Prions: Health scare and biological challenge

Although human prion diseases are rare, the incidence of 'new variant' Creu tzfeldt-Jakob disease in the United Kingdom is increasing exponentially. Gi ven that this disease is probably the result of infection with bovine prion s, understanding how prions replicate - and how to counteract their action - has become a central issue for public health. What are the links between the bovine and human prion diseases, and how do prions reach and damage the central nervous system?