When a region tries to prevent an outbreak of an epidemic, two broad strategies are available: limiting the inflow of infected cases by using travel restrictions and quarantines or limiting the risk of local transmission from imported cases by using contact tracing and other community interventions. A number of papers have used epidemiological models to argue that inflow restrictions are unlikely to be effective. We simulate a simple epidemiological model to show that this conclusion changes if containment efforts such as contact tracing have limited capacity. In particular, our results show that moderate travel restrictions can lead to large reductions in the probability of an epidemic when contact tracing is effective but the contact tracing system is close to being overwhelmed.

中文翻译：

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当接触者追踪工作有效但能力有限时，流入限制可以预防流行病

当一个地区试图防止流行病爆发时，可以使用两种广泛的策略：通过使用旅行限制和隔离来限制感染病例的流入，或通过使用接触者追踪和其他社区干预措施来限制输入病例在本地传播的风险。许多论文使用流行病学模型来论证流入限制不太可能有效。我们模拟了一个简单的流行病学模型，以表明如果接触者追踪等遏制措施的能力有限，则该结论会发生变化。特别是，我们的研究结果表明，当接触者追踪有效但接触者追踪系统接近不堪重负时，适度的旅行限制可以大大降低流行病的可能性。