The outbreak of COVID-19 at a restaurant in the southern Chinese city of Guangzhou was a puzzle.
The suspected index patient was a visitor from the coronavirus’s epicentre in Wuhan. But the eight other customers who later tested positive were not sitting close enough for droplet transmission, and most of the patrons and staff avoided infection altogether.
According to the National Post, a team of local scientists eventually came to an eye-opening conclusion about the episode: tiny particles of virus had hitched a ride on currents created by the eatery’s air-conditioning.
To read the entire National Post article, click here.
That runs counter to the prevailing view that the novel coronavirus is transmitted only by heavier “droplets.” But for a group of civil engineers at the University of Alberta, the finding was no surprise. In their world, they say, it’s well known that building ventilation systems are efficient disseminators of viruses and other pathogens, and they believe the COVID-19 bug is no exception.
Aided by a $440,000 federal-government grant, they’re now working on ways that buildings could change their HVAC set-ups to curb the risk of infection, what the researchers call a “non-pharmaceutical” intervention against the disease.
Australian and Chinese air quality experts who have had experience with SARS, another coronavirus, argued in a paper that as droplets from an infected person start to evaporate, the resulting smaller particles can indeed become airborne.
“It is highly likely that the SARS-CoV-2 virus also spreads by air,” they conclude, urging “all possible” action in response, including modifications to ventilation systems. “We predict that… failure to immediately recognize and acknowledge the importance of airborne transmission and to take adequate actions against it will result in additional cases.”
(National Post)
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