In his second note on the political economy of the imminent Covid-19 pandemic, Dr Yannis Gourtsoyannis looks at the antinomies of facemasks
You may have noticed that there seems to be at least one highly visible cultural difference between "Eastern" responses to Covid19 and "Western" responses - the use of face masks by ordinary people in public spaces. Face mask use seems to be more socially prevalent in the East. Why?
Of course, for the time being, the burden of Covid-19 is much greater in the East; and we are indeed seeing more face mask use in Europe; as case numbers rise here too. However, I do think that some discrepancy in mask use between say the UK and China will remain - even if the pandemic hits the UK and even if a substantial proportion of the population starts wearing them here. The other possibility is that we too will start wearing masks en-masse. I think that it would be interesting to explore the determinants of whether or not that happens.
The question that arises is; should general members of the UK public start ordering their own masks? Should I be hurriedly buying up potentially lucrative shares in UK mask-manufacturers or snaffling away face masks from my hospitals supply cupboard? (Not that I would ever partake in either of those activities anyway!).
Firstly let's look at what we know for sure about facemasks and the clinical contexts in which they are crucial.
Masks are a core component of Personal Protective Equipment in the hospital setting. When I look after patients with suspected bacterial infections of a certain sort (such as TB) or suspected viral infections of a certain sort (such as MERS) I wear one.
In general, if the risk of transmission and disease is relatively low for a specific pathogen (more to say on that, but beyond the scope of this post) then I simply need to prevent big droplets from coughing patients hitting my face. A simple surgical mask can be acceptable.
But surgical masks were not designed to protect health workers from patients. They were designed to protect surgical patients from surgeons.
So if I'm dealing with concerning pathogens (even when the patient is not coughing) or if I'm doing certain aerosol generating procedures then I need to wear a different mask; an FFP3. These masks prevent aerosol transmission of infection. They have a special filter and they need to be specially fitted.
Basically both kinds of masks are crucial stock in any hospitals stock cupboard. Doctors need them to protect themselves and ultimately their patients. I use them in my job fairly frequently.
However, there is no evidence that the PUBLIC use of face masks does anything to mitigate an outbreak to any significant degree. There is also no good evidence that it reduces the risk for any given individual trying to protect themselves from something like Covid19.
Consider a scenario: you are on crammed public transport, commuting to work in the context of a significant Covid-19 oubreak..
There is potentially aerosolised virus all around you.
In this scenario:
- If you DON'T have the virus there is no point in wearing a surgical mask to protect yourself; the virus aerosol will pass through the mask or around it.
- If you DO already have the virus then sure, you may slightly reduce the risk of passing it on to others by using a surgical mask.
Now take the FFP3 mask:
- If you DON'T have the virus then an FFP3 mask may protect you.
- If you DO have the virus then the FFP3 mask filter can actually result in increased transmission to others. Not good.
Add to the above the fact that: we know that the vast majority of people do not put their masks on properly, that this is inevitable if wearing for long periods of time, that plenty of viral transmission occurs via fomites (infected surfaces) anyway, and that there's plenty of transmission between family members or work colleagues...
Do you see the complexity arising here?
Therefore, from a purely public health perspective mask-wearing cannot be recommended because, in short: masks cannot be a substitute for the CORE principles of infection control:
- Quick identification, isolation and management of cases on the part of the authorities.
- Good hand hygiene, good cough etiquette (coughing into the crook of your elbow) and prompt self-isolation if ill...i.e the duties of individual members of the public.
That's why Public Health England recommends against using masks outside clinical settings. They are likely to have little overall effect on an outbreak.
Furthermore, as I have already hinted - there are some theoretical risks/harms of wearing masks (imagine how yucky some of them get after a few days) and I already touched upon how FFP3 masks can increase transmission in certain conditions.
But there are wider, societal-level risks too. In China, partly due to Government enforcement of mask-wearing we are seeing an unprecedented demand for masks. Supply is struggling to keep up. The cost of buying a mask is rising. A black market of second-hand or faulty masks is emerging. Class differentials are becoming evident: those who are poorer and unable to afford masks are subjected to punitive measures and significant constraints on their freedom to a much greater degree than those richer or better connected than themselves.
Also, mask shortages are hitting precisely those places where they are needed (in hospitals). This is because market forces are skewing the flow of masks in the direction of those who don't need them (the general, asymptomatic public). We already know that hospitals can be amplifiers of serious viral outbreaks. Hospital staff are massively more at risk of contracting and passing on the virus. So a hospital mask shortage is no joke.
The Chinese government seems to be taking steps to mitigate these market phenomena (which have partly arisen due to their own decisions) by taking on a duty to provide masks to their citizens.
So, that's the science of it all; I won't be stocking up on masks if the pandemic hits the UK. I will simply be buying a few bottles of hand sanitiser and maintaining good hand hygiene and cough etiquette.