Severns Paul M, Mundt Christopher C
Department of Plant Pathology, University of Georgia, Athens, GA 30602, USA.
Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA.
Pathogens. 2022 Mar 24;11(4):393. doi: 10.3390/pathogens11040393.
Epidemic outbreak control often involves a spatially explicit treatment area (quarantine, inoculation, ring cull) that covers the outbreak area and adjacent regions where hosts are thought to be latently infected. Emphasis on space however neglects the influence of treatment timing on outbreak control. We conducted field and in silico experiments with wheat stripe rust (WSR), a long-distance dispersed plant disease, to understand interactions between treatment timing and area interact to suppress an outbreak. Full-factorial field experiments with three different ring culls (outbreak area only to a 25-fold increase in treatment area) at three different disease control timings (1.125, 1.25, and 1.5 latent periods after initial disease expression) indicated that earlier treatment timing had a conspicuously greater suppressive effect than the area treated. Disease spread computer simulations over a broad range of influential epidemic parameter values (R, outbreak disease prevalence, epidemic duration) suggested that potentially unrealistically large increases in treatment area would be required to compensate for even small delays in treatment timing. Although disease surveillance programs are costly, our results suggest that treatments early in an epidemic disease outbreak require smaller areas to be effective, which may ultimately compensate for the upfront costs of proactive disease surveillance programs.
疫情爆发控制通常涉及一个空间明确的处理区域（检疫、接种、环状扑杀），该区域覆盖爆发区域以及据认为宿主存在潜伏感染的相邻区域。然而，对空间的强调忽略了处理时机对疫情控制的影响。我们对小麦条锈病（一种远距离传播的植物病害）进行了田间和计算机模拟实验，以了解处理时机和处理区域之间的相互作用如何抑制疫情爆发。在三个不同的疾病控制时机（初始病害表现后的1.125、1.25和1.5个潜伏期）进行了三种不同环状扑杀（仅爆发区域到处理区域增加25倍）的全因子田间实验，结果表明，更早的处理时机比处理区域具有明显更大的抑制效果。在广泛的有影响力的疫情参数值（R、爆发疾病患病率、疫情持续时间）范围内进行的疾病传播计算机模拟表明，即使是处理时机上的小延迟，也可能需要大幅增加处理区域，而这可能不切实际。尽管疾病监测计划成本高昂，但我们的结果表明，在疫情爆发初期进行处理所需的有效区域较小，这最终可能弥补主动疾病监测计划的前期成本。
