Donor self-exclusion patterns and human immunodeficiency virus antibody test results over a twelve-month period.

Donor behavior in completing a pre-donation confidential self-exclusion form, which identified blood donors at high-risk of AIDS exposure, was evaluated. The form was completed by all donors during a 12 month period beginning in September, 1985. 188,824 units of blood were collected from 123,608 donors. On the first donation occasion 901 donors (0.73%) laboratory (LAB) designated, 224 (0.18%) did not complete the form correctly, and the remaining 122,483 transfusion (TRAN) designated. A greater proportion of LAB donors were men, under the age of 30 and had not donated in the previous two years than TRAN designated donors. Confirmed reactive anti-HIV, Western blot positive (WB+) results were greater in LAB than TRAN donors (1.664% vs 0.014%) on the first donation occasion. There were 43,982 donors who returned to donate on at least one other occasion. Of these, 43,778 designated TRAN initially, and only 217 (0.49%) changed their designation to LAB on any subsequent donation event. In contrast, of the 204 donors who designated LAB initially, 134 (65.6%) changed to TRAN on at least one other occasion. A variety of designation combinations from LAB to TRAN and back to LAB occurred. Thus, donors who initially LAB designated were more likely to change their designation on at least one other occasion than those who initially designated for TRAN. Of two donors who became anti-HIV WB positive on the second donation, one of these LAB designated on both occasions, was negative for anti-HIV by enzyme-linked immunoassay (EIA-) on the first donation but converted to EIA+, WB+ on the second.(ABSTRACT TRUNCATED AT 250 WORDS)