Thrusfield M, Mansley L, Dunlop P, Pawson A, Taylor J
Veterinary Clinical Studies, University of Edinburgh, Easter Bush Veterinary Centre, Roslin EH25 9RG.
Vet Rec. 2005 Feb 26;156(9):269-78. doi: 10.1136/vr.156.9.269.
After the foot-and-mouth disease (FMD) epidemic in Dumfries and Galloway in south-west Scotland in 2001, serosurveillance of sheep remaining in the 3 km radius Protection Zones around Infected Premises (IPS), and within a 10 km radius of IPS, revealed no evidence of infection. The epidemic was brought under control by a range of traditional techniques: slaughter of all animals on IPS and of veterinary-assessed Dangerous Contacts (DCS), movement restrictions, biosecurity, tracing of potential sources and spread of virus, and surveillance of At-Risk premises. Novel pre-emptive slaughter of FMD-susceptible animals on premises contiguous to IPS, and small ruminants and pigs on premises within 3 km of IPSs, commenced after the epidemic had peaked. Most of the traditional control procedures were undertaken quickly and with appropriate priority. Animals on IPS were usually slaughtered within one day of confirmation, and veterinary-assessed DCS within two days of confirmation of relevant IPS (a median of two days). The pre-emptive contiguous and 3 km culls took somewhat longer (medians of five and 17 days, respectively). IPS were most commonly identified as a result of reporting by farmers or their veterinarians (72 per cent of IPS); veterinary clinical patrols identified 16 per cent, while veterinary assessment of DCS and tracing each identified 5 per cent. No evidence of infection was found on any pre-emptively contiguously culled premises, and IPS were declared only on three 3 km cull premises. The time from estimated first lesion to end of slaughter on an IP was found, by regression analysis, to be a key component in effective control, manifested by a reduction in the estimated dissemination rate (EDR); there was little evidence that the intensity of contiguous culling affected the EDR. Patrols and serological surveillance of residual animals within 10 km of IPS, supported by more extensive evidence from elsewhere in the UK, suggested that cryptic infection in sheep was not widespread. Ultimately, there was insufficient evidence to support the effectiveness of 3 km pre-emptive culling as a control procedure.
2001年苏格兰西南部邓弗里斯和加洛韦地区发生口蹄疫疫情后，对感染场所（IPS）周围半径3公里保护区内以及IPS半径10公里范围内留存的绵羊进行血清学监测，未发现感染迹象。通过一系列传统技术控制了疫情：宰杀IPS上的所有动物以及经兽医评估的危险接触动物（DCS）、实施移动限制、加强生物安全措施、追踪病毒的潜在来源和传播途径以及对风险场所进行监测。在疫情达到高峰后，开始对IPS相邻场所的口蹄疫易感动物以及距离IPS 3公里范围内场所的小型反刍动物和猪进行新型预防性宰杀。大多数传统控制程序迅速且按适当的优先顺序进行。IPS上的动物通常在确诊后一天内宰杀，经兽医评估的DCS在相关IPS确诊后两天内宰杀（中位数为两天）。预防性相邻宰杀和3公里范围内宰杀耗时稍长（中位数分别为五天和十七天）。IPS最常见的是由农民或其兽医报告而确定（占IPS的72%）；兽医临床巡逻发现16%，而对DCS的兽医评估和追踪各发现5%。在任何预防性相邻宰杀的场所均未发现感染迹象，仅在三个3公里范围内宰杀的场所宣布发现了IPS。通过回归分析发现，从估计的首次发病到IPS宰杀结束的时间是有效控制的关键因素，表现为估计传播率（EDR）降低；几乎没有证据表明相邻宰杀的强度会影响EDR。对IPS 10公里范围内剩余动物的巡逻和血清学监测，以及来自英国其他地区更广泛的证据表明，绵羊的隐性感染并不普遍。最终，没有足够的证据支持3公里范围内预防性宰杀作为一种控制程序的有效性。
