Hepatitis A
Epidemiology
- 50% acquired during travels abroad
Etiology
- Contaminated water and food (e.g., raw shellfish)
Pathophysiology
- HAV is not cytopathic in itself; research suggests that liver damage is caused by cellular immunity (especially CD8+ T cells).
Clinical features
Tip
- Unlike hepatitis B or C, HAV infection is a self-limiting disease that is not associated with an asymptomatic viral carrier state and does not progress to chronic hepatitis, cirrhosis, or hepatocellular carcinoma.
- HAV only has acute phase, HCV only has chronic phase
In children age < 6, HAV infection is most often (>80%) silent or subclinical . Clinical disease is typically more severe (70% of symptomatic patients with jaundice) in adults (some of whom develop an aversion to smoking, for unclear reasons)
- Incubation period: 2–6 weeks
- Phases of acute viral hepatitis
- Prodromal phase: 1–2 weeks
- Right upper quadrant pain, tender hepatomegaly
- Fever, malaise
- Anorexia, nausea, vomiting
- Icteric phase: ∼ 2 weeks
- Jaundice
- Dark urine and pale stools
- Pruritus
- Resolution of symptoms
- Prodromal phase: 1–2 weeks
Diagnostics
- Liver biopsy: not routinely indicated
- Periportal inflammation (mononuclear cell infiltration)
- Hepatocyte swelling
- Ballooning degeneration
- Bridging necrosis
- Councilman bodies (apoptotic hepatocytes)