Blood infectivity in transmissible spongiform encephalopathies

Blood infectivity in transmissible spongiform encephalopathies (TSE) is reviewed with special emphasis on transmission by blood transfusion in human beings. It is concluded that transmission by transfusion seems biologically plausible as regards variant Creutzfeld-Jakob Disease (vCJD), albeit present knowledge suggests that it is extremely uncommon. Precautionary measures against the putative risk of vCJD transmission by blood transfusion are discussed.