Transmission of BSE by blood transfusion in sheep

We have shown that it is possible to transmit bovine spongiform encephalopa thy (BSE) to a sheep by transfusion with whole blood taken from another she ep during the symptom-free phase of an experimental BSE infection. BSE and variant Creutzfeldt-Jakob disease (vCJD) in human beings are caused by the same infectious agent, and the sheep-BSE experimental model has a similar p athogenesis to that of human vCJD. Although Uh blood transfusions ale leuco depleted-a possible protective measure against any risk from blood transmis sion-this report suggests that blood donated by symptom-free vCJD-infected human beings may represent a risk of spread of vCJD infection among the hum an population of the UK.