Hepatitis A in Swedish travellers.

The incidence of hepatitis A is very low in Sweden. It has been shown that the prevalence of antibodies to hepatitis A virus is 6.6% in individuals < 40 years of age and 1% in those < 20 years old. The number of reported cases of hepatitis A infection has declined from 628 in 1985 to approximately 250 during the last four years. The attack rate per 100,000 inhabitants has thus declined from 7.3 to approximately 3 during this period. The number of cases in travellers has been stable at approximately 140 cases per year during the period 1985-1990. About one-third of the cases are associated with travel to either Europe or Asia. Immune globulin has been widely used as prophylaxis but use has declined. Based on travel statistics and estimation of the use of immune globulin, a risk ratio was calculated for the relation between the number of travellers not receiving immune globulin and cases of registered hepatitis A infection. This risk ratio was > 50,000 for travel to the Mediterranean part of Europe, approximately 100 for travel to Africa and approximately 300 for travel to Asia.