Towards a hepatitis A vaccine. A review

Hepatitis A is an acute inflammation of the liver caused by a virus (HAV) whose morphology and physical characteristics resemble members of the enterovirus group. The disease, which is characterized by fever, malaise, anorexia, nausea, abdominal discomfort and jaundice has an average incubation period of 28–30 days and is spread from person to person by the faecal-oral route. Common-vehicle outbreaks have been reported following contamination of food or water and epidemics may occur in closed communities (institutions, day-care centres) or in the general community when there is a breakdown of environmental sanitation. Many infections, especially in children, are subclinical; the case fatility rate for patients requiring hospitalization is low and long-term sequelae are unknown.