The Risk of Prion Zoonoses

摘要

Prions are lethal infectious pathogens that cause neurodegenerative diseases in humans and animals (i). They can pass from one species to another but with greater difficulty than transmission within the same species because of the so-called species barrier effect. Such barriers protect humans from developing prion disease after dietary or other exposure to animal reservoirs of infection. These include endemic scrapie of sheep and goats, chronic wasting disease (CWD) of deer and elk, and bovine spongiform encephalopathy (BSE) or "mad cow disease" (/). On page 472 of this issue, Beringue et al. (2) show that in transgenic mice expressing ovine or human prion protein (PrP), lymphoid tissue is more susceptible to cross-species transmis- sion than neural tissue (brain), which may prompt a reevaluation of the effectiveness of species barriers.