Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK.
J R Soc Interface. 2022 Jan;19(186):20210718. doi: 10.1098/rsif.2021.0718. Epub 2022 Jan 12.
Epidemics can particularly threaten certain sub-populations. For example, for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the elderly are often preferentially protected. For diseases of plants and animals, certain sub-populations can drive mitigation because they are intrinsically more valuable for ecological, economic, socio-cultural or political reasons. Here, we use optimal control theory to identify strategies to optimally protect a 'high-value' sub-population when there is a limited budget and epidemiological uncertainty. We use protection of the Redwood National Park in California in the face of the large ongoing state-wide epidemic of sudden oak death (caused by ) as a case study. We concentrate on whether control should be focused entirely within the National Park itself, or whether treatment of the growing epidemic in the surrounding 'buffer region' can instead be more profitable. We find that, depending on rates of infection and the size of the ongoing epidemic, focusing control on the high-value region is often optimal. However, priority should sometimes switch from the buffer region to the high-value region only as the local outbreak grows. We characterize how the timing of any switch depends on epidemiological and logistic parameters, and test robustness to systematic misspecification of these factors due to imperfect prior knowledge.
传染病特别会威胁到某些特定人群。例如，对于严重急性呼吸系统综合症冠状病毒 2（SARS-CoV-2），老年人通常是优先受到保护的对象。对于动植物的疾病来说，某些特定人群可能会成为缓解疾病的驱动因素，因为出于生态、经济、社会文化或政治等原因，他们具有内在的更高价值。在这里，我们使用最优控制理论来确定在预算有限且存在流行病学不确定性的情况下，如何最优地保护“高价值”人群。我们以加利福尼亚州红杉国家公园在面对大型正在进行的橡树突然死亡的全州性流行（由 ）时的保护情况为例。我们专注于控制措施是应该完全集中在国家公园本身，还是对周围“缓冲区”中不断发展的流行情况进行处理会更有利可图。我们发现，取决于感染率和正在进行的流行规模，将控制措施集中在高价值地区通常是最优的。然而，只有当局部疫情发展时，才应优先考虑将重点从缓冲区转移到高价值区域。我们描述了任何切换的时机如何取决于流行病学和物流参数，并针对由于不完善的先验知识而导致对这些因素的系统误报进行了稳健性测试。
