Danish study shows no significant reduction of Covid-19 in wearers of surgical masks

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Do we need a scientific consensus that a mask that covers the mouth and nose slows down the spread of a RESPIRATORY virus?

When we're making laws, doling out punishments, and people are making potentially life&death decisions about it yes. I'm not saying change all behavior because one study came out but certainly finding out how effective they are in different scenarios is worthwhile.
 
I wear a mask when I'm out and about, it's very rare to see someone without a mask around here. I think compliance is very high, at least where I am. Yet we are in a spike of covid cases once again.

I will say, I was at the supermarket 2 days ago, there was a lady, who was masked, who looked ill, hacking up a lung. I heard another guy, same thing. People need to stay home when they are sick.
 
The idea is that the mask takes the velocity out of the air, or at least redirects the stream away from the person you're talking to, thus reducing the chance of virons reaching them.

I'm aware of what the prevailing thoughts are behind masking. Whether or not they are statistically effective at doing so is sort of the crux of the argument, isn't it?
 
I wear a mask when I'm out and about, it's very rare to see someone without a mask around here. I think compliance is very high, at least where I am. Yet we are in a spike of covid cases once again.

I will say, I was at the supermarket 2 days ago, there was a lady, who was masked, who looked ill, hacking up a lung. I heard another guy, same thing. People need to stay home when they are sick.

I often develop a cough certain times of year when the air turns cool/dry or during various allergy seasons. Usually just a couple of coughs and the itch is scratched. I'm used to it but now as crazy as everyone is over this virus I get a bit self conscious. I can't be the only one.
 
I haven’t read this whole thread but I’ll post my experience.

A month ago I was piloting a survey flight with myself and two observers in a 172. A few hours after we landed one of the observers got sick and tested positive. We all had masks on. Myself and the other observer never got sick. That and the fact my dad is currently in the hospital with lungs that are trying to heal is reason enough for me to mask up.


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The metaphor is accurate. It was at the 5th grade level. If you did not get it, it's because you don't want to get it and you have a political agenda. Ridiculous coming from a person with your education and on a pilot forum. But again, that is why 2000 Americans will die today. Sad.


Disagree on the metaphor being accurate.

Again, that have 0 comorbidity issues or not?

I know why you ignored the question the first time, but figured I would ask again.
 
I often develop a cough certain times of year when the air turns cool/dry or during various allergy seasons. Usually just a couple of coughs and the itch is scratched. I'm used to it but now as crazy as everyone is over this virus I get a bit self conscious. I can't be the only one.

I have allergies, and I cough occasionally. This poor lady almost had a death rattle, I am not exaggerating.
 
So far the only people I have heard singing the absolute praises of masks and degrading those that question their effectiveness are laymen.

People educated in the medical sciences beyond the level of basic primary care all seem to have very different opinions than the layperson.

I find it even more amusing when high functioning educated people with no knowledge of the subject matter degrade, insult and shame those that do.

where is @Ted It’s time to start calling people children again.
Then why do doctors wear masks? They obviously wear better (N95) and better fitting masks (fit tested) when around respiratory disease patients. If doctors are so smart and they all apparently know masks are not necessary, why are they wearing them?
 
Then why do doctors wear masks? They obviously wear better (N95) and better fitting masks (fit tested) when around respiratory disease patients. If doctors are so smart and they all apparently know masks are not necessary, why are they wearing them?

Same reason we have the TSA?
 
So... this image is posted in response to a thread created by a multi-degreed, extremely well-read and literate authority, whether or not you agree with his interpretations? That says quite a bit about ... well... lots of things. Perhaps if the above image were captioned, "If the Black Plague happened in 2020, Politicians: Do what we tell you ... People in the US: Umm.. That's not why we built this country".... of course, the image would have to be changed 'cause licking rats wouldn't make sense... not that it does now, or that it's an even remotely accurate representation of ANY attitude present today that I'm aware of.
But it’s true....multi-degreed specialists in infectious diseases told people to stay home and wear masks and they didn’t. They had “corona parties” and large weddings, and big church events, and drank at crowded bars.
 
But it’s true....multi-degreed specialists in infectious diseases told people to stay home and wear masks and they didn’t. They had “corona parties” and large weddings, and big church events, and drank at crowded bars.

And then you have people that wear masks and get it anyway. So again, if you're scared, get an 8 mil plastic bag and a zip tie. It will guarantee you won't spread it. I mean we want guarantees right?
 
So how could that be one way? Just imagine two people in a room, one infected and the other not. Why would it matter who wore the mask?
If both people wore masks, then you would multiply the effectiveness. If the first mask caught only 50% of the particles, the second mask also catches 50% of the particles, you only have 25% as much transmission as opposed to the 50% with one mask. If the masks each stop 80%, than two masks result in 5 times lower particle transmission.
 
@PeterNSteinmetz I am quite disappointed that you have taken this tack. I would think that with your training and obvious intelligence you could combine a bit of common sense along with some science. Let's try this:
  1. any kind of mask will provide a physical obstacle to pathogens leaving the oronasal area.
  2. any kind of mask will decelerate most aerosols leaving the oronasal area.
  3. surgical masks have a long history of protecting people from illness. They are standard issue in any surgical theater.
  4. given that a surgical mask can protect an open wound less than a meter away, one would think that they could be protective at two meters
  5. there are plenty of studies suggesting masks do prevent viral transmission, some which I've linked on this site. Are you perhaps participating in a bit of confirmation bias?
If you really think masks are ineffective at transmitting viral disease you should stop wearing them in the OR. And yes, I'll be more than happy to not be one of your patients.

By the way guys, most MD PhDs are the cream of the crop. Most of these guys get their med school for free, but have to be that much smarter than everyone else. Moreover, they have to get their doctoral research done on an accelerated schedule. I have been deeply impressed with every last one I've met.
 
Same reason we have the TSA?

Hey, Siri: Define “knee-jerk reaction”.

...shows me a pic of a TSA agent wearing a mask.

Government doesn’t know what to do? Create mandates. Feeeeeeeels good.


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But it’s true....multi-degreed specialists in infectious diseases told people to stay home and wear masks and they didn’t. They had “corona parties” and large weddings, and big church events, and drank at crowded bars.

and since everyone one of "those people" who didn't wear masks spread the virus.... oh wait.

It is as if people think that the virus will spontaneously generate in the absence of a mask.
 
It also presumes that people are catching it from others in public in situations
Hey, Siri: Define “knee-jerk reaction”.

...shows me a pic of a TSA agent wearing a mask.

Government doesn’t know what to do? Create mandates. Feeeeeeeels good.


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Sheeple feel better if someone is telling them they will protect them and rules demonstrate that something is being done.
 
It also presumes that people are catching it from others in public in situations

Sheeple feel better if someone is telling them they will protect them and rules demonstrate that something is being done.
And people who are ignorant will feel better being ignorant regardless of the facts.
 
And people who are ignorant will feel better being ignorant regardless of the facts.

Matt/Raw power: You should stay home and stay safe.

Problem solved. You’re welcome.


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Matt/Raw power: You should stay home and stay safe.
Problem solved. You’re welcome.
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I was just responding to Salty talking to “sheeple”. I was not pointing to anyone in particular either. Just talking to those that may be ignorant, whoever they may be.

I didn’t tell you what to do, so don’t tell me what to do.

Problem solved. You’re welcome.
 
If both people wore masks, then you would multiply the effectiveness. If the first mask caught only 50% of the particles, the second mask also catches 50% of the particles, you only have 25% as much transmission as opposed to the 50% with one mask. If the masks each stop 80%, than two masks result in 5 times lower particle transmission.

That is true and a good observation. But what I am interested in in this discussion with MuseChaser is whether there is any evidence that the effect is asymmetric. I think that is interesting because that would need to be true to some large extent for the results in the Danish study to be true and for there to be a significant source protection effect in the general population.
 
That is true and a good observation. But what I am interesting in in this discussion with MuseChaser is whether there is any evidence that the effect is asymmetric. I think that is interesting because that would need to be true to some large extent for the results in the Danish study to be true and for there to be a significant source protection effect in the general population.
I have always lamented the poor mask choices and poor fit of most peoples’ masks. Better fit will catch and filter better and this is where a lot of the gains could be made.
Personally I wear KN95 or N95 masks when in confined spaces and surgical masks when outside on trails or in parks. But it took a few different styles to find well fitting versions that you can tell actually seal well and could possibly pass an OSHA fit test.

obviously a bandana is not going to work well in either direction compared to a well fitting purpose made mask designed to filter in either direction.
 
Based on your posts, you’re in the mask-shaming business. No?

Do you support mandates?


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I support science. Science shows that there are hundreds of thousand of “excess deaths” this year, with even the now highly partisan CDC saying that most are from COVID. Oh, and look, it was written by MDs and PHDs
https://www.cdc.gov/mmwr/volumes/69/wr/mm6942e2.htm
Lauren M. Rossen, PhD; Amy M. Branum, PhD; Farida B. Ahmad, MPH; Paul Sutton, PhD; Robert N. Anderson, PhD
Summary
What is already known about this topic?

As of October 15, 216,025 deaths from COVID-19 have been reported in the United States; however, this might underestimate the total impact of the pandemic on mortality.

What is added by this report?

Overall, an estimated 299,028 excess deaths occurred from late January through October 3, 2020, with 198,081 (66%) excess deaths attributed to COVID-19. The largest percentage increases were seen among adults aged 25–44 years and among Hispanic or Latino persons.

What are the implications for public health practice?

These results inform efforts to prevent mortality directly or indirectly associated with the COVID-19 pandemic, such as efforts to minimize disruptions to health care.
 
Not being advisable or just not necessarily being effective? IOW are masks actually said to be pernicious? (No, I'm too lazy to read the studies.)

I meant that a public mask mandate is likely not advisable. That is for a variety of reasons. They are discussed in further detail in the editorial which is on my medical interest page. Probably should leave it at that generally as it borders on political tradeoffs.

From a purely medical perspective, there is some evidence that health care workers wearing cloth masks are more likely to catch respiratory illnesses (MacIntyre et al 2015 doi:10.1136/ bmjopen-2014-006577).
 
From a purely medical perspective, there is some evidence that health care workers wearing cloth masks are more likely to catch respiratory illnesses (MacIntyre et al 2015 doi:10.1136/ bmjopen-2014-006577).
And that is why you certainly don’t see many doctors wearing cloth masks at work these days.

If we had enough N95 masks for everyone to wear them for just 2 weeks back in April, we may have been able to control at least the first wave.
 
If we had enough N95 masks for everyone to wear them for just 2 weeks back in April, we may have been able to control at least the first wave.

I understand that is reasonable speculation. And it is also true that it might have just made the later number of cases larger. Hard to say. My speculation is that this will run its course in one or two seasons regardless of any interventions short of vaccination or the natural achievement of herd immunity. These viruses are highly evolved to spread and under considerable evolutionary pressure to find a way.

But the really core question regarding mask mandates is what is the evidence the a mask mandate which orders the general public to wear some kind of face covering will help slow the spread of Covid-19. If the majority will wear cloth masks, due to unavailability and comfort, and cloth masks cause an increase in respiratory infections, I imagine you can see how it might not help the situation even from an infectious disease or mortality perspective.
 
Dodged that question I see.


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Well, science also supports the mandates that prevented all (as in zero cases) community spread of COVID in New Zealand for more than 3 months this summer after they had and followed strict mandates. And they have a total of 5 deaths per million people where as we have 789 deaths per million people (and rapidly rising).

The virus existed in their population and on their island. If it was inevitable for it to spread unchecked, how do you explain their experience this summer? Because of strict mandates (and a population willing to listen to competent leaders) they were able to eliminate it from their population for 100 days until the virus was reintroduced through travel, shipped goods, or other methods. During those 100 days, the entire population was able to resume their normal lives with no risk to anyone at all. With more mandates, they will be able to keep their death rates to a figure 100-200 times (not percent) less per capita than the USA, while also allowing their population to freely congregate at the times when the virus concentration is sufficiently low.
 
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I think empirically we are seeing what this study claims, it's just not PC to acknowledge that what is being demanded by politicians and others is not nearly as effective as they claim it is.

Unfortunately we are saddled with a highly contagious virus that spreads easily. While masks may help to some small degree, they are not stopping the spread of this virus. Let's hope these new vaccines coming quickly work.

To be fair, the motto hasn't been "Stop the Spread" - it has been "Slow the Spread". Slow the rate of infection long enough to get vaccines and more understanding of what we're dealing with to combat it properly.
 
To be fair, the motto hasn't been "Stop the Spread" - it has been "Slow the Spread". Slow the rate of infection long enough to get vaccines and more understanding of what we're dealing with to combat it properly.

That is absolutely a fair assessment, I agree and wish people would remember this. Unfortunately a just read a post in another thread where some one made it sound like those who get infected by this virus are at fault because of their poor decisions.
 
To be fair, the motto hasn't been "Stop the Spread" - it has been "Slow the Spread". Slow the rate of infection long enough to get vaccines and more understanding of what we're dealing with to combat it properly.
We had a chance to do much better back in April. And also see my post above about New Zealand. I know they are an island and smaller than the US, but it shows that you can stop a highly contagious virus. It is not inevitable that it will spread to everyone. You just have to not put your head in the sand early on in the pandemic. And have competent leaders, and listen to those leaders, and follow the mandates correctly, not just when you feel like. If all of those things are done, then real progress is made. If the population/leader decides to do whatever they want, regardless of mandates/science, the virus wins every time.
 
@PeterNSteinmetz I am quite disappointed that you have taken this tack. I would think that with your training and obvious intelligence you could combine a bit of common sense along with some science. Let's try this:
  1. any kind of mask will provide a physical obstacle to pathogens leaving the oronasal area.
  2. any kind of mask will decelerate most aerosols leaving the oronasal area.
  3. surgical masks have a long history of protecting people from illness. They are standard issue in any surgical theater.
  4. given that a surgical mask can protect an open wound less than a meter away, one would think that they could be protective at two meters
  5. there are plenty of studies suggesting masks do prevent viral transmission, some which I've linked on this site. Are you perhaps participating in a bit of confirmation bias?
If you really think masks are ineffective at transmitting viral disease you should stop wearing them in the OR. And yes, I'll be more than happy to not be one of your patients.

.

Well, this actually made me research the "Why? behind the use of masks during surgery.

My resulting understanding is it is primarily about blocking bacteria/liquid droplets from getting into the wound and keeping liquid from the patient infecting the medical personnel. It did not seem to be about stopping viral transmission.

It also led me to the following that seems to question if the masks are effective in that capacity.

https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD002929.pub3/full

Item 3 in your list rings of "Its always been done that way" without understanding the "Why?", never a strong foundation for a decision.
 
That is absolutely a fair assessment, I agree and wish people would remember this. Unfortunately a just read a post in another thread where some one made it sound like those who get infected by this virus are at fault because of their poor decisions.
Unfortunately, some of those people are at fault for doing blatantly dangerous things like drinking all night in a crowded bar in North Dakota.
 
We had a chance to do much better back in April. And also see my post above about New Zealand. I know they are an island and smaller than the US, but it shows that you can stop a highly contagious virus. It is not inevitable that it will spread to everyone. You just have to not put your head in the sand early on in the pandemic. And have competent leaders, and listen to those leaders, and follow the mandates correctly, not just when you feel like. If all of those things are done, then real progress is made. If the population/leader decides to do whatever they want, regardless of mandates/science, the virus wins every time.

I also happen to completely agree with this sentiment. Health should not be a political issue, especially during a pandemic. Wearing a mask isn't fun, but I do it because it's not about me or how I feel about it. I like to be out and about as much as the next guy and I'm not doing that either. I'm listening to the people who have dealt with virology and disease for decades longer than I've been alive.

I am disappointed so many other people in this country can be so selfish and irresponsible and push us farther into this pandemic. People that can't render the cognitive dissonance of believing that it'll all just "go away" and everyone will "stop talking about it after the election" while it continues to get worse and worse. People that don't care about what's happening until it happens to someone they care about.
 
I also happen to completely agree with this sentiment. Health should not be a political issue, especially during a pandemic. Wearing a mask isn't fun, but I do it because it's not about me or how I feel about it. I like to be out and about as much as the next guy and I'm not doing that either. I'm listening to the people who have dealt with virology and disease for decades longer than I've been alive.

I am disappointed so many other people in this country can be so selfish and irresponsible and push us farther into this pandemic. People that can't render the cognitive dissonance of believing that it'll all just "go away" and everyone will "stop talking about it after the election" while it continues to get worse and worse. People that don't care about what's happening until it happens to someone they care about.
I am young (but live with and take care of my dad who just finished pancreatic cancer chemo). But....My airport is full of guys at high risk, average age 70+. A few (3-5ish out of 80) caught it in April-May and got lucky. A wife in the hospital for 3 days, some bad fevers. But now they mostly feel invincible and there are not many masks to be found and they get together quite often. So it seems like it is a race against time this winter to see whether the vaccine gets here or another infection that spreads through the rest of them.
 
Danish study finally out. NO significant difference in infection rate between those wearing surgical masks and those who do not.

"Our results suggest that the recommendation to wear a surgical mask when outside the home among others did not reduce, at conventional levels of statistical significance, the incidence of SARS-CoV-2 infection in mask wearers in a setting where social distancing and other public health measures were in effect, mask recommendations were not among those measures, and community use of masks was uncommon."

This is rather consistent with the prior randomized trials on masks and the seasonal flu as well.

https://www.acpjournals.org/doi/10.7326/M20-6817
Reread carefully what you quoted: "…in a setting where social distancing and other public health measures were in effect…"

In other words, nothing new here. When it's possible to maintain 2m distancing consistently and there is freshly-circulating air (e.g. outside, or somewhere with good ventilation), transmission is highly unlikely, which is exactly what the WHO, CDC, and other public-health experts have been saying since March.

On the other hand, if you're somewhere like a grocery store or an office, where you might sometimes have to stand or pass closer than 2m (call it 6 ft) from other people, masks help: the Oxford study concluded that where distancing wasn't possible, home-made masks reduced the risk of transmission by 4× if just the infected person was wearing a mask, and 6× if both the infected person and the uninfected person was wearing a mask.
 
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Unfortunately, some of those people are at fault for doing blatantly dangerous things like drinking all night in a crowded bar in North Dakota.
Sometimes, yes, but many others are suffering because of someone else's bad decision. It's the same as influenza — I get the flu shot not because I'm worried about myself (I'm 56 and healthy), but because I don't want to pass the virus to someone else, who then passes the virus on to someone else who's vulnerable and might die from it. Just because I never know who I might kill with selfish and irresponsible behaviour doesn't mean it wouldn't happen. We need to take care of each-other.
 
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