Hepevirus (Hepatitis E Virus)

Key Points

• Hepeviruses (FA 2019 p167, MB)
  • Characteristics
    • RNA viruses
      • replicate in the cytoplasm of cells
      • Single-stranded
    • + sense
    • Linear chromosome
    • No envelope
      • Are not destroyed by the gut
    • Icosahedral capsid
  • Presentation and Key Viruses
    • Hepatitis E virus (HEV)
      • Transmission
        • Fecal-oral (esp. waterborne)
        • Enteric, epidemic (e.g. in parts of Asia, sub-Saharan Africa, Middle East, Mexico)
          • No carrier state
      • Presentation
        • Acute hepatitis
          • Occurs after short incubation period (5-6 weeks)
          • Fever, jaundice, elevated ALT and AST
          • Usually mild and self-limiting in adults
          • Fulminant hepatitis in pregnant women
            • High mortality in pregnancy
      • Diagnosis
        • Liver Biopsy
          • All viral hepatitis produce a similar histopathological pattern
          • Hepatocyte swelling (necrosis)
            • “Ballooning degeneration”, thought to be caused by ATP depletion and disruption of cytoskeleton
            • Hyperplasia may also occur due to regeneration of tissue (active cell replication) lost to viral damage
          • Monocyte infiltration
            • Occurs due to viral infection and hepatocyte necrosis
          • Councilman bodies
            • Apoptotic bodies form round pink (eosinophilic) bodies known as Councilman bodies
        • HEVAg can be detected by ELISA, or HEV RNA by RT-PCR
        • Anti-HEV antibodies may be seen in blood
      • Treatment
        • Supportive