ABSTRACT
Prion diseases or transmissible spongiform encephalopathies are the most feared
and fulminant of the dementias. Often rapidly fatal and without effective therapy,
the disorders are also transmissible by exposure to infectious tissues or body
fluids, raising major public health concerns. The prion diseases comprise sporadic,
inherited, and iatrogenic subtypes (for reviews see Refs. 1-4) and include
Creutzfeldt-Jakob disease (CJD), the most common of the human prion diseases,
and animal diseases, such as scrapie of sheep and goats, and bovine spongiform
encephalopathy (BSE or mad cow disease) (reviewed in 5). Scrapie is endemic in
many countries and has been recognized for over 200 years (reviewed in 6). Other
prion disorders, such as BSE, variant CJD, and the so-called exotic ungulate
encephalopathies have only recently emerged as disease entities. Other rarer
human prion diseases include Kuru, which is confined to the Fore tribe in the
highlands of New Guinea, Gerstmann-Straussler-Scheinker (GSS) disease, and
fatal familial (FFI) and sporadic fatal insomnia (FI) (Table 1).
