Application of an individual based model with real data of transportation mode and location to pandemic influenza

尽管区域隔离被认为是最好的快速控制流感大流行的策略之一，但在不同的环境中检查各种干预措施的潜在有效性至关重要。这项研究旨在评估关闭运输系统的潜在效果，并将其与其他措施的效果进行比较，如设施关闭和地区隔离。一个基于代理人的模型，它明确地描绘了一个社区的家庭分布和家庭结构的人口与90万人，是用于此分析。比较了每种措施的有效性和灭绝概率。在指定的累积病例数开始关闭列车系统的有效性似乎为2.16%（95%置信区间（CI）：[1.81，2.84]），但在相同阈值关闭所有设施可更有效地减少临床明显感染的数量（25.6%有效性，95% CI：[25.1，26.5]）。此外，如果在流行病的早期阶段（即，如果我们在临床报告的累积比例超过人口的1%时立即开始这两项措施），结果表明，交通系统的关闭对病例数没有特别的影响。然而，还证明了如果列车内的传输概率高于列车内无传输，则停机可以将成功遏制的概率增加20%。我们的研究表明，区域隔离对于有效减少大流行的传播比关闭火车更重要，但如果交通系统内的传播概率极高，并且如果措施具有足够的成本效益，关闭火车可能是有价值的。

Though area quarantine has been proposed as one of the best rapid control strategies against pandemic influenza, it is of critical importance to examine the potential effectiveness of various interventions in different settings. This study was aimed at assessing the potential effectiveness of shutting down transportation systems and comparing this with the effectiveness of other measures, such as facility closure and area quarantine. An agent-based model, which explicitly depicts household distributions and family structures of a community populated with 900,000 individuals, was employed for this analysis. The effectiveness of each measure and probabilities of extinction were compared. Shutting down the train system starting at a specified cumulative number of cases appeared to be 2.16% (95% confidence interval (CI) : [1.81, 2.84]) effective, but closing all facilities at the same threshold reduced the number of clinically apparent infections more efficiently (25.6% effective, 95% CI : [25.1, 26.5]). Moreover, if these measures are combined at an early stage of the epidemic (i.e., if we start both measures immediately at the time a cumulative proportion of clinical reports exceeds 1% of the population), it was shown that the shutdown of transportation systems did not have particular influence on the number of cases. However, it was also demonstrated that the shutdown can increase the probability of successful containment by 20% if the transmission probability within trains is high compared to no transmission within trains. Our study implies that area quarantine is more important to effectively reduce the spread of a pandemic, rather than shutting down trains, but that it might be valuable to shut down trains if the transmission probability within the transportation system is extremely high and if the measure is sufficiently cost effective.