Animal prion diseases: the risks to human health

Area of Science:

• Veterinary Medicine
• Neuroscience
• Public Health

Background:

• Transmissible spongiform encephalopathies (TSEs) are animal prion diseases including scrapie, chronic wasting disease (CWD), and bovine spongiform encephalopathy (BSE).
• Historically, zoonotic potential was considered low due to species transmission barriers.
• The emergence of variant Creutzfeldt-Jakob disease (vCJD) linked to C-BSE highlighted the zoonotic risk.

Purpose of the Study:

• To assess the zoonotic potential of various animal prion diseases.
• To understand the implications of underestimation of prion disease prevalence in ruminants.
• To emphasize the need for continued surveillance and risk mitigation.

Main Methods:

• Review of epidemiological data and surveillance programs in the EU.
• Analysis of transmission experiments in nonhuman primates and transgenic mice.
• Characterization of prion strain diversity and zoonotic abilities.

Main Results:

• EU surveillance revealed underestimated prevalence of scrapie and C-BSE.
• New atypical TSE forms and CWD were identified in Europe.
• Transmission studies indicate zoonotic potential for classical scrapie, L-BSE, and CWD.

Conclusions:

• Certain animal prion diseases, including classical scrapie, L-BSE, and CWD, may infect humans.
• Uncertainties regarding prion disease origins and relationships necessitate caution.
• Continued surveillance and measures to limit human exposure are vital.