Authorities are scrambling to figure out how a security guard in his 20s was infected with coronavirus despite wearing personal protective equipment during his shifts at a quarantine hotel.
It comes as health experts across Australia plead for the Australian government to update all COVID-19 guidance to emphasise the risk of aerosol transmission.
An open letter from Health Care Workers Australia has demanded “national action on aerosol transmission of COVID-19”, claiming essential workers in Australia are “wearing poorly fitted surgical masks, which do not afford any satisfactory level of protection against airborne pathogens in high-risk environments.
“This has led to infections in these workers and spread into the wider community, resulting in large outbreaks with major economic and social disruption,” the group warned.
Last night, Perth was plunged into a five-day lockdown after it emerged the hotel quarantine security guard had tested positive for COVID-19. The man had been to a large number of locations without knowing he had the virus.
Premier Mark McGowan held an emergency press conference on Sunday afternoon, revealing WA’s first locally acquired case in almost 10 months. Urgent contact tracing is now under way.
He said the guard had been working at Four Points by Sheraton in the CBD where there were four active cases, including two of the UK variant and one of the South African mutant strain.
The Maylands resident had tested negative on January 15, 17 and 23 but developed symptoms on Thursday, January 28.
Mr McGowan said it was suspected the man had the highly contagious UK variant as he had worked on the same floor as a case of that strain.
But authorities are now trying to understand just how he contracted the virus, with WA Health Minister Roger Cook confirming man “would have” been wearing personal protective equipment at the hotel.
“Something did go wrong and we do need to get to the bottom of it,” Mr Cook said.
Mr McGowan and health officials will spend the coming days attempting to piece it together, confirming on Sunday that “exactly how the infection was acquired remains under investigation”.
“We suspect he contracted the illness on the Tuesday or the Wednesday,” the Premier told reporters.
“We are advised that he may have been a driver for one of the rideshare companies.
“The last day he worked in the hotel was Wednesday, but we are advised, and this is being carefully followed up, that he did not do any other work in the time since.”
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THIS ISN’T THE FIRST TIME
Virus outbreaks through hotel quarantine has become a familiar story in Australia.
Last month, Queensland health authorities scrambled for answers over how six existing cases of the UK’s highly infectious strain were linked to the same quarantine hotel, the Hotel Grand Chancellor, despite having no contact.
At the time, Queensland’s Health Chief Dr Jeannette Young admitted that authorities were “struggling” to find out how the virus escaped and spread so quickly, while Queensland Premier Annastacia Palaszczuk said the only known connection between those infected at the Hotel Grand Chancellor was that they were on the seventh floor.
“Both groups of these overseas arrivals stayed on the same floor of the hotel at different times but not in neighbouring rooms,” she said.
Health authorities were already stumped on how a cleaner at the hotel contracted the virus, but the last two cases, a man and his daughter who arrived from Lebanon, sparked fear over the rate of transmission and how the virus is moving around.
Dr Young said she “doesn’t understand how it’s happened on floor seven”, and suggested the virus could have travelled throughout the hotel.
“We’ve seen in other states there’s been transmission from one floor, missed a floor, then down to the next floor, and they haven’t been able to work out how.
“So now that we’ve had two separate transmission events, I think we have to be very cautious.
“We don’t know how they’re linked in terms of spread from one person to the next. We just know that in some way this has happened,” she said.
Speculation centres on aerosol spread or airborne transmission, where infection spreads through exposure to virus-containing respiratory droplets that can remain suspended in the air over long distances and time (typically hours), according to the US Centres for Disease Control and Prevention (CDC).
“The particles are small enough to stay suspended in air. They can be transmitted at significant distances – that means room to room,” occupational and environmental physician David Allen told the ABC.
The Australian Government’s Infection Control Expert Group (ICEG) in October last year said it “consistently recognised the potential for transmission of SARS-CoV-2 via aerosols in specific circumstances”.
“These droplets can also land on objects or surfaces so the virus is transmitted through contact with a contaminated surface or object.
“Experts agree there is a gradient from large droplets to aerosols, however, those who have been in close or direct contact with a COVID-19 case are at highest risk,” it wrote.
While the group acknowledged the virus can spread in this way through “clinical care”, there is no such guidance for hotel quarantine.
The World Health Organisation has warned that ventilation is an important factor in preventing the virus from spreading.
“Recirculated air from split airconditioning units, fan coils or any system that runs with a recirculation mode should be avoided where possible, unless in a single occupancy room with no one else present,” it said.
“If recirculation is unavoidable, increase outdoor air exchange by opening windows, if possible and safe to do so, and minimise air blowing from one person directly at another.”
In November last year, University of Adelaide adjunct professor of architecture Geoff Hanmer and University of Technology Sydney Faculty of Science emeritus professor Bruce Milthorpe wrote in The Conversation: “COVID-19 is much more likely to spread indoors rather than outdoors.”
The pair noted the CDC warns the risk of catching COVID-19 indoors is 18.7 times higher than in the open air.
“Commonwealth authorities were still playing down the significance of airborne transmission,” they warned.
HEALTH EXPERTS PLEAD FOR CHANGE
At the time of the Queensland outbreak, a group of doctors wrote to the Queensland Government pleading for airborne disease specialists to become involved in investigations.
The group, including cardiologists and anaesthetists, suggested using aerosol scientists, occupational hygienists and a heating, ventilation and airconditioning expert to help piece together the puzzle.
“We believe experts from these three fields have an important role to play in elucidating the cause of viral spread both within the hotel and in future planning for all hotel quarantine around Australia, and could piece together an important piece of this puzzle for the nation,” they said in the letter.
Australian Institute of Occupational Hygienists president Kate Cole said: “We need to engage technical specialists to look at the indoor air quality in ventilation inside these facilities and understand if that has been a key contributing factor, because we believe it’s highly likely that it is.”
Meanwhile an open letter from a large group of Australian health care workers have demanded “the most urgent measures to reduce the risk of workers at the international border and in hotel quarantine becoming infected”.
The group, which included emergency doctors and university professors, said the government must “make the most urgent measures to reduce the risk of workers at the international border and in hotel quarantine becoming infected”.
Professor Lyn Gilbert told the ABC the ICEG would “be updating advice” after meeting last month.
The advice was being updated “particularly in light of the arrival of the highly transmissible UK COVID-19 variant”.
– with Rebecca Le May, NewsWire