National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, United States Department of Agriculture, Fort Collins, Colorado, USA.
United States Department of Agriculture, Animal and Plant Health Inspection Services, Wildlife Services, National Feral Swine Damage Management Program, Fort Collins, Colorado, USA.
Transbound Emerg Dis. 2022 Sep;69(5):e3111-e3127. doi: 10.1111/tbed.14668. Epub 2022 Aug 9.
African swine fever virus (ASFv) is a virulent pathogen that threatens domestic swine industries globally and persists in wild boar populations in some countries. Persistence in wild boar can challenge elimination and prevent disease-free status, making it necessary to address wild swine in proactive response plans. In the United States, invasive wild pigs are abundant and found across a wide range of ecological conditions that could drive different epidemiological dynamics among populations. Information on the size of the control areas required to rapidly eliminate the ASFv in wild pigs and how this area should change with management constraints and local ecology is needed to optimize response planning. We developed a spatially explicit disease transmission model contrasting wild pig movement and contact ecology in two ecosystems in Southeastern United States. We simulated ASFv spread and determined the optimal response area (reported as the radius of a circle) for eliminating ASFv rapidly over a range of detection times (when ASFv was detected relative to the true date of introduction), culling capacities (proportion of wild pigs in the culling zone removed weekly) and wild pig densities. Large radii for response areas (14 km) were needed under most conditions but could be shortened with early detection (≤ 8 weeks) and high culling capacities (≥ 15% weekly). Under most conditions, the ASFv was eliminated in less than 22 weeks using optimal control radii, although ecological conditions with high rates of wild pig movement required higher culling capacities (≥ 10% weekly) for elimination within 1 year. The results highlight the importance of adjusting response plans based on local ecology and show that wild pig movement is a better predictor of the optimal response area than the number of ASFv cases early in the outbreak trajectory. Our framework provides a tool for determining optimal control plans in different areas, guiding expectations of response impacts, and planning resources needed for rapid elimination.
非洲猪瘟病毒（ASFv）是一种烈性病原体，它对全球的家猪产业构成威胁，并在一些国家的野猪种群中持续存在。野猪中的持续存在可能会对消灭工作造成挑战，并阻碍无病状态的实现，因此必须积极应对野猪问题，将其纳入到预防性应对计划中。在美国，入侵的野猪数量众多，分布范围广泛，存在于各种生态条件下，这可能导致不同种群之间存在不同的流行病学动态。为了优化应对计划，我们需要了解在野猪中迅速消灭 ASFv 所需的控制区域的大小，以及如何根据管理限制和当地生态条件改变该区域。我们开发了一种空间明确的疾病传播模型，对比了美国东南部两个生态系统中野猪的移动和接触生态学。我们模拟了 ASFv 的传播，并确定了在不同检测时间（即相对于 ASFv 实际引入时间的检测时间）、扑杀能力（扑杀区域内每周被扑杀的野猪比例）和野猪密度下，快速消灭 ASFv 的最佳响应区域（以圆形的半径报告）。在大多数情况下，需要较大的响应区域半径（14 公里），但通过早期检测（≤8 周）和高扑杀能力（每周≥15%）可以缩短该半径。在大多数情况下，使用最佳控制半径可以在不到 22 周的时间内消灭 ASFv，尽管在野猪移动速度较高的生态条件下，需要更高的扑杀能力（每周≥10%）才能在 1 年内消灭 ASFv。结果强调了根据当地生态条件调整应对计划的重要性，并表明野猪的移动比疫情早期的 ASFv 病例数量更能预测最佳响应区域。我们的框架提供了一种在不同地区确定最佳控制计划的工具，有助于了解应对措施的影响，并规划快速消灭所需的资源。
