Biosecurity Program, Kirby Institute, Faculty of Medicine, The University of New South Wales, Sydney, New South Wales, Australia.
College of Public Service and Community Solutions, Arizona State University, Tempe, Arizona, United States of America.
PLoS One. 2019 Jun 14;14(6):e0217704. doi: 10.1371/journal.pone.0217704. eCollection 2019.
Planning for a re-emergent epidemic of smallpox requires surge capacity of space, resources and personnel within health systems. There are many uncertainties in such a scenario, including likelihood and size of an attack, speed of response and health system capacity. We used a model for smallpox transmission to determine requirements for hospital beds, contact tracing and health workers (HCWs) in Sydney, Australia, during a modelled epidemic of smallpox. Sensitivity analysis was done on attack size, speed of response and proportion of case isolation and contact tracing. We estimated 100638 clinical HCWs and 14595 public hospital beds in Sydney. Rapid response, case isolation and contact tracing are influential on epidemic size, with case isolation more influential than contact tracing. With 95% of cases isolated, outbreak control can be achieved within 100 days even with only 50% of contacts traced. However, if case isolation and contact tracing both fall to 50%, epidemic control is lost. With a smaller initial attack and a response commencing 20 days after the attack, health system impacts are modest. The requirement for hospital beds will vary from up to 4% to 100% of all available beds in best and worst case scenarios. If the response is delayed, or if the attack infects 10000 people, all available beds will be exceeded within 40 days, with corresponding surge requirements for clinical health care workers (HCWs). We estimated there are 330 public health workers in Sydney with up to 940,350 contacts to be traced. At least 3 million respirators will be needed for the first 100 days. To ensure adequate health system capacity, rapid response, high rates of case isolation, excellent contact tracing and vaccination, and protection of HCWs should be a priority. Surge capacity must be planned. Failures in any of these could cause health system failure, with inadequate beds, quarantine spaces, personnel, PPE and inability to manage other acute health conditions.
规划天花重现疫情需要卫生系统内部具备空间、资源和人员的应急能力。在这种情况下存在许多不确定性，包括攻击的可能性和规模、应对速度以及卫生系统能力。我们使用天花传播模型来确定澳大利亚悉尼在模拟天花疫情中所需的医院床位、接触者追踪和卫生工作者（HCW）数量。我们对攻击规模、应对速度以及病例隔离和接触者追踪比例进行了敏感性分析。我们估计悉尼有 100638 名临床 HCW 和 14595 张公立医院床位。快速响应、病例隔离和接触者追踪对疫情规模有影响，其中病例隔离的影响大于接触者追踪。如果有 95%的病例得到隔离，即使只有 50%的接触者得到追踪，也可以在 100 天内控制疫情爆发。然而，如果病例隔离和接触者追踪都下降到 50%，则无法控制疫情。如果初始攻击规模较小且在攻击发生后 20 天开始应对，那么卫生系统的影响是适度的。在最佳和最差情况下，医院床位的需求将从占可用床位的 4%到 100%不等。如果应对延迟，或者如果攻击感染了 10000 人，那么在 40 天内所有可用床位都将被超过，需要对临床卫生保健工作者（HCW）进行相应的应急增援。我们估计悉尼有 330 名公共卫生工作者，需要追踪多达 940350 名接触者。在最初的 100 天内至少需要 300 万个呼吸器。为了确保充足的卫生系统能力，快速响应、高比例的病例隔离、出色的接触者追踪和疫苗接种以及对 HCW 的保护应该是优先事项。应急能力必须进行规划。这些方面中的任何一个失败都可能导致卫生系统崩溃，出现床位、隔离空间、人员、个人防护设备不足以及无法处理其他急性健康状况的情况。
