Antibody against hepatitis A in seven European countries. I. Comparison of prevalence data in different age groups.

Using a solid phase radioimmunoassay, antibody to hepatitis A virus (anti-HAV) was determined in 3890 sera from populations in seven European countries. Prevalence of anti-HAV was lowest in Scandinavian countries and highest in Greece and France. Antibodies were found in 77 (13%) of 602 blood donors in Sweden, in 29 (17%) of 175 blood donors and women taking birth control pills in Norway, in 273 (39%) of 700 blood donors in Switzerland, in 262 (52%) of 505 blood donors in Holland, in 365 (55%) of 661 accident patients in West Germany, in 452 (75%) of 600 blood donors in France and in 530 (82%) of 647 persons in Greece. Prevalence of anti-HAV increased with age in all populations tested, indicating nearly total exposure to HAV in persons over 19 years of age in Greece and in persons over 39 years of age in West Germany, Holland and France. Antibody was found more frequently in rural than in urban populations in Greece and Switzerland. Calculation of the age-specific incidence of HAV infections suggests a remarkable decline in the exposure rate in the last few decades.