Heim D, Wilesmith J W
Swiss Federal Veterinary Office, Liebefeld.
Arch Virol Suppl. 2000(16):127-33. doi: 10.1007/978-3-7091-6308-5_11.
The current method used to identify suspect BSE cases is based on reporting cattle displaying clinical signs compatible with BSE. The reporting of such cases is dependent on the ability of farmers and veterinarians to recognise the disease symptoms and on the willingness to report such cases. Furthermore, it depends on the stage of the disease, because early clinical signs of BSE are not always typical. Histology and immunohistochemistry are established and reliable to confirm BSE in cattle, but the procedure is cumbersome, time consuming and therefore not suited for mass testing of animals. A targeted surveillance system using the Prionics-Western-Blot Test was initiated in Switzerland in 1999. Prionics-positive results are confirmed by histology or immunohistochemistry by the BSE-reference laboratory. This surveillance scheme has confirmed fallen stock and cows subjected to emergency slaughter as the major risk groups. Currently all cattle from these two categories are tested. As a further measure a random sample of cows from regular slaughtering is tested. This enables to determine the BSE status independent of the inaccuracies of a clinical case reporting system. This approach may be helpful to reliably assess the BSE situation in countries with low incidence in order to verify their BSE status and in countries which want to prove their BSE-free status.
当前用于识别可疑疯牛病病例的方法是基于报告出现与疯牛病相符临床症状的牛。此类病例的报告取决于农民和兽医识别疾病症状的能力以及报告此类病例的意愿。此外，这还取决于疾病的阶段，因为疯牛病的早期临床症状并不总是典型的。组织学和免疫组织化学方法在确诊牛的疯牛病方面已确立且可靠，但该程序繁琐、耗时，因此不适合对动物进行大规模检测。瑞士于1999年启动了一项使用普瑞奥尼克斯免疫印迹法的针对性监测系统。普瑞奥尼克斯检测呈阳性的结果由疯牛病参考实验室通过组织学或免疫组织化学方法进行确认。该监测方案已证实淘汰畜和接受紧急屠宰的奶牛为主要风险群体。目前对这两类牛的所有个体都进行检测。作为进一步措施，对常规屠宰的奶牛进行随机抽样检测。这有助于独立于临床病例报告系统的不准确性来确定疯牛病状况。这种方法可能有助于可靠地评估发病率较低国家的疯牛病情况，以核实其疯牛病状况，对于那些想要证明自己无疯牛病状态的国家也有帮助。
