Virology and Immunology of Hepatitis Viruses

  • Authors: Esperance Anne Kreek Schaefer, MD, MPH; Raymond T. Chung, MD (More Info)
  • Editor In Chief: Stefan Zeuzem, MD
  • Last Reviewed: 7/10/18 (What's New)

Summary

Introduction

  • Viral hepatitides are a widely disparate and heterogeneous group of viruses
    • Can be broadly categorized into enteric pathogens (hepatitis A and E) and parenteral pathogens (hepatitis B, C, and D)
    • Enteric viruses cause self-limited acute infections
    • Parental viruses may cause self-limited infections or progress to chronic liver disease

Hepatitis B Virus

    Epidemiology and Natural History
    • HBV is the most common hepatitis virus and one of the most common infections worldwide
      • Chronic HBV infection is found in an estimated 257 million individuals[WHO 2017]
    • Major sources of transmission are perinatal, close contact with infected individuals during childhood, sexual contact, and injection drug use
    • The clinical course and chronicity vary depending on the age of exposure
      • Exposure in infancy is associated with high rates of persistence
    • HBV can progress to cirrhosis, hepatocellular carcinoma, and death
    • The natural history of chronic hepatitis B can be divided into 4 distinct major clinical phases (Figure 1)[...

      Action required