背景:在2021年9月之前,英格兰有55,000-90,000名住院患者被确定为具有潜在的院内SARS-CoV-2感染。这包括可能由于少量或无症状感染而错过的病例。Further,大量的医护人员(HCWs)被认为已经被感染,有证据表明,其中一些案件可能也与医院有联系,同时报告了HCW到HCW和患者到HCW的传播。从SARS-CoV-2大流行开始,在医院进行干预措施,例如在入院时对患者进行测试和戴通用口罩,以阻止患者和HCW人群内部和之间的传播,其有效性在很大程度上是未知的。
方法:使用基于个人的院内传播模型,我们估计了在COVID-19大流行期间,在英国医院实施的整体一揽子干预措施的有效性中,单项干预措施(联合干预措施和联合干预措施)的贡献.感染预防和控制专家小组为干预选择提供了信息,并帮助确保该模型在实践中得到实施。使用国家和地方数据得出模型参数和相关的不确定性,文献综述和专家意见的形式启发。我们模拟了情景,以探索如果未实施干预措施,患者和医护人员可能会看到多少医院感染。我们模拟了从2020年3月到2022年7月的时间段,包括不同的菌株和多剂量的疫苗接种。
结果:建模结果表明,在没有住院测试的情况下,感染预防和控制措施,以及减少入住率和访客,在大流行的过程中,发生SARS-CoV-2医院感染的患者人数可能会高出两倍,仅在第一波中就有超过600,000名HCW被感染。隔离有症状的HCW和HCW的普遍掩蔽是预防患者和HCW人群感染的最有效干预措施。模型发现表明,在英国SARS-CoV-2大流行期间引入的干预措施总体上避免了住院患者中的400,000(240,000-500,000)感染和410,000(370,000-450,000)HCW感染。
结论:干预措施对减少医院感染的传播有不同的影响,但在英国实施的一揽子干预措施显著减少了SARS-CoV-2大流行期间向患者和医护人员的院内传播.
BACKGROUND: Prior to September 2021, 55,000-90,000 hospital inpatients in England were identified as having a potentially nosocomial SARS-CoV-2 infection. This includes cases that were likely missed due to pauci- or asymptomatic infection. Further, high numbers of healthcare workers (HCWs) are thought to have been infected, and there is evidence that some of these cases may also have been nosocomially linked, with both HCW to HCW and patient to HCW transmission being reported. From the start of the SARS-CoV-2 pandemic interventions in hospitals such as testing patients on admission and universal mask wearing were introduced to stop spread within and between patient and HCW populations, the effectiveness of which are largely unknown.
METHODS: Using an individual-based model of within-hospital transmission, we estimated the contribution of individual interventions (together and in combination) to the effectiveness of the overall package of interventions implemented in English hospitals during the COVID-19 pandemic. A panel of experts in infection prevention and control informed intervention choice and helped ensure the model reflected implementation in practice. Model parameters and associated uncertainty were derived using national and local data, literature review and formal elicitation of expert opinion. We simulated scenarios to explore how many nosocomial infections might have been seen in patients and HCWs if interventions had not been implemented. We simulated the time period from March-2020 to July-2022 encompassing different strains and multiple doses of vaccination.
RESULTS: Modelling results suggest that in a scenario without inpatient testing, infection prevention and control measures, and reductions in occupancy and visitors, the number of patients developing a nosocomial SARS-CoV-2 infection could have been twice as high over the course of the pandemic, and over 600,000 HCWs could have been infected in the first wave alone. Isolation of symptomatic HCWs and universal masking by HCWs were the most effective interventions for preventing infections in both patient and HCW populations. Model findings suggest that collectively the interventions introduced over the SARS-CoV-2 pandemic in England averted 400,000 (240,000 - 500,000) infections in inpatients and 410,000 (370,000 - 450,000) HCW infections.
CONCLUSIONS: Interventions to reduce the spread of nosocomial infections have varying impact, but the package of interventions implemented in England significantly reduced nosocomial transmission to both patients and HCWs over the SARS-CoV-2 pandemic.