COVID-19: New focus on indoor ventilation needed

A group of leading virologists have explored how COVID-19 has redefined our understanding of airborne transmission, and the need for improved indoor ventilation, for the British Medical Journal.

Dr Julian Tang, Honorary Associate Professor at the University of Leicester and Clinical Virologist, worked with colleagues from Virginia Tech, the University of Hong Kong, and Edinburgh Napier University to compare current guidance with recent studies into how the SARS-CoV-2 virus is transmitted.

They advise that, given ‘the virus transmits mostly between people at close range through inhalation’, the risk of surface transmission of COVID-19 is much less significant than previously thought.

However, the group have expressed the need for added emphasis on ventilation since the smallest suspended particles – even produced by simply talking or breathing – can remain airborne for hours.

The World Health Organisation (WHO) released updated guidance in March to improve the provision of indoor ventilation.

Dr Tang explained: “Many of us were concerned about the aerosol transmission of this virus at a very early stage, based on early studies on reported outbreaks in China:

“These early warning signs were not heeded by many western countries in their infection control precautions against COVID-19. 

“Earlier control, including masking and improved ventilation, of the virus spread in hospitals and the community, as we saw with early, universal masking in many Southeast Asian countries, could have saved tens of thousands of lives as indicated by one of several models.”

Improved indoor ventilation could also bring further benefits – reducing transmission of other respiratory viruses such as the common cold, as well as environment-related complaints such as allergies and so-called ‘sick building syndrome’.

The full paper ‘COVID-19 has redefined airborne transmission’ is published in the British Medical Journal.