease is in sight. The chronic disease caused by hepatitis viruses type B, C and D is a much greater problem than the acute disease caused by the same viruses or by hepatitis viruses type A and E. Chronic viral hepatitis often remains unrecognized until the patient develops decompensated liver cirrhosis or hepatocellular carcinoma. Furthermore, unrecognized chronic virus carriers are a persistent source of infection by sexual and other close contacts as well as during many medical procedures. The viruses of chronic hepatitis are very different from each other from a taxonomical point of view, but they share many common pathogenic properties and they often coinfect individuals. Six years ago Carlo De Bac, Gloria Taliani (Rome) and I undertook an effort to bring together, under the auspices of the European Society against Virus Diseases, clinicians, laboratory physicians, epidemiologists, pathologists and molecular biologists whose primary research interest is chronic viral hepatitis. The contributions from these quite divergent participants to a meeting devoted solely to chronic viral hepatitis were most stimulating and valuable. As a result of the success of the first meeting in Fiuggi (Italy), a second followed in Siena (Italy) 1990 and the recent third meeting was held in Pisa (Italy). Most of the speakers expressed interest in publishing their contributions in the form of a proceedings volume, as was done in the case of the Siena meeting.

Chronic viral hepatitis is discussed here in a multidisciplinary approach. The editors' goal was to assemble contributions from clinicians, laboratory physicians, epidemiologists, pathologists, and molecular biologists to provide a synopsis of all the important aspects of this disease. A key element in the chronic evolution of viral hepatitis is the persistent coexistence of a cytotoxic immune response and viral gene expression which is discussed in eleven articles on immune pathogenesis. The oncogenicity of hepatitis B virus at the molecular level and of hepatitis C virus at the epidemiological level is discussed in two chapters. The application of PCR for the detection of hepatitis viruses and their variants is a major topic of both practical and theoretical interest. The clinical significance of newly developed serological assays for diagnosis and prevention is discussed in depth by specialists from clinics, transfusion centers and virological laboratories. The therapy of chronic viral hepatitis is still unsatisfactory, but some slow progress is described in several articles. Furthermore, the volume has a special chapter on the often neglected topic of chronic hepatitis in childhood.