Standards and Quality Analytical Team, Department of Health, Wellington House, 133-155 Waterloo Road, London SE1 8UG

Abstract

If a recipient of donated blood develops a disease that might have come from the transfusion, what are the implications for the donors concerned? This is a question of particular concern if the recipient develops variant CJD. There is as yet no test available to determine whether someone is carrying the infection without yet showing symptoms - a state that may last for decades. Nor is there any way of reliably eliminating the infective agent from blood or from surgical instruments used on an infective patient. If the recipient's infection did come from a blood donation, that donor might unknowingly infect others, either through further donations of blood or tissues, or through undergoing certain forms of surgery — e.g. neurosurgery. On the other hand, the recipient may have been infected by some other route, with no implications for anyone who donated blood to them. Responses to incidents of this type face a difficult balance between the need to protect public health (by reducing any risk of further infection) and avoiding needless alarm and distress to individuals. Using a simple Bayesian model, OR analysis has helped assess the implied risk to donors in such situations, and has guided decisions on how such incidents should be handled.