Linking SARS-CoV-2 Aerosol Viability and Environmental Factors in Healthcare Settings

项目总结/摘要 来自呼吸道感染患者（如COVID-19和流感）的病毒雾化是一个主要的 这些病毒可能会使医疗保健人员（HCP）和患者处于 感染这项研究的基本原理是，虽然流行病学研究已经确定了一些医疗保健 由于这些活动对HCP构成高风险，并且这些活动被认为会产生气溶胶， 关于气溶胶中传染性病毒的浓度和大小分布的信息有限。结果它 仍然很难确定气溶胶生成的医疗保健活动，并区分那些造成高 对HCP和患者的风险。这项研究的长期目标是防止病毒性疾病的传播 通过呼吸气溶胶。提出了三个目标。目的1是开发和评估一种尺寸选择性 评估气溶胶中活病毒的方法。市售的尺寸选择性入口满足基于健康的 将对采样惯例进行评估，以便与一种创新的仪器--活病毒气溶胶采样器一起使用 （VIVAS，气溶胶装置公司），与参考气溶胶和噬菌体MS 2。目标2是表征 一种或多种方法可用于测量由医疗保健活动产生的活病毒气溶胶的浓度和尺寸分布。 Aim 1的入口将与传统的气溶胶采样设备一起部署，以测量选定的 活病毒，大小选择的病毒遗传物质，以及房间内的气溶胶数量和大小分布， 流感或COVID-19患者。将研究六项医疗保健活动，每项活动有6-9项COVID观察结果- 19例患者和6-9例流感患者的观察结果。这些活动将根据初步的 15项活动的气溶胶特征。目标2的主要假设是呼吸的方差 气溶胶在医疗保健活动中比在医疗保健活动中更大，并且在 这意味着某些活动产生的气溶胶比其他活动更多或不同。次级 目的2的假设是，呼吸道气溶胶中病毒基因拷贝与活病毒的比率不 在医疗保健活动内部或之间存在差异，如果是这样，这意味着活病毒浓度可能 从PCR结果可靠地推断。目的3是将气溶胶特性与患者、手术和环境联系起来 特色目标3的主要假设是呼吸气溶胶特性的变化 由环境、患者和医疗保健活动特征解释，相对于 在医疗保健活动中，这反映了环境和患者的有限变化 由于本研究在医疗机构中的表现， 住院病人。通过这项研究产生的知识将大大增强我们的理解 呼吸道气溶胶中的病毒所带来的风险。感染预防专家将能够利用这些知识， 教育医护人员，并选择控制策略，使医护人员能够安全有效地执行他们的工作。的 这项研究的成果将是针对气溶胶生成活动的循证感染预防做法。

PROJECT SUMMARY/ABSTRACT Aerosolization of viruses from patients with respiratory infections, such as COVID-19 and influenza, is a major concern in healthcare because these viruses can put healthcare personnel (HCP) and patients at risk of infection. The rationale for this study is that while epidemiology studies have identified some healthcare activities as posing a high risk to HCP and these activities are thought to generate aerosols, there exists very limited information about the concentration and size distribution of infectious virus in the aerosol. As a result, it remains difficult to identify aerosol-generating healthcare activities and to distinguish those that pose a high risk to HCP and patients. The long-term goal of this research is to prevent the transmission of viral diseases through respiratory aerosol. Three aims are proposed. Aim 1 is to develop and evaluate a size-selective method to assess viable virus in aerosol. Commercially available size-selective inlets meeting health-based sampling conventions will be evaluated for use with an innovative instrument, the Viable Virus Aerosol Sampler (VIVAS, Aerosol Devices, Inc.), with reference aerosols and bacteriophage MS2. Aim 2 is to characterize the concentration and size distribution of viable virus aerosol generated from healthcare activities.One or more inlet from Aim 1 will be deployed alongside conventional aerosol sampling equipment to measuresize-selected viable virus, size-selected virus genetic material, and aerosol number and size distribution in rooms with influenza or COVID-19 patients. Six healthcare activities will be studied, each with 6-9 observationsfor COVID- 19 patients and 6-9 observations for influenza patients. These activities will be selected based on preliminary aerosol characterization of 15 activities. The primary hypothesis of Aim 2 is that the variance in respiratory aerosol is greater among healthcare activities than within healthcare activities, and does not vary between viruses, which implies that some activities generate more or different aerosol than others. The secondary hypothesis of Aim 2 is that therethe ratio of virus gene copies to viable virus in respiratory aerosol does not vary within or among healthcare activities, which, if true, means that the viable virus concentration can be reliably inferred from PCR results. Aim 3 is to link aerosol properties to patient, procedure, and environmental characteristics. The primary hypothesis of Aim 3 is that the variance in respiratory aerosol characteristics explained by environmental, patient, and healthcare activity characteristics is small relative to variation within and among healthcare activities, which reflects that limited variation in environmental and patient characteristics are expected owing to the performance of this research in a healthcare facility and among hospitalized patients. The knowledge generated through this research will greatly enhance our understanding ofthe risks posed by viruses in respiratory aerosol. Infection preventionists will be able to use this knowledge to educate HCP, and to select control strategies that permit HCP to perform their jobs safely and efficiently. The outcome of this research will be evidence-based infection prevention practices for aerosol-generating activities.