Hepatitis B antigen (HBAg) in the Republic of Ireland: Distribution of ad and ay subtypes

Summary  EIGHTY-ONE sera, positive for hepatitis B antigen (HBAg), comprising 40 patients with hepatitis, 36 blood donors and carriers and five drug addicts, were subtyped as eitherad oray using a semi-micro immunodiffusion test. Antibodies toa, d andy determinants were shown to occur in serum from a haemophiliac and were used to prepare specific antisera. Blood donors, carriers and acute hepatitis cases were predominantly of thead subtype while drug addicts were allay. There was a significantly uneven distribution of the subtypes among age groups, theay subtype predominating in those under 30, and it is thought that this could be accounted for by the increased social mixing among the younger age groups. Subtypes were evenly distributed between male and female.