Hayes Brandon H, Andraud Mathieu, Salazar Luis G, Rose Nicolas, Vergne Timothée
UMR ENVT-INRAE IHAP, National Veterinary School of Toulouse, 31000, Toulouse, France; Epidemiology Health and Welfare Department, Ploufragan-Plouzané-Niort Laboratory, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 22440, Ploufragan, France.
Epidemiology Health and Welfare Department, Ploufragan-Plouzané-Niort Laboratory, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 22440, Ploufragan, France.
Prev Vet Med. 2021 Apr 18;191:105358. doi: 10.1016/j.prevetmed.2021.105358.
The spread of African swine fever (ASF) poses a grave threat to the global swine industry. Without an available vaccine, understanding transmission dynamics is essential for designing effective prevention, surveillance, and intervention strategies. These dynamics can often be unraveled through mechanistic modelling. To examine the assumptions on transmission and objectives of the mechanistic models of ASF, a systematic review of the scientific literature was conducted. Articles were examined across multiple epidemiological and model characteristics, with filiation between models determined through the creation of a neighbor-joined tree using phylogenetic software. Thirty-four articles qualified for inclusion, with four main modelling objectives identified: estimating transmission parameters (11 studies), assessing determinants of transmission (7), examining consequences of hypothetical outbreaks (5), assessing alternative control strategies (11). Population-based (17), metapopulation (5), and individual-based (12) model frameworks were represented, with population-based and metapopulation models predominantly used among domestic pigs, and individual-based models predominantly represented among wild boar. The majority of models (25) were parameterized to the genotype II isolates currently circulating in Europe and Asia. Estimated transmission parameters varied widely among ASFV strains, locations, and transmission scale. Similarly, parameter assumptions between models varied extensively. Uncertainties on epidemiological and ecological parameters were usually accounted for to assess the impact of parameter values on the modelled infection trajectory. To date, almost all models are host specific, being developed for either domestic pigs or wild boar despite the fact that spillover events between domestic pigs and wild boar are evidenced to play an important role in ASF outbreaks. Consequently, the development of more models incorporating such transmission routes is crucial. A variety of codified and hypothetical control strategies were compared however they were all a priori defined interventions. Future models, built to identify the optimal contributions across many control methods for achieving specific outcomes should provide more useful information for policy-makers. Further, control strategies were examined in competition with each other, which is opposed to how they would actually be synergistically implemented. While comparing strategies is beneficial for identifying a rank-order efficacy of control methods, this structure does not necessarily determine the most effective combination of all available strategies. In order for ASFV models to effectively support decision-making in controlling ASFV globally, these modelling limitations need to be addressed.
非洲猪瘟（ASF）的传播对全球养猪业构成了严重威胁。由于尚无可用疫苗，了解传播动态对于设计有效的预防、监测和干预策略至关重要。这些动态通常可以通过机理建模来揭示。为了检验ASF机理模型的传播假设和目标，我们对科学文献进行了系统综述。我们考察了多篇文章的多种流行病学和模型特征，并使用系统发育软件创建邻接树来确定模型之间的亲缘关系。34篇文章符合纳入标准，确定了四个主要建模目标：估计传播参数（11项研究）、评估传播的决定因素（7项）、研究假设疫情的后果（5项）、评估替代控制策略（11项）。研究涵盖了基于种群的模型（17个）、集合种群模型（5个）和基于个体的模型（12个），基于种群的模型和集合种群模型主要用于家猪研究，基于个体的模型主要用于野猪研究。大多数模型（25个）针对目前在欧洲和亚洲传播的II型基因型毒株进行了参数化。估计的传播参数在非洲猪瘟病毒株、地点和传播规模之间差异很大。同样，模型之间的参数假设也有很大差异。通常会考虑流行病学和生态参数的不确定性，以评估参数值对模拟感染轨迹的影响。迄今为止，几乎所有模型都是针对特定宿主的，要么是为家猪开发的，要么是为野猪开发的，尽管有证据表明家猪和野猪之间的溢出事件在非洲猪瘟疫情中起着重要作用。因此，开发更多纳入此类传播途径的模型至关重要。我们比较了各种编纂和假设的控制策略，但它们都是先验定义的干预措施。未来构建用于确定多种控制方法对实现特定结果的最佳贡献的模型，应为政策制定者提供更有用的信息。此外，我们考察的控制策略是相互竞争的，这与它们实际协同实施的方式相反。虽然比较策略有助于确定控制方法的排序疗效，但这种结构不一定能确定所有可用策略的最有效组合。为了使非洲猪瘟病毒模型有效地支持全球控制非洲猪瘟的决策，需要解决这些建模局限性。
