Table 1

World Health Organization defined patterns of hepatitis A endemicity2

HighDeveloping countries with poor sanitary/hygienic conditions—parts of Africa, Asia, and central and South America. Infection mostly in children and therefore usually mild or asymptomatic. Incidence of disease may reach 150/100 000 population per year. Approximately one million cases per year in these areas.
IntermediateCountries where sanitary conditions are variable—south and east Europe, parts of the Middle East. Many children escape infection, therefore clinical disease incidence may be high as infection occurs more frequently in adults.
LowCountries with good sanitary and hygienic conditions—northern and western Europe, Japan, Australia, New Zealand, United States, and Canada. Infection rates are low and disease may occur among specific risk groups such as travellers. Disease incidence of 5–10/100 000/year