[Epidemiological studies of viral hepatitis with and without HB antigen by means of complex studies in families].

The results of an epidemiological and laboratory investigation on 242 adults and children, who had come in contact with patients suffering from viral hepatitis (in the family or outside it), showed the importance of family contact and the role of routes of transmission other than the parenteral and transfusional ones in viral hepatitis with positive HB antigen. Attention is likewise drawn to the importance of the laboratory tests (classical enzymatic tests and immunoelectrodiffusion) in the detection of epidemogenic sources, represented by the subclinical forms of infection.

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.