Opinion of the Scientific Panel on biological hazards (BIOHAZ) on BSE risk from dissemination of brain particles in blood and carcass following stunning

Abstract

SUMMARYThe European Commission (EC) requested the European Food Safety Authority (EFSA) and its Scientific Panel on Biological Hazards for an update of the latest SSC opinion of 2002 related to the risk of dissemination of brain particles into the blood and carcass when applying certain stunning methods.The Scientific Panel on Biological Hazards concludes that brain damage caused by both penetrating and non-penetrating captive bolt stunning in cattle, as well as that caused by penetrating captive bolt stunning in sheep, can result in occurrence of Central Nervous System (CNS) tissue emboli in venous blood draining the head. Therefore, the nonpenetrating method currently used cannot be considered as an alternative method to the penetrating method. It also concluded that following penetrating captive bolt stunning, the likelihood of CNS tissue embolism is higher in sheep than in cattle. New data, based on the results of detection methods currently available, confirm the occurrence of CNS embolism following penetrating or non-penetrating stunning methods. However, methods for examination of different tissue/organs for the presence and quantification of the CNS material have not been optimised. It was also concluded that analysis of the available data can not confirm either an association, or the absence of an association, of CNS tissue embolism with a number of alternative methods, including electrical stunning method.The Scientific Panel on Biological Hazards recommends that further studies in particular on modifications of the current captive bolt stunning methods so as to prevent CNS embolism are required. Alternatively, the replacement of these methods should be investigated. In addition, also validation studies on the occurrence of stunning-associated CNS embolism conducted under commercial conditions are required. Such studies should focus on the involvement of systemic arterial circulation in the distribution of CNS emboli. Research should also focus on optimized methods for the detection and quantification of stunning-induced dissemination of CNS material to different organs/tissues and on optimal sampling methods/plans, which can provide comparable results between various studies.