Hepatitis A

(HAV)

• Single stranded RNA enterovirus (aka enterovirus 72)
• The most common type of viral hepatitis
• Transmitted by faecal-oral route
  • history of travel, shellfish, family contacts, homosexual practices, IV drug use
• Spread: oral-faecal route. Eg. poor contaminated food (shellfish) and water.
• Virus resistant to chlorination. Killed by boiling water for 10 mins

Symptoms

• Incubation 2-4 weeks
  • malaise
  • anorexia
  • nausea
  • right-sided abdominal pain
• 1-2 weeks later
  • jaundice
  • pale stools
  • dark urine
• ? acute liver failure
• milder in younger children than in older children/adults

Examination

• jaundice
• hepatomegaly
• splenomegaly
• tender lymphadenopathy
• transient rash

Complications

• arthritis
• vasculitis
• myocarditis
• renal failure

Investigations

• Liver Function tests
  • very high ALT, AST
• Hepatitis A specific IgM
  • can cross-react with Epstein-Barr virus serology
• ELISA of faeces for HAV antigen
  • virus present in faeces 1-2 weeks before symptoms

Treatment

• no antiviral therapy available
• supportive
• isolate for 7 days to prevent cross-infection
• notify
• Self limiting with no chronic sequelae.
• Vaccinate close members of family.

Prophylaxis

• Active vaccination with formaldehyde inactivated vaccine for people at risk (travelling, chronic liver disease, haemophilia). 1 year cover with booster providing a 10-year immunity.
• Passive vaccination with normal human immunoglobulin gives protection for 1-4 months. (Useful for persons occasionally at risk)

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