Update on chronic wasting disease (CWD) III

Area of Science:

• Veterinary Medicine
• Prion Diseases
• Food Safety

Background:

• Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy affecting cervids.
• Concerns exist regarding CWD strain variations between North America (NA) and Europe, and potential zoonotic implications.
• The European Food Safety Authority (EFSA) was requested to assess the current knowledge on CWD.

Purpose of the Study:

• To revise knowledge on CWD strain differences between NA and Europe, and within Europe.
• To review new evidence on the zoonotic potential of CWD.
• To identify risk factors for CWD spread in the EU and recommend risk mitigation strategies.

Main Methods:

• Review of existing scientific literature and data on CWD isolates and surveillance programs.
• Comparative analysis of CWD strains from NA and Europe.
• Assessment of available data on zoonotic potential and risk factors.

Main Results:

• Preliminary data suggest differences between European and NA CWD strains, with evidence of strain diversity in European cervids.
• Current data are insufficient to conclude on the implications of strain diversity on CWD transmissibility, pathogenesis, or prevalence.
• Zoonotic potential of CWD isolates from both continents cannot be determined; human risk via meat consumption is not directly assessable but exposure can occur.
• Risk factors for CWD spread are linked to infectivity accumulation in tissues and animal co-localization.

Conclusions:

• Further characterization of European CWD isolates is needed.
• The zoonotic potential of CWD remains unknown, requiring measures to minimize human exposure.
• Comprehensive risk factor assessment is crucial for managing CWD spread in the EU.