Advice on mask-wearing to protect against Covid-19

Hip said:
The useful Worldometers website graphically demonstrates the dramatic power of universal wearing of surgical masks to slow down the pandemic:
Click to expand...
You may be right in your deduction, but there were other important differences between these countries too, notably rigorous testing and contact tracing. Also, at least in the case of Taiwan, immediately stopping all people flying in from affected areas, so no continuous stream of new spreaders.

I don't need to tell you that correlation does not imply causation!
 
Trish said:
You may be right in your deduction, but there were other important differences between these countries too, notably rigorous testing and contact tracing.
Click to expand...

Sure, agreed.

I thought about testing being a possible factor, but looking at this graph of testing per capita by country, some countries like Italy and Germany had high levels of testing, comparable to South Korea (although South Korea did more testing in the early stages) :

upload_2020-4-5_17-38-10.png


Although of course testing alone it not the end of it; you also need to do comprehensive contact tracing and quarantining when you find someone is infected.
 
Other countries - I think at least China and S. Korea - also used electronic contact tracing.

Our CDC says we are at a R=1 at the moment, but we don't know which of the measures has had what effect.

We don't know for sure if making wearing masks mandatory would have any effect but from what I understand it would be an easy to implement measure with almost no downsides as long as people know to still keep their distance and only use the non medical ones.

At least I think it's less controversial than using smartphones for tracking which raises many issues regarding data security.
 
Leila said:
We don't know for sure if making wearing masks mandatory would have any effect but from what I understand it would be an easy to implement measure with almost no downsides as long as people know to still keep their distance and only use the non medical ones.
Click to expand...

Yes, it's just commonsense that masks are likely to make a substantial difference. The death toll is 100 times higher in countries which do not use masks for the general populace.

I expect the WHO experts who say masks do not help are probably the type who may understand studies and statistics, but would not know to change a car battery, or fix a leaking tap. That is to say, they've probably got no practical commonsense, just a detached ivory tower perspective.
 
The WHO's advice on masks from yesterday.
  • Suspected or mild cases should wear a medical mask that needs to be changed at least once daily
  • Same for caregivers or household members when in the same room with the infected person.
Possible downsides:
  • false sense of security
  • possible mask shortage for health care workers
  • breathing difficulties
  • self-contaminationby touching and reusing
They stress that

"whatever approach is taken, it is important to develop a strong communication strategy to explain to the population the circumstances, criteria, and reasons for decisions.

The population should receive clear instructions on what masks to wear, when and how (see mask management section), and on the importance of continuing to strictly follow all other IPCmeasures (e.g., hand hygiene, physical distancing, and others)."
 
I have been wearing the mask made by my wife for me today. It is cut from an old seersucker cotton shirt and is easy to wear. I find an important advantage of wearing it is that other people, who might otherwise pass you on a path close by, when they see you wearing a mask, tend to step aside and allow a wide berth. Maybe they think I have the virus! Anyway it seems to have a useful effect beyond just being a barrier.

What seems to me silly is that lots of people say thank you when you stand aside. Since the virus is spewed out when you speak my policy is to raise a hand in a gesture of polite greeting, much as sailors traditionally do. (That probably makes them think even more that I have the virus and cannot even speak.)
 
Leila said:
The WHO's advice on masks from yesterday.
Click to expand...

It seems that the WHO are publishing self-contradictory statements that lack common sense. In that 6 April document they say:
WHO stresses that it is critical that medical masks and respirators be prioritized for health care workers.
Click to expand...
In other worlds, masks are effective and vital for healthcare workers dealing with coronavirus patients, as they prevent viral transmission.

But then according to the WHO, somehow this ability of masks to prevent transmission magically disappears when they are worn by anyone else:
However, there is currently no evidence that wearing a mask (whether medical or other types) by healthy persons in the wider community setting, including universal community masking, can prevent them from infection with respiratory viruses, including COVID-19.
Click to expand...


The WHO are yet not mentioning the unpublished research from Hong Kong which apparently demonstrates the efficacy of masks worn by the general public.
 
It's not contradictory at all, in at least one case.

If you assume that medical staff/healthcare workers are not healthy then it's all consistent.
 
@Hip

I think they focus on close settings (home care, health care) with suspected or diagnosed cases because they want to make sure that medical masks as a (now) limited ressource are reserved for situations where transmission is most likely without one.

When it comes to spread in community settings they leave out the fact that asymptomatic people can transmit, too - but as they often have said in their briefings, they don't think those are the main drivers of the pandemic.*

I too noticed they didn't include studies on non-medical masks in community settings (I think there was not only data from HongKong, but also Taiwan - can't remeber the source though). Maybe the data is not sufficient?

It would be interesting to know though what all these institutions would say if there was, hypothetically, an infinite supply of masks :)

I would prefer they'd say, if that really is the case: We don't have enough so we have to make best use of the limited ones we have.

*this is something I don't understand as viral load in the throat seems to be the highest in the very early (even presymptomatic?) stage of the illness, but that's a question for a different thread
 
Wonko said:
It's not contradictory at all, in at least one case.
Click to expand...

Of course it is contradictory. Obviously masks are vitally important to protect frontline medics, who are surrounded by a high density of infected people in the coronavirus wards and ICUs.

The only difference with the general public is that the density of infected people around them is lower.

But the general public far outnumber frontline medics, so although the chances of transmission are lower for any single member of the public, once you multiply that by the 67 million people in Britain, it's a very different story, and there's a great deal of transmission going on in the general public which could be greatly reduced by wearing masks.


You can argue that there are not enough masks, therefore the WHO has to tell white lies that masks do not protect the general public. But that is foolish, because there are alternatives: one is to do what CDC does, and advise the public to devise improvised masks; the second is to urge governments to greatly ramp up mask production.

The WHO have done neither.
 
If healthy people do not need to wear masks, but medics do, then logically it follows that medics must be not healthy.

Otherwise it's a double standard, and I can't see the WHO doing that sort of thing, when it's their 'job' to look after health on a global basis, it's much more likely that all medics are unhealthy.
 
Wonko said:
If healthy people do not need to wear masks, but medics do, then logically it follows that medics must be not healthy.

Otherwise it's a double standard, and I can't see the WHO doing that sort of thing, when it's their 'job' to look after health on a global basis, it's much more likely that all medics are unhealthy.
Click to expand...

Sorry, I was a bit slow on the uptake of your humour! Yes, I get it!
 
Wonko said:
It's not contradictory at all, in at least one case.

If you assume that medical staff/healthcare workers are not healthy then it's all consistent.
Click to expand...
A not unreasonable assumption, unfortunately.
 
The Face Mask Debate Reveals a Scientific Double Standard

Hilda Bastian
(could be of interest given HB's involment in the Cochrane review)

No one complained about the lack of evidence for 20-second hand-washing. So why did we treat face masks differently?

The recent back-and-forth debate—and policy reversal—over the use of face masks to prevent the spread of Covid-19 reveals a glaring double standard. For some reason, we’ve been treating this one particular matter of public health differently. We don’t see op-eds that ask whether people really need to keep 6 feet away from each other on the street, as opposed to 3 feet, or that cast doubt on whether it’s such a good idea to promote bouts of handwashing that are 20 seconds long. But when it comes to covering our faces, a scholarly hyper-rigor has been applied. In recent weeks, experts have counseled caution—or rejected the use of masks by the general public outright—as they pleaded for better, more decisive evidence. Why?
Click to expand...

https://www.wired.com/story/the-face-mask-debate-reveals-a-scientific-double-standard/
 
Maybe, in our societies, covering our faces also goes completely against our idea of individuality. It's our face that makes us US.

Also, when we communicate we need to see each other's facial expressions and without that we might seem less trustworthy?

2 days ago for the first time I went to a store wearing a mask. I noticed the clerk looking at me in a strange way and even though she was behind a newly put up plexiglass shield at her counter, she stepped back when I entered. Probably thinking I was ill. I wanted to reassure her and smiled - but only realized later that she couldn't have seen that.

It's difficult to show friendlyness only with eyes and voice, I realized.

Outside people also kept more of a distance. It seems, for now, with a mask you make yourself a bit of an outsider, an "untouchable".

Which is good from an infectious point of view but at the same time the idea of interacting without face expressions really is something new for us. Hence the reluctance from our governments?

Maybe I'll get some cloth masks with a friendly pattern.
 
Quite a good account I would say.

I think it is interesting that there is a confusion between the use of a mask to protect oneself and the use of a mask to protect others from oneself. A mask worn by hospital staff is 'PPE' in the sense that it may stop droplets from patients getting on your mouth but surgeons wear masks to protect patients from their own germs. Visors are probably much more relevant to the PPE function.

If home made masks serve the protecting others function well enough then the issue about shortage of hospital masks has been a huge red herring. Masks for controlling spread are not really PPE at all They are OPE - Other-protecting equipment.
 
Sasha said:
An 8-minute section that I've not had time to listen to, from 'More or Less' about whether we should wear masks:

https://www.bbc.co.uk/sounds/play/p0894jhh
Click to expand...

I just listened to this and found it incredibly frustrating because the emphasis seemed to be on, as @Jonathan Edwards said, the use of a mask to protect oneself rather than the use of a mask to protect others from oneself.

My understanding is that the home-made masks don't protect the wearer but protect those around them - so if we're all wearing them, we're all protecting each other.

Why is this point not getting made? Am I wrong about the masks? Why is it that the masks keep virus in but don't keep it out? Is it because it's easier to catch most droplets of whatever size if you're covering up a point-source, but that if virus is in the air it will get into your mouth via the gaps in the home-made mask?
 
You must log in or register to reply here.
Back
Top Bottom