Health

Australia’s about-face on masks and Covid-19: why our health advice was late to the party


Can wearing a face mask or covering our nose and mouth protect us from Covid-19 or help stop the disease from spreading?

In the early months of the pandemic, the advice from health authorities to the general public was that while masks could stop sick people from infecting others, there was little evidence that masks protected people who were not sick.

But in recent weeks, that advice has shifted both globally and in Australia.

From Thursday, people in metropolitan Melbourne and Mitchell shire will have to wear a mask or face covering if they’re leaving their home, or face a $200 fine.

Experts have told Guardian Australia that several factors have come together to bring the Victorian government to mandate the use of face masks in public.

Levels of untraced community transmission have gone up, increasing the risk of people becoming infected from interactions with others.

At the same time, scientific evidence has also been published suggesting masks, including non-surgical cloth masks, can suppress the spread of the disease.

One global expert on airborne particles has told Guardian Australia that governments in Australia and elsewhere should have been promoting the use of masks much earlier.

Wearing face masks in public is now compulsory in Melbourne.



Wearing face masks in public is now compulsory in Melbourne. Photograph: William West/AFP/Getty Images

How has the advice on masks changed?

According to the government’s Australian Health Protection Principal Committee, the advice on face masks has remained the same.

People who are not sick don’t need to wear one unless they’re in a place where there is community transmission of the disease.

On April 6, the World Health Organization issued guidance on the use of masks for healthcare workers and for their use in the community.

Studies of flu-like illnesses had shown using a medical mask could stop the wearer from spreading infectious droplets to someone else, or in contaminating the environment around them.

But the WHO said there was no evidence to support the wide use of masks by healthy people in the community. But that advice changed on 5 June.

Days earlier, an article published in leading medical journal the Lancet analysed 172 studies on the impact of physical distancing, face masks and eye protection on infection rates.

The analysis was complex, and came with a string of caveats, but it concluded that wearing face masks likely protects people from infection and that “physical distancing of more than one metre is highly effective and that face masks are associated with protection”.

The WHO issued updated advice on 5 June, saying that “in areas of community transmission” governments should encourage the public to wear non-medical masks.

The agency listed examples where masks were appropriate, such as at grocery stores and schools and when other measures such as physical distancing and contact tracing were harder to control.

The WHO reiterated this advice in a brief issued on 9 July.

Prof. Peter Doherty
(@ProfPCDoherty)

Early advice on masks was unclear, but a lot of work has been done since then. The WHO and the US CDC have been recommending masks since June. They provide both a physical and a psychological barrier. https://t.co/nGwjvEyp9Y https://t.co/tBDsMwYnPz


July 20, 2020

Last week, experts leading the Covid-19 response at the US government’s Centers for Disease Control and Prevention argued now was the time for more widespread and universal use of masks among the community to help slow the spread of the disease.

In an editorial published by the American Medical Association, the experts said there was “compelling evidence that community-wide face covering is another means to help control the national Covid-19 crisis”.

Even homemade masks worn by infected people could limit the “forward dispersion of exhaled respirations”, the article said.

Carrying out detailed studies on the effectiveness of masks would be slow and challenging but, the experts wrote: “It has been persuasively argued the precautionary principle be applied to promote community masking because there is little to lose and potentially much to be gained.”

The CDC experts said as Covid-19 was resurging in the US – as it is in parts of Victoria – “broad adoption of cloth face coverings is a civic duty, a small sacrifice reliant on a highly effective low-tech solution that can help turn the tide favourably in national and global efforts against Covid-19.”

A patriotic face mask.



A patriotic face mask. Photograph: Joel Carrett/AAP

What about advice on masks in Australia?

Prof Lidia Morawska of the Queensland University of Technology says the evidence that masks work to reduce the amount of pathogens people can inhale is well established.

“Saying there’s no evidence [that they can help] was simply wrong,” she said. “The body of evidence about the efficiency of masks has existed long before this pandemic.”

In early March, the prime minister, Scott Morrison, was saying that only infected people needed to wear masks.

Days later, then chief medical officer Dr Brendan Murphy said “there is no reason to put a mask on when you’re walking around the shops”.

By late April, the prime ,inister was noting the advice of the Australian Health Protection Principal Committee (AHPPC) which said wearing face masks for the general public wasn’t being recommended, but this was an option if there was significant community transmission in Australia.

Dr Philip Russo, an associate professor at Monash University and president of the Australasian College of Infection Prevention and Control, said the advice on the wearing of face masks had remained largely the same.

“If you can’t maintain physically distancing, then wear a mask,” he said.

Russo is deputy chair of a group of infection control experts advising the AHPPC and meets every week.

The key change that led to Victoria’s decision to mandate the wearing of masks, Russo said, was the prevalence of infection in metropolitan Melbourne and Mitchell shire.

“Because the prevalence has increased, the likelihood of any interaction has increased – that’s why the government has decided to recommend people wear the masks when they go out for any of those four activities.”

What had also influenced the decision to mandate mask wearing, he said, was emerging evidence that the virus can be spread by people who either have the virus but are showing no symptoms – known as asymptomatic – or people who are not showing symptoms because the virus is in it’s early stages.

“What we know is that the more common route [for transmission] is droplet spread. The droplets that might be propelled will be contained in the mask and won’t be as extensive.

“Where masks will have the biggest impact is in close confined spaces with poor ventilation. If you’re not in a crowd and you’re outside it probably won’t have much of an affect, but in enclosed spaces like trains and buses it will.”

A woman wears a face mask at Bondi Beach in Sydney. People in the city have been strongly encouraged to wear masks.



A woman wears a face mask at Bondi Beach in Sydney. People in the city have been strongly encouraged to wear masks. Photograph: Mark Metcalfe/Getty Images

How can masks protect people who are not sick?

Morawska says when people cough, sneeze or talk, the droplets that are visible to the naked eye tend to fall out of the air quickly.

But she says there are also particles that are too small to see and they can be suspended and moved in the air.

“If they’re in the air we can inhale them and so a mask will reduce that risk. It won’t necessarily remove every single virus from our breathing zone, but it’s likely it removes their concentration so that the dose will not be infectious.”

Morawska says wearing masks puts the responsibility on individuals, but there should also be other measures introduced, including advising that indoor spaces improve ventilation.

She also argues that people should have been told that masks were effective much earlier.

Even if there was a shortage of surgical masks at the time, this should not have been an excuse to “hide this information” from the general public. She said the market would have reacted to fill any shortage of masks.

Victoria’s chief health officer Dr Brett Sutton explaining the recommendations to wear face masks in a video released on July 10.

Dr Hassan Vally, an associate professor and epidemiologist at La Trobe University in Melbourne, says the research published in the Lancet was an important turning point.

Before then, he says, the information in the academic literature on masks and Covid-19 was piecemeal.

“We can be confident that masks work,” he said. “For an intervention that doesn’t cost a lot, anything that reduces your risk is brilliant.”

Don’t forget the other advice

Russo says he is worried some people may feel overprotected by masks and forget the other health advice that governments have worked hard to communicate.

“My concern is that the key message throughout this discussion with masks, is that you still have to perform hand hygiene and keep that physical distancing. Masks alone won’t protect you. There’s a danger people will forget those key messages.”

Vally says the Victorian government’s advice that people can wear any kind of mask or face covering can help remove any anxiety among the population.

“They’re being pragmatic. They’re just giving people as many options as they can because mask wearing is not normalised in our society.

“But this is the right time. Just put something on and you’ll be making a contribution.”





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