Human prion diseases are rare, but their characteristics are well defined with animal models that replicate the biological features with some fidelity. The pathogenesis is driven by misfolding of a normal host-encoded protein and self-templated accumulation of the abnormal disease-associated protein. The diseases are uniformly fatal and there is no effective treatment. Rarely prion disease has been transmitted iatrogenically, mainly through treatment with human pituitary derived hormones and human dura mater grafts and in variant Creutzfeldt-Jakob disease by blood transfusion.
There is increasing evidence from both observational studies and animal models that other neurodegenerative diseases may share a pathogenic mechanism similar to prion diseases. An important question for public health is whether there is potential for accidental transmission of these disorders through prior medical or surgical treatment. Recent evidence suggests that both a-beta and tau protein may accumulate prematurely following growth hormone treatment or prior neurosurgery, but transmission of actual disease has not been established.