Abstract View
Measuring the Viability of Airborne Virus under Different Environmental Conditions and Fomites
ROBERT ALEXANDER, Mara Otero-Fernandez, Henry Oswin, Allen E. Haddrell, Jamie Mann, Adam Finn, Tristan Cogan, Andrew Davidson, Richard J. Thomas, Jonathan P. Reid, University of Bristol
Abstract Number: 383
Working Group: Bioaerosols
Abstract
The increasing number of airborne outbreaks worldwide, such as the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, have raised the need to understand parameters affecting the airborne survival of pathogens in order to develop measures for effective infection control. The dynamics involved in the airborne transmission of disease relies on the ability of pathogens to survive aerosol transport and, subsequently, cause infection when interacting with a host. The length of time airborne microorganisms remain infectious in the aerosol phase is a function of a wide range of variables (e.g. atmospheric, microbiological, etc.) that affect their viability and, therefore, have the potential to impact the dissemination of the disease outbreak. Representing the dynamics of airborne disease transmission under laboratory conditions is challenging due to systematic limitations that can impact the accurate representation of the processes that these particles would experience in the natural environment.1
To be presented is the adaption of the CELEBS (Controlled Electrodynamic Levitation and Extraction of Bioaerosols onto a Substrate) technique which has been previously used to study the airborne survival of bacteria.2 The present methodology also enables the robust study of airborne survival of viruses as a function of relevant environmental conditions within a high containment laboratory, using Mouse Hepatitis Virus (MHV) as a surrogate for more pathogenic viruses. The instrument uses piezoelectric dispensers to generate droplets of highly reproducible size and composition, which are then suspended using electrodynamic levitation within a path of temperature and RH controlled air. This technique also presents the ability to subject viruses to airborne transport prior to deposition on surfaces, to better simulate fomite transmission.
Results outlined in this presentation will contribute to understand the impact of several variables such as: (a) relative humidity, (b) temperature and (c) absolute humidity, while featuring some of the benefits of this novel technique including (1) the characterization of the rapid initial decay in viability occurring within the first couple of minutes after aerosolization, representing the importance of close range transmission and (2) the study of airborne pathogens stability on surfaces to accurately simulate the deposition of small particles which have deposited onto a surface after spending time airborne.
[1] Douwes, J., Thorne, P., Pearce, N. & Heederik, D. Bioaerosol health effects and exposure assessment: Progress and prospects. Ann. Occup. Hyg. 47, 187–200 (2003).
[2] Otero-Fernandez, M. et al. Assessing the airborne survival of bacteria in populations of aerosol droplets with a novel technology. J. R. Soc. Interface 16, 20180779 (2019).