Sparkes Jessica, McLeod Steven, Ballard Guy, Fleming Peter J S, Körtner Gerhard, Brown Wendy Y
School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia; Vertebrate Pest Research Unit, Biosecurity NSW, Orange, NSW, 2800, Australia; Invasive Animals Cooperative Research Centre, Armidale, NSW, 2351, Australia.
Vertebrate Pest Research Unit, Biosecurity NSW, Orange, NSW, 2800, Australia.
Prev Vet Med. 2016 Sep 1;131:127-136. doi: 10.1016/j.prevetmed.2016.07.015. Epub 2016 Jul 25.
Currently, Australia is free from terrestrial rabies but an incursion from nearby Indonesia, where the virus is endemic, is a feasible threat. Here, we aimed to determine whether the response to a simulated rabies incursion would vary between three extant Australian dog populations; free-roaming domestic dogs from a remote indigenous community in northern Australia, and free-roaming domestic and wild dogs in peri-urban areas of north-east New South Wales. We further sought to predict how different management strategies impacted disease dynamics in these populations. We used simple stochastic state-transition models and dog demographic and contact rate data from the three dog populations to simulate rabies spread, and used global and local sensitivity analyses to determine effects of model parameters. To identify the most effective control options, dog removal and vaccination strategies were also simulated. Responses to simulated rabies incursions varied between the dog populations. Free-roaming domestic dogs from north-east New South Wales exhibited the lowest risk for rabies maintenance and spread. Due to low containment and high contact rates, rabies progressed rapidly through free-roaming dogs from the remote indigenous community in northern Australia. In contrast, rabies remained at relatively low levels within the north-east New South Wales wild dog population for over a year prior to an epidemic. Across all scenarios, sensitivity analyses revealed that contact rates and the probability of transmission were the most important drivers of the number of infectious individuals within a population. The number of infectious individuals was less sensitive to birth and death rates. Removal of dogs as a control strategy was not effective for any population modelled, while vaccination rates in excess of 70% of the population resulted in significant reductions in disease progression. The variability in response between these distinct dog groups to a rabies incursion, suggests that a blanket approach to management would not be effective or feasible to control rabies in Australia. Control strategies that take into account the different population and behavioural characteristics of these dog groups will maximise the likelihood of effective and efficient rabies control in Australia.
目前，澳大利亚没有陆生狂犬病，但来自附近狂犬病流行的印度尼西亚的病毒传入是一个切实可行的威胁。在此，我们旨在确定对模拟狂犬病传入的反应在澳大利亚现有的三个犬类种群之间是否会有所不同；来自澳大利亚北部偏远原住民社区的自由放养家犬，以及新南威尔士州东北部城郊地区的自由放养家犬和野犬。我们进一步试图预测不同的管理策略如何影响这些种群中的疾病动态。我们使用简单的随机状态转换模型以及来自这三个犬类种群的犬类人口统计学和接触率数据来模拟狂犬病传播，并使用全局和局部敏感性分析来确定模型参数的影响。为了确定最有效的控制选项，还模拟了捕杀犬类和疫苗接种策略。对模拟狂犬病传入的反应在不同犬类种群之间有所不同。新南威尔士州东北部的自由放养家犬维持和传播狂犬病的风险最低。由于控制力度低且接触率高，狂犬病在澳大利亚北部偏远原住民社区的自由放养犬中迅速传播。相比之下，在疫情爆发前的一年多时间里，新南威尔士州东北部的野犬种群中的狂犬病一直处于相对较低的水平。在所有情景中，敏感性分析表明，接触率和传播概率是种群中感染个体数量的最重要驱动因素。感染个体数量对出生率和死亡率不太敏感。作为一种控制策略，捕杀犬类对所模拟的任何种群都无效，而超过种群70%的疫苗接种率会导致疾病传播显著减少。这些不同犬类群体对狂犬病传入的反应差异表明，采用一刀切的管理方法在澳大利亚控制狂犬病既无效也不可行。考虑到这些犬类群体不同的种群和行为特征的控制策略将最大限度地提高澳大利亚有效且高效控制狂犬病的可能性。
