At a meeting of the CBLA Central Committee on 27 November 1983, the proportion of donations which might be excluded by a positive test was indicated by the percentage of samples obtained in Bristol which tested positive, which was 0.75% (75 cases out of 10,000 tests). However, it emerged that 48 out of these 75 were prisoners, so it was decided that another 10,000 donations excluding those from prisoners would be tested.