ABSTRACT
References 751
Human prion diseases, also known as the transmissible spongiform encephalopathies, have been traditionally classified into Creutzfeldt-Jakob disease (CJD), Gerstmann-Stra¨ussler syndrome (GSS) (also known as Gerstmann-Stra¨ussler-Scheinker disease) and kuru. Remarkable attention has been focused on these rare diseases because of the unique biology of the transmissible agent or prion, and also because of the epizootic of bovine spongiform encephalopathy (BSE) and the evidence that BSE prions have infected humans, causing the new human prion disease known as variant CJD (vCJD). Human prion infection is associated with long, clinically silent, incubation periods which may span over half a century (Collinge et al., 2006), and while the numbers of recognized cases of vCJD have been relatively small, uncertainty remains as to the number of infected individuals in the United Kingdom and other BSEaffected countries, the eventual epidemic size of BSE-related human prion disease, and the risks of its secondary transmission from such asymptomatic carriers via medical and surgical procedures. Such secondary transmission of vCJD prion infection by blood transfusion is well documented and transmission by blood products may have occurred (Wroe et al., 2006; Peden et al., 2010).
