Earlier this year, a group of healthcare workers and scientists wrote an open letter to the APPHC and other groups, including the Prime Minister, calling for national action on aerosol transmission.
Strengthening prevention and control
The Department of Health responded to the 350 national and international signatories, saying it understood there to be “little clinical or epidemiological evidence of regular airborne transmission of SARS-COV-2,” based on advice received.
Reporting this letter in the Medical Journal of Australia in April, Dr Zoë Hyde, epidemiologist with the University of Western Australia, and her colleagues, said the evidence was compelling and sufficiently strong to warrant the immediate strengthening of Australia’s infection prevention and control guidelines.
In one example there was an outbreak in a South Korea apartment complex where only residents living in apartments connected by a common ventilation shaft were infected. An investigation found no other possible contact between the cases than the airborne infection through a single air duct in the bathroom.
Hyde advocates for a national quarantine standard, as does Professor Brendan Crabb, director and chief executive of the Burnet Institute.
“Right through last year, the dogma in the infectious disease world was that the virus was spread by respiratory droplets but the science has moved on and that is outdated and wrong. Most quarantine leaks we’ve had, have clearly or probably been due to air particles,” Crabb says.
National standard needed now
”While the federal government deserves a lot of credit in this pandemic, it’s got this blind spot. We need leadership and solidarity on this issue because it’s the crucial missing piece. The government is inching towards accepting this but it needs to rush forward and embrace it.”
Crabb says a national standard should be smart and able to evolve. “Once established, more nuanced approaches to minimising virus entry could be trialled and adopted. In the medium term, a traffic light system assessing risk, home-quarantine, and home-based testing are all possibilities to work together with “airborne ready” quarantine for higher risk travellers. Along with a high rate of vaccination, this will be the only way to allow more people in while keeping the virus out.”
Without a national standard, a hotel breach in one city could cause an outbreak in another, as just happened in Melbourne.
In April, chief medical officer Professor Paul Kelly said of course aerosols play a part, but were not the key, to transmission.
On Friday, the Department of Health said the potential of transmission via aerosols has been consistently recognised and evidence for it, continues to be reviwed. Similar to other respiratory viruses, it says evidence indicates COVID-19 is mainly transmitted by respiratory droplets and that there is a gradient from large droplets to aerosols.
“The potential for aerosol transmission is higher under certain conditions such as poorly ventilated indoor crowded environments.”
Australia’s Infection Control Expert Group, which advises the government on COVID-19, was recently criticised for underestimating the threat of airborne transmission. One of its subgroups has reported on the issue and country is now waiting for updated guidelines on mitigating airborne transmission.
As it waits, concern about quarantine is growing because dangerous variants are emerging and mixing with each other. Some hybrids travel at speed through the air, like the one now sweeping Vietnam.
Critics dispute the Australian government’s assertion that the quarantine system is 99.9 per cent successful and that leaks are inevitable.
Inadequate hotel ventilation
In The Conversation this week, three experts from the University of Melbourne outlined their analysis showing for every 204 infected travellers in Australian hotel quarantine, there is one leak.
They identified 21 failures between April 2020 and June 2021 in Australia, with 4.9 failures per 1000 positive cases in quarantine.
Dr Driss Ait Ouakrim, Ameera Katar and Professor Tony Blakely, of the Centre for Epidemiology and Biostatistics, said risks associated with shared spaces and inadequate ventilation in hotels had been known for 10 months and had been consistently highlighted.
This had little impact, with May’s federal budget providing no new funds for purpose-built facilities beyond an already-announced expansion at Howard Springs, in the Northern Territory, increasing its capacity to 2000 from 850.
The three academics – like so many others – repeated the mantra that every state and territory should have a Howard Springs-style facility. With its single-storey cabins, outdoor verandas and separate airconditioning systems, it has had no leaks.
While lower-risk arrivals could go into hotels, those at higher risk could go to the safer facilities.
This week saw a significant shift in quarantine. On Wednesday, key government adviser Jane Halton expressed disappointment at how the government had failed to adopt “best practice right across the system”.
Eight months ago, the National COVID-19 Co-ordination Commission Advisory Board released a review calling for additional national quarantine facilities. As commissioner, Halton was perplexed it had taken so long to expand the Howard Springs facility and back a proposal for a purpose-built facility in Victoria.
On Thursday, the government acted and announced backing for a Victorian facility at a site near Avalon airport. Details are yet to be released.
Morrison says no to Wellcamp
Queensland Premier Annastacia Palaszczuk repeatedly urged the federal government to “plan for the future” and create regional quarantine, saying city hotels are not suitable.
Her government considered a private proposal for a facility near Wellcamp airport on the outskirts of Toowoomba, but Prime Minister Scott Morrison said it was not viable and the proposal was threadbare.
While federal endorsement is still needed, South Australia has approved a plan to allow international students to return and quarantine at Parafield Airport in units that house students learning to fly.
In West Australia, Rottnest Island is being reconsidered as a quarantine destination, as are building hubs in Busselton or Exmouth that have airports with international capacity.
This state wanted to use existing immigration detention centres or military bases, but the Commonwealth didn’t agree.
NSW is yet to announce its plans.
Although the lockdown in Victoria and leaks in WA and SA have roused people from COVID-19 complacency, there is a growing belief that the pandemic is tapering and will soon end.
It won’t. Professor Michael Toole an international health specialist at the Burnet Institute, says Australians need just look to their neighbours. Taiwan, credited with putting in a gold standard performance, is now under viral assault. Its quarantine held beautifully for 250 days until it leaked at the Novotel Taipei Taoyuan International Airport. Now, the country is dealing with 400 cases a day.
He says Australia has had a scattergun approach to quarantine. “I’ve looked at all the five mainland capital cities and there’s huge variation in effectiveness. I’d say WA, Queensland and NSW are behind Victoria and South Australia which have, at least, conducted ventilation audits.
“There’s been absolutely no systematic learning of the lessons from breaches in hotel quarantine. The APPHC should take one day off, not talk about vaccination and focus intensely on quarantine.
“We can manage without legislation and make do with consensus among these health professionals because they are the quarantine managers. A national code that prevents, or at least minimises, airborne transmission is essential.
“It’s well beyond time for forceful measures to prevent airborne transmission that includes rigorous ventilation audits followed by remedial action and the provision of effective N95 respiratory masks.”
When Toole surveyed the world for quarantine facilities, he found few, and none as good as Howard Springs.
“Quarantine is a highly neglected area. At the luxury end, Malta offers seaside villas so attractive that after their 14 days, many travellers rebook for better times. At the bleaker end, military installations are used together with hotels in Vietnam.”
Australia’s abundance of space allows for sprawling quarantine facilities, although Toole says they need to be near hospital facilities and appropriate airstrips.
Experts agree that an effective quarantine system would be legacy infrastructure for Australia. This will be crucial if the world is, as many fear, truly entering a “pandemic era”.