CONTEXT

Transmissible spongiform encephalopathies (TSE - Creutzfeldt-Jakob disease in humans, BSE, scrapie, CWD in animals) are characterized, post-mortem, by accumulation of the pathological prion protein PrPSc in brain tissue. This unconventional infectious agent is transmitted by blood transfusion, contaminated feed, food or health products.

So far, no commercially blood screening assay is available to detect prion agent in blood. Indeed, standard procedures used to detect PrPsc in tissues have failed in blood samples. Several studies have suggested that
the infectious forms circulating in blood may have different physicochemical properties from those accumulating in tissues, especially concerning their high sensitivity to proteinase K digestion.