Abstract
The European Commission requested the assessment of the capacity of the surveillance provisions of the World Organization for Animal Health (WOAH) to detect bovine spongiform encephalopathy (BSE) cases (C-, H- and L-type) in the European Union (EU) and to propose if any current EU surveillance provisions should be kept. The WOAH provisions stipulate that BSE surveillance should target animals on the BSE clinical spectrum and require the implementation of standardised clinical protocols for selecting animals for testing. Based on expert judgement of retrospective clinical data, between 5% and 49% of the 55 BSE cases detected in the EU & UK since 2015 would have been selected for testing by the WOAH surveillance. Assuming the current EU surveillance, a back-calculation model predicted a very low number of BSE cases detected for the period 2025-2029: 0.0196 for C-BSE, 10.94 for H-BSE and 9.13 for L-BSE. As no classical BSE (C-BSE) cases are expected, the application of the WOAH provisions would primarily impact the detection of atypical BSE (H-BSE and L-BSE), with an estimated detection over the next 5 years of between zero and five H-BSE cases and between zero and four L-BSE cases. Supplementing the WOAH provisions with systematic testing of fallen stock (with or without emergency slaughter) with increased age threshold of 60 or 72 months would achieve a detection capability close to current EU levels. This approach would enable the documentation of the effectiveness of BSE control measures, provide scientific assurance that the decline in C-BSE is sustained and allow atypical BSE trends to be monitored reliably while maintaining the sensitivity required to detect any re-emergence of C-BSE. Finally, this would contribute to risk mitigation by triggering immediate statutory control measures when cases are detected. Modifications of EU surveillance requirements should consider any potential adjustments to other available BSE control measures.