The limits of test-based scrapie eradication programs in goats.

Area of Science:

• Veterinary Epidemiology
• Prion Disease Research
• Animal Health Surveillance

Background:

• Classical scrapie, a prion disease, affects small ruminants.
• Post-mortem testing programs are being considered for scrapie control.
• Effective surveillance is critical for the success of eradication policies.

Purpose of the Study:

• To evaluate the performance of post-mortem classical scrapie detection in goats.
• To estimate the efficiency of scrapie surveillance in commercial goat populations.
• To assess the viability of post-mortem testing as a sole strategy for scrapie eradication.

Main Methods:

• Determined detection performance in 8 naturally affected goat herds (n=1961).
• Analyzed performance based on age at culling.
• Utilized a Monte Carlo simulation model to estimate population-level surveillance performance.

Main Results:

• Post-mortem testing showed limited success in identifying infected herds, regardless of test numbers.
• The efficiency of surveillance was estimated using simulation modeling.
• Age at culling influenced detection performance.

Conclusions:

• Scrapie eradication programs solely reliant on post-mortem testing in goats are unlikely to succeed.
• The efficiency of scrapie surveillance in goats and sheep may be similar due to shared disease traits.
• Enhanced surveillance strategies are needed for effective scrapie control.