HEPATITIS-A IMMUNITY IN THE SWEDISH POPULATION - A STUDY OF THE PREVALENCE OF MARKERS IN THE SWEDISH POPULATION

After a 20-year interval, the prevalence of seroimmunity to Hepatitis A (HA) was again investigated in a statistical sample of the adult Swe dish population. Sera from 3382 of the 4800 originally selected person s were tested. The prevalence of antibodies to HA had not changed sinc e the 1960s when only the Scandinavian population was considered. In t he oldest population born at the beginning of this century, the presen ce of antibodies amounted to 69%. It gradually declined to 6% in those born in the 1940s. In the population born after 1950, the percentage of seropositive individuals was only 2%. A slightly higher prevalence was seen in the big cities, compared with the rural areas (13% vs 9%). Persons of non-Scandinavian origin showed a different pattern, Those from other European countries showed a prevalence of about 70% in all the age-groups investigated. Among the young adults of Arabic or Asiat ic origin, the figure was >90%. The conclusion is that the native Swed ish population has a low natural exposure to HA, which has not changed during the last 20 years. Prophylaxis before going to countries where the disease is endemic is strongly recommended.