Prevalence of hepatitis A antibodies in a normal population and some selected groups of patients in Norway.

The prevalence of hepatitis A virus antibodies was tested by radioimmunoassay in Norway in healthy blood donors, in patients without clinical signs of liver diseases and in two selected groups of patients. The presence of hepatitis A antibodies was highly age-dependent in 625 normal persons. A major reduction occurred from 50 per cent or more in those born before 1938 to 10 per cent or less among those born after 1943. The decline of hepatitis A antibody prevalence was correlated to the history of infectious hepatitis epidemics in the entire country during World War II. The prevalence was not different from controls in a group of patients with various liver disorders. Hepatitis A antibodies were more prevalent in males than in females in blood donors, patients with chronic liver disorders and their controls. Hepatitis A antibodies were frequently present in prison inmates; their presence was associated with the presence of antibodies against hepatitis B virus and with anamnestic data on drug addiction.