Economic analysis of Mycobacterium avium subspecies paratuberculosis vaccines in dairy herds
Economic analysis of Mycobacterium avium subspecies paratuberculosis vaccines in dairy herds
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DOI：
10.3168/jds.2011-4787
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发表时间：
2012-04-01
影响因子：
3.5
通讯作者：
Grohn, Y. T.
中科院分区：
文献类型：
--
作者：
Cho, J.;Tauer, L. W.;Grohn, Y. T.
约翰氏病（Johne's disease），又称副结核病，是反刍动物的一种慢性肠道传染病，由鸟分枝杆菌（Mycobacterium avium ssp.）副结核病（MAP）。由于缺乏故障安全的预防或治疗方法，约翰氏病可能会对美国乳制品行业造成重大经济损失，估计每年的成本超过2亿美元。目前可用的MAP控制策略包括管理措施，以改善卫生，淘汰MAP血清或粪便阳性的成年奶牛，和疫苗接种。尽管据报道，前两种控制策略可有效降低MAP感染的发生率，但实施这些控制策略所需的牛群管理变化需要乳制品生产商做出重大努力。另一方面，疫苗接种相对简单，只需对畜群管理进行微小的改变。尽管有这些优势，但只有5%的美国乳制品企业使用疫苗接种来控制MAP。这种技术的低水平采用是由于其成本效益和功效的信息有限，以及与当前MAP疫苗相关的一些重要的固有缺点。本研究调查了MAP疫苗在不同开发阶段的流行病学效果和经济价值。我们创建的MAP疫苗的潜在流行病学影响的情况下，然后估计在经济上合理的货币价值，疫苗成为经济上有益的奶制品生产商，使一个农场的净现金流的净现值（NPV）可以高于一个农场的净现值使用无控制或替代nonvaccine控制。本研究中考虑的任何低或高效力的疫苗接种与无MAP对照相比产生更高的NPV。此外，与替代对照相比，高效疫苗产生更高的NPV，使疫苗接种在经济上具有吸引力。两种高效疫苗在MAP控制和NPV最大化方面特别有效。一种是降低MAP感染易感性的高效疫苗。另一种是高效疫苗，对MAP感染和疾病进展的动力学具有多重功效。只有一种高效疫苗，其中疫苗的目标是减少MAP脱落和临床病例的数量，与替代的非疫苗对照相比，当牛群高度感染MAP时，对乳制品生产商没有经济效益。
Johne's disease, or paratuberculosis, is a chronic infectious enteric disease of ruminants, caused by infection with Mycobacterium avium ssp. paratuberculosis (MAP). Given the absence of a fail-safe method of prevention or a cure, Johne's disease can inflict significant economic loss on the US dairy industry, with an estimated annual cost of over $200 million. Currently available MAP control strategies include management measures to improve hygiene, culling MAP serologic- or fecal-positive adult cows, and vaccination. Although the 2 first control strategies have been reported to be effective in reducing the incidence of MAP infection, the changes in herd management needed to conduct these control strategies require significant effort on the part of the dairy producer. On the other hand, vaccination is relatively simple to apply and requires minor changes in herd management. Despite these advantages, only 5% of US dairy operations use vaccination to control MAP. This low level of adoption of this technology is due to limited information on its cost-effectiveness and efficacy and some important inherent drawbacks associated with current MAP vaccines. This study investigates the epidemiological effect and economic values of MAP vaccines in various stages of development. We create scenarios for the potential epidemiological effects of MAP vaccines, and then estimate economically justifiable monetary values at which vaccines become economically beneficial to dairy producers such that a net present value (NPV) of a farm's net cash flow can be higher than the NPV of a farm using no control or alternative nonvaccine controls. Any vaccination with either low or high efficacy considered in this study yielded a higher NPV compared with a no MAP control. Moreover, high-efficacy vaccines generated an even higher NPV compared with alternative controls, making vaccination economically attractive. Two high-efficacy vaccines were particularly effective in MAP control and NPV maximization. One was a high-efficacy vaccine that reduced susceptibility to MAP infection. The other was a high-efficacy vaccine that had multiple efficacies on the dynamics of MAP infection and disease progress. Only one high-efficacy vaccine, in which the vaccine is targeted at reducing MAP shedding and the number of clinical cases, was not economically beneficial to dairy producers compared with an alternative nonvaccine control, when herds were highly infected with MAP.