Faeco-oral transmission. Global distribution.
Incubation 4/52, can be asymptomatic in young children. Non-specific fever, malaise, possibly RUQ pain before jaundice appears, usually with rapid relief in symptoms. Up to 1% however have fulminant disease with hepatic failure.
Post exposure prophylaxis for hepatitis A with hepatitis A vaccine reduces secondary infection rate from 13% to 2.8% (NNT=18).
See also viral hepatitis.