Wu Flu - When, where, and who should be wearing masks?

[Global Warming]

The question: In what contexts are masks effective for preventing and containing the Wuhan Flu? We've all seen the various public statements made by the surgeon general, WHO, and CDC stating that Americans generally should not be wearing masks in day to day life.

However, a number of experts have raised questions about this guidance, for example:

This same section goes on to note that “a medical mask is not required as no evidence is available on its usefulness to protect non-sick persons.” This is not an accurate summary of existing evidence, as there have been trials on the community use of masks by a non-sick person that showed they reduced influenza or flu-like illnesses in the community. These evaluated mixed interventions with hand hygiene and masks and the evidence suggests that when used together they are effective. Commentators have noted that trials that fail to show masks’ effectiveness in protecting wearers may be accounted for by low compliance, which is likely to be a smaller problem in the covid-19 pandemic.


“Individuals with respiratory symptoms” are told in WHO’s guidance that they “should wear a medical mask …” Although there is less evidence to guide us on this specific scenario, it does point towards masks having a benefit for source control. Qualitative research, however, has found that people might avoid this precaution for fear of the stigmatisation and discrimination it might attract. Evidence from patients in China also suggests that asymptomatic patients in the early stages of covid-19 can still infect other people. So how do we ensure that people without obvious symptoms will not infect others? If everyone wears a mask, could it reduce stigmatisation and discrimination, and help to achieve the goal of source control? As asymptomatic “virus shedders” may be fuelling community transmissions, the widespread wearing of masks could be an effective method of source control.


Relatives or caregivers to individuals with suspected covid-19 who have mild respiratory symptoms are told that they “should wear a medical mask when in the same room with the affected individual.” This recommendation would seem to indicate that wearing a medical mask can protect the wearer. It is backed up by some evidence of how to prevent household transmission.

One fairly common theory is that this is part of a strategy to discourage people from hoarding masks, preserving the supply for health care workers and others with a more critical need for this type of PPE. If this is indeed the case, is this justifiable from an ethical perspective? Is it at all effective, given the numerous reports from January onward of PPE in the US being bought and shipped to China or Europe?

Edit: A couple additions, the CDC is apparently reconsidering their guidance on mask-wearing as of March 30, and there's a neat website advocating #Masks4All with quite a few additional resources for that side of the argument.

Let's try to keep this thread tightly focused on this specific topic, as general Wu Flu discussion and news can go in the other one. It's rather difficult to have an in-depth discussion there, since it moves quite quickly.

 

[Husky_Khan]

It'd probably be more of masks can prevent infection if there were enough of them out there. But there ain't so the public health types emphasized social distancing, hand washing and everyone having gloves since they don't want mask hoarding and amplifying shortages.

Unless lots of people wear masks properly it ain't going to mitigate much anyhow.

 

[Duke Nukem]

The question: In what contexts are masks effective for preventing and containing the Wuhan Flu? We've all seen the various public statements made by the surgeon general, WHO, and CDC stating that Americans generally should not be wearing masks in day to day life.

However, a number of experts have raised questions about this guidance, for example:



One fairly common theory is that this is part of a strategy to discourage people from hoarding masks, preserving the supply for health care workers and others with a more critical need for this type of PPE. If this is indeed the case, is this justifiable from an ethical perspective? Is it at all effective, given the numerous reports from January onward of PPE in the US being bought and shipped to China or Europe?

Let's try to keep this thread tightly focused on this specific topic, as general Wu Flu discussion and news can go in the other one. It's rather difficult to have an in-depth discussion there, since it moves quite quickly.

I bought a respirator mask a few weeks ago, probably won't help but whatever it makes me feel safer .

 

[Global Warming]

It'd probably be more of masks can prevent infection if there were enough of them out there. But there ain't so the public health types emphasized social distancing, hand washing and everyone having gloves since they don't want mask hoarding and amplifying shortages.

Unless lots of people wear masks properly it ain't going to mitigate much anyhow.

Yeah, we certainly don't have the mask-wearing culture of some Asian countries, but some people wearing masks ought to be better than none. And a surprising number of people are, at least in the DC area. I went to a grocery store the other day, and eyeballing it, roughly a third of the people I saw had some sort of mask. At this relatively early stage of the spread in the US, anything that flattens the curve now will pay significant dividends down the road.

 

[Doomsought]

Unless the mask covers your eyes, the only use for the mask is to keep your sneezes from infecting other people.

 

[Deleted member]

Masks should be worn at all times except when you are occupying a room by yourself. Period. They keep you from touching your face (directives to just "not do it" are absurd and impossible for most people to follow), they protect others around you from aerosol exhalation, and they provide marginal protection against direct inhalation of aerosols being blown onto you by someone else who does not observe social distancing. Everyone should be wearing a surgical mask or equivalent at all times at this point, again, except when in a room alone by yourself.

 

[Global Warming]

Unless the mask covers your eyes, the only use for the mask is to keep your sneezes from infecting other people.

Even assuming that's the case, from a community health perspective, that's pretty useful. The majority of cases seem to have minimal or zero symptoms, and those are the people more likely to continue going about their business rather than self-isolating. The more people wearing masks in public, the lower the r0 will be.

 

[Deleted member]

Unless the mask covers your eyes, the only use for the mask is to keep your sneezes from infecting other people.

That's not the case at all. The eyes are only a secondary infection route and not a very good one, and even glasses present aerosols from reaching them at roughly the same level a surgical mask does. Protection is always a matter of degrees, and there's been so much absurd fearmongering about this virus.

 

[Global Warming]

Masks should be worn at all times except when you are occupying a room by yourself. Period. They keep you from touching your face (directives to just "not do it" are absurd and impossible for most people to follow), they protect others around you from aerosol exhalation, and they provide marginal protection against direct inhalation of aerosols being blown onto you by someone else who does not observe social distancing. Everyone should be wearing a surgical mask or equivalent at all times at this point, again, except when in a room alone by yourself.

I mostly agree with this, but I think it's a bit unrealistic to expect people to wear masks even when with members of their household. For people with a spouse and/or kids, that means wearing a mask most of the time, even when at home. That's a much bigger ask than encouraging people to wear a mask when they leave the house (which should be minimized at the moment anyways, especially with many states putting into place stay at home protocols).

 

[BF110C4]

Ok, so not a perfect solution, but good enough to decrease the chances of contagion at a minimal expenditure of resources now that the industry is mass producing masks anyway.

And talking about making your own masks, is cotton a good enough fabric? For casual wear (as in going out for 30 minutes and then take it off at home) it is possible to wash and reuse and which cleaning agents are recommended in that case?

 

[Bacle]

Masks should be worn at all times except when you are occupying a room by yourself. Period. They keep you from touching your face (directives to just "not do it" are absurd and impossible for most people to follow), they protect others around you from aerosol exhalation, and they provide marginal protection against direct inhalation of aerosols being blown onto you by someone else who does not observe social distancing. Everyone should be wearing a surgical mask or equivalent at all times at this point, again, except when in a room alone by yourself.

For outside activities or shopping, definitely. Even a scarf or bandana around the mouth and nose helps to some degree for those.

But in your house around family, it probably is rather a moot point. At that point, unless you are going full NBC gear in the home already, it's likely too late to keep from being exposed.

Simpler, and more cost effective with limited amounts of cleaning supplies, to treat the home as a sterile area and sterilize things as before/just after they enter.

Now, if you are in a home with someone who is symptomatic/already positive, and they are properly isolated, that guideline about masks may help keep others from getting infected.

I mostly agree with this, but I think it's a bit unrealistic to expect people to wear masks even when with members of their household. For people with a spouse and/or kids, that means wearing a mask most of the time, even when at home. That's a much bigger ask than encouraging people to wear a mask when they leave the house (which should be minimized at the moment anyways, especially with many states putting into place stay at home protocols).

This.

It's simply not realistic to expect people to wear masks around the house indefinitely. Particularly when the mask supply is most being directed to medical professionals and first responders.

 

[Deleted member]

@Bacle while I respect that, we find that the infection rate for people in close contact has only been about 10%, so getting people to wear masks in the house would be a benefit.

 

[Duke Nukem]

I don't know about wearing masks at all times, But it's definitely a good idea to wear one when your going out for essentials .

 

[Global Warming]

Ok, so not a perfect solution, but good enough to decrease the chances of contagion at a minimal expenditure of resources now that the industry is mass producing masks anyway.

And talking about making your own masks, is cotton a good enough fabric? For casual wear (as in going out for 30 minutes and then take it off at home) it is possible to wash and reuse and which cleaning agents are recommended in that case?

My understanding is that after use, you can seal a mask in an airtight bag and leave it for a week or so, after which it should be safe to reuse (less time at a higher temperature). So really, you should be able to get by with a handful of masks, assuming only occasional errands.

 

[Bacle]

@Bacle while I respect that, we find that the infection rate for people in close contact has only been about 10%, so getting people to wear masks in the house would be a benefit.

In an ideal world, yes.

However, it is not a realistic expectation. Particularly if no one in the home is symptomatic, and the other guidelines are being followed. Even following the other guidelines can be, for an average person's stockpiles, pushing it with supply shortage issues.

We need to give realistic advice, not ideal dictates.

My understanding is that after use, you can seal a mask in an airtight bag and leave it for a week or so, after which it should be safe to reuse (less time at a higher temperature). So really, you should be able to get by with a handful of masks, assuming only occasional errands.

Also, microwaving heavy-duty latex gloves (think dishwashing gloves) for reuse can help stretch cleaning/sanitation supplies.