Use of portable air cleaners to reduce aerosol transmission on a hospital COVID-19 ward

A/Prof. Caroline Marshall1,2,3, A/Prof Kirsty Buising1,2,3, Associate Professor Robyn Schofield2, Professor Louis Irving1, Melita Keywood4, Ashley Stevens1, Nick Keogh1, Grant Skidmore2, Imogen Wadlow2, Kevin Kevin2, Behzad Rizmanchi2, Amanda Wheeler5, Ruhi Humphries4, Associate Professor Marion Kainer6, Associate Professor Forbes McGain6, Professor Jason Monty2

1The Royal Melbourne Hospital, Melbourne, Australia
2The University of Melbourne, Melbourne, Australia
3Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
4Commonwealth Scientific and Industrial Research Organization, Melbourne , Australia
5Australian Catholic University, Melbourne, Australia
6Western Health, Melbourne, Australia

Introduction

It is now accepted that COVID-19 can be spread via the airborne route. Hospital ventilation systems are largely designed for comfort and many areas may not be suitable for managing patients with airborne infections. We traced airflow in a COVID-19 ward and tested the effectiveness of commercially available air cleaners in reducing airborne particle concentrations.

Methods

Testing was performed in a ward which had previously housed COVID-19 patients. The return air vent for the whole ward is just inside the single entrance and exit point. Glycerine-based aerosol was used as a surrogate for respiratory aerosols. The transmission of aerosols from a single patient room into corridors and a nurses’ station in the ward was measured. The rate of clearance of aerosols was measured over time from the patient room, nurses’ station and ward corridors with and without air cleaners (also called portable HEPA filters).

Results

Aerosols rapidly travelled from the patient room into other parts of the ward. Air cleaners were effective in increasing the clearance of aerosols from the air in clinical spaces and reducing their spread to other areas. With two small domestic air cleaners in a single patient room of a hospital ward, 99% of aerosols could be cleared within 5.5 minutes.

Conclusion

Air cleaners may be useful in clinical spaces to help reduce the risk of healthcare acquired acquisition of respiratory viruses that are transmitted via aerosols. They are easy to deploy and are likely to be cost effective in a variety of healthcare settings.


Biography:

Associate Professor Marshall is an infectious diseases physician at the Royal Melbourne Hospital where she is also Head of the Infection Prevention and Surveillance Service. She is also Principal Research Fellow in the Department of Medicine at the University of Melbourne. She has been part of the senior management team managing the COVID-19 outbreak at the Royal Melbourne Hospital.

Date

Nov 08 2021
Expired!

Time

3:25 pm - 3:45 pm

Local Time

  • Timezone: America/New_York
  • Date: Nov 07 2021
  • Time: 11:25 pm - 11:45 pm