Investigations on the distribution of HBs antigen subtypes.

The study was performed in 2,054 sera collected from HBsAg-positive acute viral hepatitis (AVH) patients within the first days after onset. HBsAg were subtyped by immunodiffusion (it was possible to specify the antigenic subdeterminant in 1,816 sera) and titrated by counterelectrophoresis. The results were analysed according to the territory and to the patients' sex and age. The overall ad:ay ratio was of 18:82 and zonal differences in subtype ratio were found. A marked predominance of male subjects (57%) among HBsAg-positive AVH patients was observed, especially in younger age groups. Half of the cases could be included in the age groups from 5 to 29 years. Higher ad:ay values were found at low antigen titers.