Background: Theoretical concerns of possible variant CJD (vCJD) transmission by transfusion have led to deferral of US donors potentially exposed to the bovine spongiform encephalopathy agent. Although the efficacy of these policies is unknown, impact on blood collections has been substantial. Under the precautionary principle, deferral of donors consuming bovine (or other mam-malian) brains, possibly contaminated with the vCJD agent, might be considered. Blood donors were surveyed to determine lifetime mammalian brain consumption.
Study design and methods: The Retrovirus Epidemiology Donor Study (REDS) conducted an anonymous mail survey of 92,581 donors from eight US blood centers.
Results: Responses were received from 52,650 donors (57%). Of these, 6.4 percent reported lifetime brain consumption; bovine (3.6%) and hog brains (1.7%) were the most common. Bovine brain consumption varied fourfold by center (1.7-7.0%) and was highest among male (4.5%), older (age 55+, 6.5%), foreign-born (9.2%), Asian (7.2%), and Hispanic (8.6%) donors. Among bovine brain consumers, 67 percent engaged in the practice 4 times or less, 79 percent were repeat donors, and 61 percent reported giving at least 11 donations in the past 10 years.
Conclusion: Following the precautionary principle, further steps to reduce the theoretical vCJD risk could include deferring donors who eat bovine (or other mammalian) brains. The impact of such a policy would not be trivial, especially in areas with older, foreign-born, Asian, or Hispanic donors. Cautious implementation and periodic evaluation of deferral policies is warranted.