The modern landscape of transfusion-related iatrogenic Creutzfeldt-Jakob disease and blood screening tests.

The idea that blood in naturally occurring transmissible spongiform encephalopathies is not infectious has imploded in the face of recent transmissions from the blood of naturally occurring scrapie in sheep and of variant Creutzfeldt-Jakob disease in humans. Although donor exclusion criteria ensure that the number of any further iatrogenic cases will be small, the risk of future blood-borne disease transmissions could be entirely eliminated by a diagnostic preclinical screening test. A variety of methodological approaches to blood testing are under development, with different levels of success, but no method has yet achieved the critical goal of discriminating transmissible spongiform encephalopathy-infected from healthy uninfected humans.