USMLE

Hepatitis A Virus (HAV)

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Viruses - RNA Viruses
  1. HIV: Microbiology and Characteristics
  2. HIV: Clinical Course
  3. Reovirus
  4. Picornavirus Overview
  5. Poliovirus
  6. Echovirus
  7. Rhinovirus
  8. Coxsackievirus
  9. Hepatitis A Virus (HAV)
  10. Hepevirus (Hepatitis E Virus)
  11. Calicivirus
  12. Flavivirus
  13. Hepatitis C Virus (HCV)
  14. Yellow Fever Virus
  15. Dengue Virus
  16. St. Louis Encephalitis and West Nile Virus
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  24. Respiratory Syncytial Virus (RSV)
  25. Parainfluenza Virus (Croup)
  26. Measles
  27. Mumps
  28. Rhabdovirus
  29. Filovirus
  30. Arenavirus
  31. Bunyavirus
  32. Deltavirus

Key Points

  • Hepatitis A virus (HAV)
    • Transmission
      • Fecal oral
        • Occurs in crowded areas with poor sanitation (travelers, daycare)
          • Think: standard pattern for a lot of fecal-oral infections
        • Undercooked contaminated shellfish most commonly implicated in US
    • Presentation
      • Acute Hepatitis
        • Occurs after short incubation period (~30 days)
        • Fever, jaundice, elevated ALT and AST, nausea/vomiting, abdominal pain
        • Aversion to smoking may be observed
        • Usually self-limiting in adults and asymptomatic in children
          • Usually resolves completely within 2 months
          • No carrier state
        • Good prognosis → no HCC risk
    • Diagnosis
      • Anti-HAV IgM
        • indicates acute infection
        • RT-PCR of HAV RNA also used
      • Anti-HAV IgG
        • indicates recovery/immunity
        • Due to prior HAV infection and/or vaccination
      • 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
    • Treatment
      • None; Usually self-limiting
    • Vaccination
      • killed (inactivated) vaccine