This episode examines the hepatitis viruses, a group of unrelated viruses unified by their shared target: the liver. Drawing from Murray’s Chapter 55, it explores how different genomic strategies converge on hepatocellular injury.
The episode is organised by virus:
Hepatitis A virus (HAV) - non-enveloped RNA virus, faecal–oral transmission, acute self-limited disease
Hepatitis B virus (HBV) - partially double-stranded DNA virus with reverse transcription step, blood and sexual transmission, chronic infection potential
Hepatitis C virus (HCV) - enveloped RNA virus, high chronicity rate
Hepatitis D virus (HDV) - defective RNA virus requiring HBV co-infection
Hepatitis E virus (HEV) - faecal–oral transmission, severe disease in pregnancy
Pathogenesis involves immune-mediated hepatocyte injury rather than direct cytolysis alone. Chronic infection may lead to cirrhosis and hepatocellular carcinoma.
Conceptually, hepatitis viruses illustrate that organ tropism transcends viral taxonomy. Clinically, vaccination, antiviral therapy, and screening strategies are central to prevention and long-term management.
Key Takeaways
Hepatitis viruses are genetically diverse but hepatotropic
HAV and HEV are primarily faecal–oral
HBV and HCV may become chronic
Chronic infection increases cancer risk
Vaccination is available for HAV and HBV
