Potential benefits of cattle vaccination as a supplementary control for bovine tuberculosis.
Potential benefits of cattle vaccination as a supplementary control for bovine tuberculosis.
复制标题
DOI：
10.1371/journal.pcbi.1004038
复制
发表时间：
2015-02
影响因子：
4.3
通讯作者：
Wood JL
中科院分区：
文献类型：
--
作者：
Conlan AJ;Brooks Pollock E;McKinley TJ;Mitchell AP;Jones GJ;Vordermeier M;Wood JL
为控制牛结核病（bTB）接种疫苗目前没有在任何国际控制计划中使用，并且在欧盟是非法的。基于牛分枝杆菌卡介苗（BCG）的候选疫苗都会干扰结核菌素皮肤试验的作用，结核菌素皮肤试验用于确定动物、牛群和国家是否正式无结核。区分感染动物和接种动物的新诊断测试（DIVA）提供了在现有根除计划中引入疫苗接种的潜力。我们使用从英国（GB）的历史数据估计的猪群内传播模型来探索这种补充使用疫苗的可行性。牛结核病对农民的经济影响主要是与检测相关的费用以及对动物活动的相关限制。农民采用疫苗接种的意愿将要求疫苗接种不仅可以减轻感染负担，还可以降低被施加限制的风险。我们发现，在GB密集的检测序列下，DIVA检测的特异性，而不是敏感性，是看到接种疫苗的群体水平效益的最大障碍。疫苗接种的潜在负面影响可以通过放松检测来减轻。然而，这可能会潜在地增加官方无结核病畜群中的隐性感染负担。使用我们的模型，我们探索了DIVA测试特征的范围，这是看到接种疫苗的保护性群体水平效益所必需的。我们估计，DIVA特异性至少为99.85%，敏感性至少为bbb40 %，才能看到疫苗接种的保护效益，而不会增加遗漏感染的风险。来自实验感染动物的数据表明，使用三种DIVA抗原的鸡尾酒疫苗可以实现这种目标特异性，同时相对于死后检测保持73.3% （95%CI: 61.9, 82.9%）的敏感性。牛结核病（bTB）是世界范围内主要的家畜经济疾病。尽管英国实施了密集和昂贵的控制规划，但结核仍然持续存在。接种疫苗可以为牛提供一些保护，但由于卡介苗与结核菌素皮肤试验的作用相互作用，目前在欧盟是非法的。欧盟已发出信号，立法的变化将要求对BCG进行实地验证，作为现有控制措施的补充。一个特别值得关注的问题是，对疫苗的前瞻性DIVA测试的灵敏度不完善，可能会增加在畜群中错过感染的机会。然而，我们证明了DIVA的高特异性也将是必不可少的，以便农民看到疫苗接种的保护畜群水平的好处，就他们受到测试的频率和被拒绝的动物数量而言。DIVA测试的现场验证将是在现场使用BCG的必要先决条件。我们估计的靶特异性为在现场部署前验证前瞻性DIVA测试提供了一个重要标准。
Vaccination for the control of bovine tuberculosis (bTB) in cattle is not currently used within any international control program, and is illegal within the EU. Candidate vaccines, based upon Mycobacterium bovis bacillus Calmette-Guérin (BCG) all interfere with the action of the tuberculin skin test, which is used to determine if animals, herds and countries are officially bTB-free. New diagnostic tests that Differentiate Infected from Vaccinated Animals (DIVA) offer the potential to introduce vaccination within existing eradication programs. We use within-herd transmission models estimated from historical data from Great Britain (GB) to explore the feasibility of such supplemental use of vaccination. The economic impact of bovine Tuberculosis for farmers is dominated by the costs associated with testing, and associated restrictions on animal movements. Farmers’ willingness to adopt vaccination will require vaccination to not only reduce the burden of infection, but also the risk of restrictions being imposed. We find that, under the intensive sequence of testing in GB, it is the specificity of the DIVA test, rather than the sensitivity, that is the greatest barrier to see a herd level benefit of vaccination. The potential negative effects of vaccination could be mitigated through relaxation of testing. However, this could potentially increase the hidden burden of infection within Officially TB Free herds. Using our models, we explore the range of the DIVA test characteristics necessary to see a protective herd level benefit of vaccination. We estimate that a DIVA specificity of at least 99.85% and sensitivity of >40% is required to see a protective benefit of vaccination with no increase in the risk of missed infection. Data from experimentally infected animals suggest that this target specificity could be achieved in vaccinates using a cocktail of three DIVA antigens while maintaining a sensitivity of 73.3% (95%CI: 61.9, 82.9%) relative to post-mortem detection. Bovine tuberculosis (bTB) is a major economic disease of livestock worldwide. Despite an intensive, and costly, control program in the United Kingdom, bTB continues to persist. Vaccination can provide some protection to cattle, but is currently illegal within the European Union due to the interaction of BCG with the action of the tuberculin skin test. The EU has signaled that changes in legislation will require field validation of BCG as a supplement to existing controls. A particular concern is that the imperfect sensitivity of prospective DIVA tests for vaccinates may increase the chances of infection being missed within herds. However, we demonstrate that high DIVA specificity will also be essential in order for farmers to see a protective herd level benefit of vaccination in terms of the frequency of tests they are subjected to and number of animals condemned. Field validation of the DIVA test will be an essential prerequisite to use of BCG in the field. Our estimated target specificity provides an important criterion for validation of prospective DIVA tests before deployment in the field.
登录
查看更多内容
DOI：
10.1111/j.1475-5661.2011.00452.x
发表时间：
2012-01-01
影响因子：
3.3
作者：
Enticott, Gareth
通讯作者：
Enticott, Gareth
影响因子：
3.3
作者：
Authie, Edith;Berg, Charlotte;Zientara, Stephan
通讯作者：
Zientara, Stephan
DOI：
10.1098/rspb.2013.1634
发表时间：
2013-10-07
期刊：
Proceedings. Biological sciences
影响因子：
--
作者：
Godfray HC;Donnelly CA;Kao RR;Macdonald DW;McDonald RA;Petrokofsky G;Wood JL;Woodroffe R;Young DB;McLean AR
通讯作者：
McLean AR
影响因子：
3.2
作者：
Goodchild, AV;Clifton-Hadley, RS
通讯作者：
Clifton-Hadley, RS
影响因子：
3.3
作者：
Authie, Edit;Berg, Charlotte;Zientara, Stephan
通讯作者：
Zientara, Stephan