Intelligence Community Postdoctoral Research Fellowship Program, Oak Ridge, TN, USA.
Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA, USA.
J R Soc Interface. 2021 Mar;18(176):20200933. doi: 10.1098/rsif.2020.0933. Epub 2021 Mar 3.
Livestock diseases have devastating consequences economically, socially and politically across the globe. In certain systems, pathogens remain viable after host death, which enables residual transmissions from infected carcasses. Rapid culling and carcass disposal are well-established strategies for stamping out an outbreak and limiting its impact; however, wait-times for these procedures, i.e. response delays, are typically farm-specific and time-varying due to logistical constraints. Failing to incorporate variable response delays in epidemiological models may understate outbreak projections and mislead management decisions. We revisited the 2001 foot-and-mouth epidemic in the United Kingdom and sought to understand how misrepresented response delays can influence model predictions. Survival analysis identified farm size and control demand as key factors that impeded timely culling and disposal activities on individual farms. Using these factors in the context of an existing policy to predict local variation in response times significantly affected predictions at the national scale. Models that assumed fixed, timely responses grossly underestimated epidemic severity and its long-term consequences. As a result, this study demonstrates how general inclusion of response dynamics and recognition of partial controllability of interventions can help inform management priorities during epidemics of livestock diseases.
家畜疾病在全球范围内给经济、社会和政治带来了毁灭性的后果。在某些系统中，病原体在宿主死亡后仍然具有活力，这使得受感染的尸体能够继续传播病原体。快速扑杀和处理尸体是扑灭疫情和限制其影响的既定策略；然而，这些程序的等待时间，即响应延迟，通常因后勤限制而因农场而异且随时间变化。如果在流行病学模型中不考虑可变的响应延迟，则可能会低估疫情预测并误导管理决策。我们重新研究了 2001 年在英国发生的口蹄疫疫情，并试图了解响应延迟的代表性不足如何影响模型预测。生存分析确定了农场规模和控制需求是阻碍个别农场及时扑杀和处理活动的关键因素。在现有的政策背景下，使用这些因素来预测响应时间的局部变化，会显著影响国家范围内的预测。假设固定、及时响应的模型严重低估了疫情的严重程度及其长期后果。因此，这项研究表明，如何普遍纳入响应动态并认识到干预措施的部分可控性，可以帮助在家畜疾病疫情期间为管理重点提供信息。
