The risk of transmitting prion disease by blood or plasma products

Various experimental studies have shown infectivity in blood in relation to bovine spongiform encephalitis (BSE) and variant Creutzfeldt–Jakob disease (vCJD). Human to human transmission vCJD infection has been reported via transfusion of non-leukocyte-reduced red cells and, probably, via factor VIII concentrates. A number of precautionary measures are in place but uncertainties remain, especially concerning the number of BSE-infected people in the population. Additional measures such as prion filtration need consideration.