Transient models to assess transmission and control of airborne infection risks in a respiratory ward

空气传播是许多疾病的感染途径，包括流感、新冠肺炎和医院里的机会主义病原体。量化风险对于确定适当的控制策略是必要的，无论是在通风等工程方法方面，还是在管理策略方面，如治疗、定位和安排医院患者。然而，空气传播的评估很复杂，因为它需要了解空气流动、感染动力学和人与环境的相互作用。新冠肺炎大流行表明，我们在这一领域非常缺乏知识，特别是关于气流在管理不同大小的空气中颗粒物方面的作用以及不同解决方案的有效性。以前的研究已经开发出将气流和感染动力学联系起来的模型来评估医院环境，包括观察多房间环境中气流模式的影响和小人口中的随机效应。然而，目前的模型一般假设随着疫情的演变，感染参数和气流都是稳定的。该项目旨在探索时间和空间上的瞬时效应的影响，以评估短期事件如何影响个人风险和疫情的整体动态。为此，我们将结合CFD模拟的瞬变气流模型和随机感染动力学模型。这些模型将应用于利兹圣詹姆斯医院的呼吸病房，目的是评估干预措施的有效性，包括空气净化设备的应用。

Airborne transmission is an infection route for many diseases including influenza, COVID-19 and opportunist pathogens in hospitals. Quantifying risks are necessary to determine appropriate control strategies, both in terms of engineering approaches such as ventilation, and management strategies such as treating, locating and scheduling hospital patients. However airborne transmission is complex to evaluate as it requires understanding of the airflows, infection dynamics and human-environment interactions. The COVID-19 pandemic has shown that we have significant lack of knowledge in this area, particularly around the role of airflows in managing different sizes of airborne particles and the effectiveness of different solutions. Previous studies have developed models to link airflow and infection dynamics to assess the hospital environment, including looking at the influence of airflow patterns in multi-room environments and stochastic effects in small populations. However current models generally assume that both the infection parameters and airflows are steady-state as the outbreak evolves in time. This project aims to explore the influence of transient effects in both time and space to evaluate how short term events can influence individual risk and the overall dynamics of an outbreak. To this aim, we will combine transient airflow models from CFD simulations with stochastic infection dynamics models. The models will be applied to the respiratory wards at St James's Hospital in Leeds, with the objective of evaluating the effectiveness of interventions, including application of air cleaning devices.