EXPERT REACTION: Should masks become mandatory in Melbourne?

In my view, in addition to social distancing, which must stay in place, wearing face masks has the potential to control the spread of infections, as current research studies are pointing towards COVID-19 virus being carried and transmitted via very small particles which can remain in the atmosphere or be pushed further with air currents and probably with air-conditioning systems.

Therefore, it is not only recommended for infected persons to stop the spread of the virus but also to prevent healthy people from getting infected through inhaling the particles carrying the virus. As the focus now is on airborne transmission, in addition to contact transmission, public awareness and clear guidance on the proper and effective use of masks should be considered

Having spent the coronavirus pandemic so far in both Taiwan and Australia, the former with arguably the most evidence-based and successful approach and outcomes, the value of wearing masks is clear. Of course, Taiwan had the experience of SARS, but the public, healthcare professional, governmental and private sector support for masks from the outset was as integral to mitigation of spread and has enabled very low case and fatality rates to be achieved.

It was recognised that the virus could behave in aerosol form through human discharge and especially in polluted atmospheres. It was, and is therefore, necessary to use masks to protect ourselves and others. The advice in Australia has been muddled because this has not been communicated and it is becoming clear that this was because of short supply at first and then the misrepresentation that masks would be of limited value.

Had Australia tackled this issue in a forthright honest way, we would have been able to be less locked down and at less health, societal and economic risk. The greater use of public transport, eating out and education would be examples, as in Taiwan - the unions rightly have been lobbying for  mandatory mask use on public transport. None of this should detract from fastidious personal hygiene and physical (NOT social) distancing.

We can still turn the tide by the public health leadership recommending and overcoming cultural reservation about mask use, and a policy which promotes them with due regard to affordability and sustainable disposability. As with HIV, we may never have a safe and lasting vaccination, and more likely have to optimise our innate immunity, live and socialise in ways that will control aerosol borne infection – by masks or some comparable method, and perhaps need recourse to medication as well.

Additional reference: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30739-X/fulltext?fbclid=IwAR3ssufRJ8vo0wlXeGqfp3K66MbynQH6yvIdVAk_99Qp84z05pqo4jgvO9E

There is good evidence that masks can decrease risk of infection if they are handled correctly, fit well, and are disposed of properly. This is true for COVID-19 in community settings where there is a reasonable risk of exposure, as long as other hygiene and distancing measures are already being used. If wearing a mask, it is important to not fiddle with it whilst it’s on as this may, in fact, increase risk of transmission if you have unknowingly touched contaminated surfaces. Simple cloth masks, washed regularly, are sufficient for healthy people.

We do not currently have levels of virus circulating in the general community to warrant mandatory use of masks, but in areas with high concentrations of positive people, masks may add an extra layer of protection, especially when indoors in shared spaces like supermarkets. This is particularly relevant to people who are in the higher risk categories for more severe illness.

It is important to remember that masks only provide a marginal benefit, and should not make people less cautious whilst wearing them. Anyone with symptoms or a positive test must still stay at home.

The use of standard surgical masks is now recommended when out in the general community, in particular cluster areas and areas such as public transport. However the public needs to be informed about how to use masks.

Masks are single use only. You cannot take a mask off, put it into your pocket to then reapply it again at a later time.

Also you have to assume as you are wearing a mask, the outside of the mask is now infected. Importantly if you have the virus then by definition if you are wearing a mask, the inside of the mask is also infected. Therefore you need to take off the mask without infecting your hands and also not allowing the mask to come in to contact with any surface apart from the rubbish bin that you put it in to. You then have to appropriately wash your hands or use hand sanitiser.

A mask is an adjunct, not the be all end all.

Finally, N95 masks, as opposed to the standard surgical masks, are only recommended in COVID clinical care areas. So if you are caring for someone who has laboratory-confirmed COVID-19, then an N95 mask would be advisable.

To first quote Mary-Louise Mclaws:

'The World Health Organisation released updated guidelines on June 5 acknowledging masks can reduce transmission when physical distancing can’t be maintained or in places of high prevalence. Metropolitan Melbourne is now a place of high prevalence.'

While numbers remain high, wearing a mask or face shield is advisable in high-risk settings, such as public transport. But these give only partial protection, and so social distancing, hand hygiene, and other measures should be maintained.

Most importantly in high-risk settings – see Figure

The evidence on masks is now universally accepted. We know that if worn in the community that they protect others from getting infected if the person wearing one is ill. And they also reduce the risk of being infected by another person if you wear one and are not ill. There is a bit of detail that you need to get across as to which type of masks work best, how to put them on and take them off safely, and some uncertainty about the level of protection, but the important thing is that we know they do reduce the likelihood of the virus being spread.
 
The decision about whether to make the wearing of them compulsory, even though we know that they work, is not straight forward. One has to consider the context, that is, the level of virus circulating in the community and calculate the risk-benefit equation at the population level.

Whilst I am not of the opinion mask-wearing needs to be made compulsory in Victoria, and certainly not in all situations, I feel the community needs more encouragement to wear masks, particularly on public transport, and more guidance on the appropriate use of masks.

I do feel we need to get to a stage where the wearing of masks is more normalised in our society. We need to understand that anything we do to prevent transmission of the virus is useful and a mask is another barrier to infection which can be adopted, in addition to social distancing and hand hygiene, to help us get on top of disease spread.

I think masks use should be mandatory in Melbourne, particularly in high transmission areas/suburbs and public/crowded places.

 We need to understand why we should use masks now. There are two functions of masks in the community – (1) use by healthy people to protect from acquiring infection and (2) used by sick people to prevent the spread of infection (i.e. source control). 

At this stage, local transmission is high in Melbourne and we need masks for both of the above functions, but the main issue is the high proportion of asymptomatic cases of COVID-19. So we don’t know who is healthy and who is sick, so everyone should use mask in high transmission zones.

This is particularly important when you cannot maintain social distancing indoors (gyms, café etc) and going outdoors in crowded settings (public transports, markets).

I am not sure why people are not convinced - this is just another infection control intervention, in addition to isolation of sick cases, quarantine, social distancing, hand hygiene etc.

There is some evidence of airborne transmission of COVID-19 as well, so masks will be good for source control. The cost will not be very high, as people may use cloth masks if medical masks are not available.

In light of the failure of the federal government’s controversial COVIDSafe centralised proximity logging app to offer significant extra post-infection contact tracing capacity in practice, and of the apparent federal promotion of a suppression rather than elimination strategy –– which implies an inevitable consequence of re-opening prior to elimination, and thus exposing people to ongoing risk –– it is important to recognise that we do need to adopt simpler and more foolproof prevention techniques proven to work as the risk increases. From a variety of sources there is evidence that wearing masks appears to be one of these techniques, and so it should be given more prominence, and mandatory use required in certain situations. 
 
Around the world, the experience so far is that post-infection proximity-app-based techniques generally have a low or negligible impact on containing upsurges, notwithstanding the good intentions and high hopes attached to their announcement. If, as many expected, the proximity data apps are not going to deliver a decisive extra order of magnitude of assistance in upsurge response, it may be time to adopt the use of masks. 
 
While some Australians are reluctant to use masks, and they are not a panacea, they do have the benefit (in addition to the clinical effect of reducing the level of certain vectors of transmission) of offering a visual and mental reminder that prevention is a personal as well as a community and government responsibility, whereas there are concerns that apps, and the marketing and branding of them emphasizing ’safety’, may inadvertently risk encouraging a false sense of security in some communities (when they do nothing to prevent infection or warn users of risky proximity) and a lower visibility of the need for actual prevention measures to continue at a significant level.

The efficacy of masks is well understood and it is clear that there are times where masks should be used. Whether this use should be mandatory, voluntary or not recommended is not a question with an easy answer.

There are a number of factors that need to be considered when deciding on what mask to use and when. The type of mask is important. P2/N95 respirators (tight-fitting masks used in health care and other industries for respiratory protection) provide the highest level of protection to the wearer if worn correctly, and many are not. If the P2/N95 mask has an exhalation valve it will not provide protection to others, only the wearer.

Surgical masks (loose-fitting masks used mostly in health care but are the common mask seen in community use) provide a lower level of protection to the wearer but importantly are also useful in protecting others if the wearer is unwell.

Cloth masks (homemade or otherwise) will provide limited protection, however studies have shown they are better than nothing sometimes (it depends on what they are made of).

We then need to consider the level of protection required. SARS-CoV-2 is not being transmitted generally via aerosols requiring airborne protection (this is being debated but Dr Dan Diekema sums up this argument concisely here: http://haicontroversies.blogspot.com/2020/07/a-tiresome-spat.html).  Given this, we would be considering the use of surgical masks for community use.

If we want this to be mandatory then there needs to be enough available for all who we want to wear them to have access. This can and has been a problem. Voluntary use is more manageable but is not enforceable. The next item we need to consider is what is the level of community spread and will mask use impact this? What we have seen overseas (USA and UK in particular) is very widespread community transmission where mask use would limit this.

Here in Australia, it is not so clear. For the wider Australian population mandatory surgical mask use would not be useful. That said, in areas with sustained local transmission surgical mask use may have some use and should be considered by the relevant authorities. Some health services in these areas are already recommending all staff wear surgical masks while at work. I would recommend that in this situation face shields also be considered as there are studies indicating that covering the mouth, nose and eyes further limits transmission. Making use mandatory needs to consider the availability of masks and the ability to enforce use, keeping in mind that to enforce this there needs to be a consequence for not wearing a mask which may fall unfairly on those who cannot access masks if supply is limited/expensive.

There is absolutely no question that universal adoption of mask-wearing in public would reduce the transmission rate of COVID-19. There are multiple studies that demonstrate the effectiveness of this method in preventing viral transmission. The evidence for mask effectiveness comes from laboratory studies as well as epidemiological research in real-world scenarios. Experimental studies demonstrate that masks prevent the spread of airborne droplets that are generated during coughing, sneezing, speaking and even breathing. These droplets are now considered to be a major source of viral transmission. There is also overwhelming evidence from a number of large epidemiological studies that convincingly demonstrate that places where masks are mandatory or commonly used have reduced viral transmission and lower death rates related to COVID-19, compared to places where masks are only worn by a minority of the population at risk.

To be effective in halting the spread of COVID-19 it is imperative that the majority of people wear masks, preferably more than 80 per cent. In one study, it was estimated that if 80 per cent of the population was wearing masks consistently, it would be more beneficial than a strict lockdown. It is a matter of some controversy as to what type of mask is best. The answer may be: the type that is comfortable to wear consistently for prolonged periods of time. N95 masks are the best in protecting against contracting the virus but are not especially comfortable. On a population level, a simple surgical mask or a home-made one is probably sufficient to provide benefit to those who wear them; any mask that covers the wearer’s mouth and nose is better than no mask.

The current outbreak of COVID-19 in Victoria is unlikely to be contained unless universal mask-wearing is made compulsory in public, especially indoors. Out of the three strategies that are effective in reducing the spread of COVID-19, namely: social distancing, handwashing and mask-wearing, it is the widespread wearing of masks that is likely to be most beneficial.