Hepatitis B antigenemia among blood donors: the changing scene.

For the period May 1973 to August 1974 inclusive, the mean prevalence of hepatitis B antigenemia (HBsAg) in all Canadian provinces (per 100,000 population) was, for "first-time" donors, 242 and, for "repeat" donors, 77. A modification of counterimmunoelectrophoresis was used in all 16 regional transfusion centres. The findings confirm the previously noted high prevalence for the Province of Québec and the continuing relatively high prevalence for Canada. The prevalence of HBsAg among donors could be lessened by institution of the following measures: development of a more effective technique for the screening of hepatitis carriers, study of nonparenterally transmitted hepatitis, better reporting of post-transfusion hepatitis, and greater discrimination in prescribing blood and blood components.