Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, CO, USA.
National Wildlife Research Center, United States Department of Agriculture, Animal and Plant Health Inspection Service, Fort Collins, CO, USA.
J Anim Ecol. 2021 Apr;90(4):820-833. doi: 10.1111/1365-2656.13412. Epub 2021 Jan 9.
Contact heterogeneity among hosts determines invasion and spreading dynamics of infectious disease, thus its characterization is essential for identifying effective disease control strategies. Yet, little is known about the factors shaping contact networks in many wildlife species and how wildlife management actions might affect contact networks. Wild pigs in North America are an invasive, socially structured species that pose a health concern for domestic swine given their ability to transmit numerous devastating diseases such as African swine fever (ASF). Using proximity loggers and GPS data from 48 wild pigs in Florida and South Carolina, USA, we employed a probabilistic framework to estimate weighted contact networks. We determined the effects of sex, social group and spatial distribution (monthly home-range overlap and distance) on wild pig contact. We also estimated the impacts of management-induced perturbations on contact and inferred their effects on ASF establishment in wild pigs with simulation. Social group membership was the primary factor influencing contacts. Between-group contacts depended primarily on space use characteristics, with fewer contacts among groups separated by >2 km and no contacts among groups >4 km apart within a month. Modelling ASF dynamics on the contact network demonstrated that indirect contacts resulting from baiting (a typical method of attracting wild pigs or game species to a site to enhance recreational hunting) increased the risk of disease establishment by ~33% relative to direct contact. Low-intensity population reduction (<5.9% of the population) had no detectable impact on contact structure but reduced predicted ASF establishment risk relative to no population reduction. We demonstrate an approach for understanding the relative role of spatial, social and individual-level characteristics in shaping contact networks and predicting their effects on disease establishment risk, thus providing insight for optimizing disease control in spatially and socially structured wildlife species.
宿主间的接触异质性决定了传染病的入侵和传播动态，因此其特征描述对于确定有效的疾病控制策略至关重要。然而，对于许多野生动物物种中形成接触网络的因素以及野生动物管理措施如何影响接触网络，人们知之甚少。北美的野猪是一种入侵性的、具有社会结构的物种，由于它们能够传播许多毁灭性的疾病，如非洲猪瘟（ASF），因此对家猪构成了健康威胁。本研究在美国佛罗里达州和南卡罗来纳州的 48 头野猪中使用接近记录仪和 GPS 数据，采用概率框架来估计加权接触网络。我们确定了性别的影响、社会群体以及空间分布（每月的家域重叠和距离）对野猪接触的影响。我们还估计了管理诱导的干扰对接触的影响，并通过模拟推断了它们对 ASF 在野猪中建立的影响。社会群体成员资格是影响接触的主要因素。群体间的接触主要取决于空间利用特征，相隔 >2km 的组之间的接触较少，一个月内相隔 >4km 的组之间没有接触。在接触网络上模拟 ASF 动态表明，诱捕（一种吸引野猪或猎物到一个地点以增强娱乐性狩猎的典型方法）导致的间接接触使疾病建立的风险增加了约 33%，与直接接触相比。低强度的种群减少（<5.9%的种群）对接触结构没有明显影响，但与不减少种群相比，降低了预测的 ASF 建立风险。我们展示了一种理解空间、社会和个体水平特征在塑造接触网络和预测其对疾病建立风险的影响方面的相对作用的方法，从而为优化空间和社会结构野生动物物种的疾病控制提供了见解。
