Exploring the Factors that Determine the Survival of Viruses in Aerosols and Droplets

探索决定病毒在气溶胶和飞沫中存活的因素

• 批准号: BB/W00884X/1
• 负责人: Jonathan Reid
• 金额: $ 71.08万
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FW00884X%2F1
• 关键词: Exploring; Factors; Determine; Survival; Viruses

The transmission of microbes which cause disease between humans, such as bacteria and viruses, can occur by direct (person-to-person), indirect (contact with contaminated surfaces) and airborne routes. Small aerosol particles of a respirable size (<10 micrometres diameter) and larger droplets (up to 100 micrometres, about twice the diameter of a human hair) can remain airborne for minutes to hours and are emitted by coughing, sneezing, speaking and breathing. Larger droplets settle very quickly over short distances contaminating surfaces (referred to as fomites). Although the transmission of some diseases, such as tuberculosis and measles, show preferential airborne transmission, other diseases, such as influenza and norovirus, are opportunistic. Identifying both the circumstances when these different modes of transmission are dominant and clarifying ways to mitigate them must be priorities. Such knowledge informs the implementation of non-pharmaceutical interventions, such as physical distancing and the use of appropriate personal protective equipment such as face masks. Further, the clinical context sees the wide use of many aerosol generating procedures that are poorly understood but could carry pathogens through the air, for example in dental procedures and in anaesthesia. Despite the recognised importance of aerosols and droplets in the transmission of microbes, the evidence-base on which decisions are made to mitigate microbe transmission often remain epidemiological. Robust innovative instruments for studying the factors that control the survival of pathogens in aerosols, droplets and fomites are crucial to move our understanding forward. Using a novel technology platform developed at the University of Bristol, we will deliver a comprehensive framework for understanding the factors that control the survival of the virus SARS-CoV-2, the cause of COVID-19 in aerosols, droplets and fomites. We have developed a bespoke system to study how well microbes survive in aerosols and droplets containing microbes referred to as CELEBS. We will study the interactions between the SARS-CoV-2 virus (in respiratory droplets) and its immediate environment in a recently commissioned state of the art facility. By levitating a known number of aerosol droplets of identical size with a known viral load for a specified period of time, the survival of the virus will be measured and the impact of inactivation measures studied. More specifically, we will fully explore the survival of the SARS-CoV-2 virus in droplets of varying size exposed to varying environmental conditions (relative humidity and temperature) and in realistic simulated fomites deposited on surfaces. We will also explore the influence of light and atmospheric oxidants (open air factor) and the rate of dynamic changes in particle size and moisture content upon droplet/aerosol generation (i.e. desiccation/drying kinetics on exhalation). The survival of different variants of the SARS-CoV-2 virus will be examined. This project will build on preliminary work that has confirmed and validated our experimental approach. This more comprehensive work will provide clarity to inform non-pharmaceutical interventions such as social distancing, recommended indoor operating temperatures and humidities (e.g. hospitals, care homes, transport) and other methods of inactivation (e.g. light and oxidants). Extending beyond these immediate studies, the technique will be flexible, opening up opportunities to study a wider range of important airborne pathogens.

引起人类疾病的微生物，如细菌和病毒，可以通过直接（人与人之间），间接（接触污染表面）和空气传播途径传播。可吸入尺寸的小气溶胶颗粒（直径<10微米）和较大的液滴（高达100微米，大约是人头发直径的两倍）可以在空气中停留几分钟到几个小时，并通过咳嗽、打喷嚏、说话和呼吸排出。较大的液滴在短距离内非常快速地沉降，污染表面（称为污染物）。虽然某些疾病的传播，如肺结核和麻疹，显示出优先的空气传播，其他疾病，如流感和诺如病毒，是机会性的。必须优先查明这些不同传播方式占主导地位的情况，并澄清减轻这些传播方式的方法。这些知识有助于实施非药物干预措施，如物理距离和使用口罩等适当的个人防护设备。此外，在临床环境中，看到了许多气溶胶生成过程的广泛使用，这些气溶胶生成过程知之甚少，但可以通过空气携带病原体，例如在牙科过程和麻醉中。尽管气溶胶和液滴在微生物传播中的重要性已得到公认，但做出减轻微生物传播决定的证据基础往往仍然是流行病学。研究控制气溶胶、液滴和污染物中病原体存活的因素的强大创新仪器对于推动我们的理解至关重要。利用布里斯托大学开发的一个新技术平台，我们将提供一个全面的框架，以了解控制病毒SARS-CoV-2存活的因素，SARS-CoV-2是COVID-19在气溶胶，液滴和污染物中的原因。我们开发了一个定制的系统来研究微生物在含有微生物的气溶胶和液滴中的生存情况，这些微生物被称为CELEBS。我们将在最近委托的最先进的设施中研究SARS-CoV-2病毒（在呼吸道飞沫中）与其直接环境之间的相互作用。通过悬浮已知数量的相同大小的气溶胶液滴（具有已知的病毒载量）一段指定的时间，将测量病毒的存活率，并研究灭活措施的影响。更具体地说，我们将充分探索SARS-CoV-2病毒在暴露于不同环境条件（相对湿度和温度）的不同大小的液滴中以及沉积在表面上的真实模拟污染物中的生存。我们还将探讨光和大气氧化剂（露天因素）的影响和动态变化的速度，在液滴/气溶胶的产生（即干燥/干燥动力学呼气）的颗粒大小和水分含量。将检查SARS-CoV-2病毒不同变种的存活情况。该项目将建立在已经证实和验证我们的实验方法的初步工作的基础上。这项更全面的工作将为非药物干预提供清晰的信息，例如社交距离，推荐的室内工作温度和湿度（例如医院，护理院，运输）以及其他灭活方法（例如光和氧化剂）。除了这些直接的研究之外，该技术将是灵活的，为研究更广泛的重要空气传播病原体开辟了机会。

项目成果

Mucin Transiently Sustains Coronavirus Infectivity through Heterogenous Changes in Phase Morphology of Evaporating Aerosol.

• DOI: 10.3390/v14091856
• 发表时间: 2022-08-24
• 期刊: Viruses
• 作者: Alexander RW;Tian J;Haddrell AE;Oswin HP;Neal E;Hardy DA;Otero-Fernandez M;Mann JFS;Cogan TA;Finn A;Davidson AD;Hill DJ;Reid JP
• 通讯作者: Reid JP

Differences in airborne stability of SARS-CoV-2 variants of concern is impacted by alkalinity of surrogates of respiratory aerosol.

• DOI: 10.1098/rsif.2023.0062
• 发表时间: 2023-06
• 期刊: Journal of the Royal Society, Interface

Oxidative Stress Contributes to Bacterial Airborne Loss of Viability.

• DOI: 10.1128/spectrum.03347-22
• 发表时间: 2023-03-13
• 期刊: Microbiology spectrum
• 影响因子: 3.7

The microphysics of surrogates of exhaled aerosols from the upper respiratory tract

上呼吸道呼出气溶胶替代物的微物理学

• DOI: 10.1080/02786826.2023.2299214
• 发表时间: 2024
• 期刊: Aerosol Science and Technology
• 影响因子: 5.2
• 作者: Tian J