Lognormal distribution of HBsAg strengths in an English population.
The frequency distribution of reverse passive haemagglutination titres for HBsAg in the sera of 78 positive blood donors found furing 2.5-year period closely follows a lognormal distribution curve. This lognormal distribution suggests that the total population of HBsAg-positive donors during this period was approximately 84. The modified Hepatest now in use will be expected to detect 82 of these, and to miss only 1 HBsAg-positive donor in 50,000 screening tests of Manchester blood donors.