Office of the Chief Veterinary Officer, Department of Agriculture, Fisheries and Forestry, GPO Box 858, 18 Marcus Clarke St, Canberra, ACT 2601, Australia.
Prev Vet Med. 2011 Apr 1;99(1):15-27. doi: 10.1016/j.prevetmed.2010.02.007. Epub 2010 Mar 16.
In August 2007, Australia which had previously been free of equine influenza, experienced a large outbreak that lasted approximately 4 months before it was eradicated. The outbreak required a significant national response by government and the horse industries. The main components of the response were movement controls, biosecurity measures, risk-based zoning and, subsequently, vaccination to contain the outbreak. Although not initially used, vaccination became a key element in the eradication program, with approximately 140000 horses vaccinated. Vaccination is recognised as a valuable tool for managing EI in endemically infected countries but there is little experience using it in situations where the objective is disease eradication. Vaccination was undoubtedly an important factor in 2007 as it enabled movements of some horses and associated industry activities to recommence. However, its contribution to containment and eradication is less clear. A premises-level equine influenza model, based on an epidemiological analysis of the 2007 outbreak, was developed to evaluate effectiveness of the mitigation strategies used and to investigate whether vaccination, if applied earlier, would have had an effect on the course of the outbreak. The results indicate that early use of strategic vaccination could have significantly reduced the size of the outbreak. The four vaccination strategies evaluated had, by 1 month into the control program, reduced the number of new infections on average by 60% and the size of the infected area by 8-9%. If resources are limited, a 1 km suppressive ring vaccination around infected premises gave the best results, but with greater vaccination capacity, a 3 km ring vaccination was the most effective strategy. The findings suggest that as well as reducing clinical and economic impacts, vaccination when used with biosecurity measures and movement controls could play an important role in the containment and eradication of equine influenza.
2007 年 8 月,澳大利亚曾一度没有发生过马流感,但随后经历了一场持续约 4 个月的大爆发才得以根除。此次爆发需要政府和马业作出重大的全国性响应。应对措施的主要内容包括移动控制、生物安全措施、基于风险的分区,以及随后为控制疫情而进行的疫苗接种。虽然最初并未使用,但疫苗接种成为根除计划的一个关键要素,约有 14 万匹马接种了疫苗。疫苗接种被认为是管理在地方性流行国家的 EI 的一种有价值的工具,但在以根除疾病为目标的情况下,使用这种方法的经验却很少。在 2007 年,疫苗接种无疑是一个重要因素,因为它使一些马匹的移动和相关的行业活动得以重新开始。然而,其对控制和根除的贡献却不太明确。根据 2007 年疫情的流行病学分析,建立了一个基于场所的马流感模型,以评估所使用的缓解策略的有效性,并研究如果更早地应用疫苗接种,是否会对疫情的进程产生影响。结果表明,早期使用策略性疫苗接种可以显著减少疫情的规模。所评估的四种疫苗接种策略,在控制计划实施一个月后,平均将新感染的数量减少了 60%,受感染地区的面积减少了 8-9%。如果资源有限,在受感染场所周围进行 1 公里的抑制性环形疫苗接种效果最好,但如果疫苗接种能力更大,3 公里的环形疫苗接种则是最有效的策略。研究结果表明,疫苗接种除了可以减少临床和经济影响外,在与生物安全措施和移动控制相结合使用时,还可以在马流感的控制和根除中发挥重要作用。