Usage of Masks “Flattened” Growth of Coronavirus Cases in Czech Republic | Hacker News Reader

Usage of Masks “Flattened” Growth of Coronavirus Cases in Czech Republic

praguemorning.cz

62 pointslxm94 comments

I will not be surprised if mask usage becomes normalized in Western cultures after this, just as happened in Asian cultures after SARS.

Not in the USA. The government is still telling people masks don't do anything.

The idea will probably lodge itself in our minds, but in practice there are no masks to buy, so we can't even start getting used to it.

We could improvise them though. I know in Hong Kong they have asked people to improvise using layered paper towels and tissues because those are readily available nonwoven fabrics.

It isn't as good as the real thing, but done at the population level I expect it would lower the reproductive value of the virus and thus help flatten the curve.

> improvise using layered paper towels and tissues because those are readily available nonwoven fabrics.

sorry is there a youtube video for this. Just want to make sure i don't make a mistake.

Yes there is: https://www.consumer.org.hk/ws_en/news/specials/2020/mask-di...

Experts devise do-it-yourself face masks to help people battle coronavirus:

https://www.youtube.com/watch?v=aNjpH5lBZ8w

I imagine that just like my grandparents who lived through the Depression hoarded ketchup packets despite being financially secure, as soon as N95 masks are freely available I will keep a stash handy for the rest of my life, regardless of whether I ever face another pandemic, or official organizations advise against it.

That is exactly why I already had masks. I've kept a small stash since the Ebola epidemic.

One intriguing question that I can't answer today is whether or not this global pandemic is the exception, or whether 100+ years without a global pandemic is the exception.

Not to mention, you look out over the next 50-100 years, you gotta be concerned about biological warfare. Having a population that knows how to handle a pandemic keeps the non-science-fiction viruses at bay pretty well.

But we had influenza pandemics in 1957 and 1968, plus the swine flu in 2009...

You can make your own cloth mask.

I don't know, people in the US seem to be pretty stubborn. I think people feel that being asked to wear a mask is somehow "un-American"

"People in the US" isn't a useful category for thought on this matter. There are subcultures where I find the idea that they will ever wear masks routinely risible. There are subcultures where I could easily see it becoming absolutely de rigueur with social consequences for non-compliance. You and I probably have different ideas about what those subcultures are, but for this post it would simply suffice to say that there would be different reactions.

I tried to give away cloth masks (not medical masks) to people in my area and nobody wanted one, and I live in a very liberal, highly educated part of the country. I'm hoping this attitude can be changed, I'm just pointing out that there seem to be some uniquely American psychological issues associated with mask wearing that need to be taken into account.

Well... this is why I said "you and I probably have different ideas about what those subcultures are". With my priors, "liberals" not wanting to wear masks doesn't surprise me at all.

Consider watching something like https://www.ted.com/talks/jonathan_haidt_the_moral_roots_of_... , and then ask yourself: Which groups would you expect to accept and even enforce mask wearing, and which will reject it?

Thanks for the link to the video. Wouldn't ultra conservatives wear masks because of 'Ingroup', 'Authority', 'Purity', and only when it becomes law? Wouldn't ultra liberals wear masks because of 'Harm', 'Fairness', as it becomes clear scientific consensus? Thanks

I would wear a mask I bought from a reputable vendor. I would not wear a mask given out on the street by someone I never met. Maybe it's a matter of trust and not attitude or education.

Just launder the mask.

There have been doctors in the US in TV, articles, etc that have been recommending people not to wear masks. Doctors who work/worked for CDC, not just random doctors. Some say it's because masks don't work. Some say don't because Americans don't know how to wear masks properly. There have even been doctors saying masks will make spreading/getting infection easier.

People are probably just following their advice and once the advice switches, they will probably follow that advice too.

I live in Austin and people are wearing masks here.

It’s not about being “un-American”, which is ridiculous just for the mere fact that not wearing masks in public is a western country thing, not just an American thing. The reason it’s not culturally acceptable is because, in western countries, wearing a mask in public is like wearing a big “warning: I’m toxic” sign, precisely because we haven’t had to deal with these fucked up super viruses that Asian countries are used to.

You have a point on the "West" thing, however Austria, Chzech republic, and UK have already instituted mandatory mask use in some circumstances.

So it took a government mandate, and then only in "some circumstances." Not exactly indicative of a cultural shift just yet.

At this point you might actually find a good number of people, even in the US, who would wear face masks without being forced to, assuming we could actually get our hands on them.

Hope so.

How prevalent was mask wearing in Asian cultures before SARS?

I read a paper on this last week but I can't find it at the moment. However I recall them polling people on mask usage, and pre-SARS it was single digits percentage, post-SARS it was 85-90%.

During the pandemic, yes. Not so much after. I live in S.E. Asia and have been to a large number of countries in Asia, and I can't say I've seen extensive mask usage anywhere except for Japan.

Of course, it's much more common than Europe or the US, but it's still in the single digit percentages.

This was before the current pandemic of course. But eve today, in Singapore, I'd estimate 15% to 20%?

Right now people wearing masks are considered selfish people who are depriving medical staff of them.

medical staff in usa are wearing trashbags for protection( even hilary clinton tweeted this picture).

Still not in Washington state. I'm routinely the only one wearing a simple surgical mask when I head to the grocery store, which I don't mind because people pro-actively avoid me because I guess they assume I'm infected instead of being precautious. Everyone should assume they are an asymptomatic carrier.

Even the most basic face masks would have some obvious consequences:

- preventing infected from spreading the virus via droplets

- preventing touching mouth and nose with your hands

For that to be effective, for a while anyone would need to wear a mask, as the virus is usually spread by people who don't feel sick yet. Wearing masks would add another barrier to spreading the virus, especially everywhere where you can't quite keep 2 meters of distance, e.g. shops, public transport and could be vital for reopening factories.

Depending on the mask, eg any N95 I’ve ever tried, you’ll touch your face a lot more to constantly readjust it because of skin irritation. Surgical masks are much more comfortable since they don’t form a seal.

I think, if we are talking about "masks for everyone" it can only be surgical masks, which are relatively cheap and comfortable. Or homemade replacements made from cloth, which can be washed and reused. Some German clothing companies already have started producing cloth masks too.

Yes, but the effectiveness goes way down. If we are talking about air pollution (why I had to wear them when I did), surgical masks are useless. I guess in the pandemic context, they prevent some moisture from your mouth from reaching other people.

It may be ideal to have the most at risk wear n95 masks (and ideally get them as much training on wearing them and only adjusting them with freshly cleaned hands) while the rest of the population wears surgical masks and makeshift masks of cloth or paper towels.

There were 560 cases the day they started the policy, and 2817 eleven days later. That's a "flattened" growth?

It will be interesting to see the Czech Republic's data and attempt to isolate the benefit of the policy, but I don't see how one could draw a conclusion at this point.

Detection is delayed. Many of those people may have got infected prior to the quarantine, or from family members during the quarantine.

But I agree, it’ll take more time to see how effective the measure is.

You should also keep in mind, that we've more than doubled the testing since, so the amount of cases raised with that as well.

flattened growth because the number of new cases is not growing very fast; it does not mean they have no new cases...

You can't see the effects of an intervention stopping new coronavirus infections until you wait past the end of the incubation period of the virus. And if you're not testing very aggressively it'll take another week beyond that for mild illnesses to turn into the sort of thing that gets people to the hospital.

Also, technically, if you go from an exponentially increasing problem to getting the same number of infections every day you've "flattened the growth" even though you haven't flattened the number cases.

Is the data available somewhere?

> Howard claimed that “one of the key reasons for the decrease in the growth of the cases is a massive country-wide community initiative to create and wear home-made masks.”

What are the other measures they took?

The data is available e.g. on the offical czech ministry of health https://onemocneni-aktualne.mzcr.cz/covid-19 (can be easily translated with google)

And here is the list of measures https://www.vlada.cz/en/media-centrum/aktualne/measures-adop...

Jeremy Howard's list of sources is here: https://tiny.cc/maskswork

Seems to me we all need to assume we're asymptotic carriers, and then follow WHO's (or CDC's) advice for sick people, which is to wear some sort of mask or bandana.

That isn’t WHO or CDC advice. If you are sick, you should just not go out.

https://www.cdc.gov/coronavirus/2019-ncov/if-you-are-sick/st...

CDC says if you "think you might have COVID-19", you should "wear a facemask" "to help protect other people in your home and community." "You may need to improvise a facemask using a scarf or bandana."

Seems to me we should assume we "might have COVID-19" and then follow CDC's advice to wear a scarf or bandana to protect other people.

Then those are different advices for thinking you might be sick and being actually sick. If you are sick, don’t go out. If you just think you might be sick, then put some cloth in front of your face.

No, the CDC says, on the linked page:

>If you are sick wear a facemask in the following situations, if available.

>- If you are sick: You should wear a facemask, if available, when you are around other people (including before you enter a healthcare provider’s office).

>- If you are caring for others: If the person who is sick is not able to wear a facemask (for example, because it causes trouble breathing), then as their caregiver, you should wear a facemask when in the same room with them. Visitors, other than caregivers, are not recommended.

>Note: During a public health emergency, facemasks may be reserved for healthcare workers. You may need to improvise a facemask using a scarf or bandana.

Yes, if you are sick, you should not go out and avoid other people as much as possible, but when you do have to go out to where other people inhabit, you should wear a mask, and the CDC says as much.

A lot of the transmission of this disease is between family members. With masks, this sort of transmission could be slowed or prevented.

I thought the World Health Organization said that masks don’t work. Why would they have said that if the opposite is true?

Seems like they would, based on their recent track record.

Not quite, but it's certainly been confusing advice, if you can call it advice at all: https://blogs.bmj.com/bmj/2020/03/11/whos-confusing-guidance...

It was mostly an effort to prevent panic buying like what happened with toilet paper. There are not enough masks produced even in a year to solve this, so they. Need to focus on medical workers having access.

You left out the word "lied"

There’s a big difference between a nuanced message and a lie. If you see The WHO statements as a lie, you lack the understanding of the situation needed to make a thoughtful decision, and it’s for the best that you were misled.

People who read the news and get “masks don’t work” out of it should not be using masks until there are enough available for professionals who need them.

If there are tons of studies showing that homemade masks prevent virus spread, almost no evidence to the contrary, and they tell people not to wear even homemade masks, I don't know what else to call it but "lying".

How about I meet you half way and call it an "incompetent noble lie".

https://docs.google.com/document/d/1HLrm0pqBN_5bdyysOeoOBX4p...

Can you please point to where WHO is saying people shouldn’t use homemade masks? I’ve never seen that claim, but if it’s true it indeed doesn’t make sense. I’ve only seen CDC dissuade people from using surgical and N95 masks.

Perhaps there’s concern that if CDC or others advise people to use homemade masks, people who actually do need N95 masks (e.g. severely immunocompromised) will think that works for them?

Edit: there’s also the moral hazard aspect to consider: if people think wearing homemade masks is enough to protect them, they’re probably a lot more likely to ignore quarantine or social distancing. If the masks aren’t 100% effective and are used wrong, that could be worse than just staying in and social distancing.

"You should only wear a mask if a healthcare professional recommends it."

A blanket statement against all types of masks without qualification.

https://www.cdc.gov/coronavirus/2019-ncov/faq.html

Right, the CDC FAQ seems to say don't wear masks.

However the CDC also says if you "think you might have COVID-19", you should "wear a facemask" "to help protect other people in your home and community." "You may need to improvise a facemask using a scarf or bandana."

https://www.cdc.gov/coronavirus/2019-ncov/if-you-are-sick/st...

Seems to me we should all assume we "might have COVID-19" and therefore follow CDC's advice: wear a facemask of some kind to protect other people.

BTW, that bit about the "bandana" was just added in the last week because people like me keep complaining about their guidance.

From hearing nurse aquaintances talk on Facebook, listening to This Week in Virology, etc it seems that the idea that surgical masks don't protect you from getting sick is very pervasive in the western medical community. And from a medical community standpoint it's true! If you're working with sick people every day and just use a surgical mask you'll probably get sick eventually. But in the game of telephone that is horizontal knowledge transfer "Surgical masks are generally insufficient for consistent protection in a medical setting" becomes "surgical masks don't work" and then becomes "a surgical mask won't protect you when you're going to buy groceries."

I didn’t think they said masks don’t work, but rather:

a. Masks mostly help people who are infected to not spread it widely (by catching their respiratory droplets, presumably).

b. There’s a global shortage and doctors and nurses really need them.

All I’ve been hearing locally is of course they help - hence the medical professionals need them - but that they don’t make as big of a difference if you’re a healthy person out in the world of mostly uninflected individuals, so please don’t buy any and let the doctors and nurses have them instead.

Because bureaucracies often accidently transform "not 100% guaranteed certainty" into "doesn't work"

I have been asking myself the same question. I think it comes down to two reasons:

1. Masks are in short supply and they believed they could save them for healthcare workers by convincing the general population they don't work.

2. If you are measuring efficacy, the general population won't reach the same level as a healthcare worker because they have not been professionally fitted and trained in on/off procedures. So instead of reducing risk by 95% the average person would see something like a 70% reduction, and they decided "perfect is better than good enough".

If they say "Masks work" when it only works 70% of the time then a lot of people will get sick despite wearing masks, there'll be a big public outcry, and people won't trust the WHO in the future.

As opposed to public outcry from them saying masks don't work while countries with mask usage fare better?

It would certainly be a failure if it is communicated that mask wearing prevents you from getting infected. They reduce the risk of infecting others more than they reduce the risk of getting infected.

A 20% reduction in infection risk is already substantial and worth it. If there is a 50% reduction in infecting others, mask use alone could replace most social distancing measures.

Maybe. Or they can just lose all trust instantly by claiming like the CDC, that they don't work. Now people who think will never trust the CDC ever again. Not sure what the WHO's wording was, but any organization not encouraging mass mask use cannot be trusted by anyone with a brain. Just because something isn't 100% effective, doesn't mean it's not effective. Only children and idiots think so. Unfortunately, we're surrounded by idiots.

Nobody said that they don't work. But they are not effective for the average person because a month ago there were so few confirmed cases in the US that it would be extremely unlikely that you would ever encounter a COVID positive person.

On the other hand, healthcare professionals have to deal with infected patients all day. Suppose a mask is 95% effective on a healthcare professional, and 90% effective on a normal person. But the healthcare professional is in close proximity to a coronavirus patient nearly all the time. Without a mask, there might be 20 chances of infection every day for them. A mask would prevent 19 chances of infection.

For a normal person, they might encounter one CoV positive person per day. That means that a mask prevents 0.9 chances of infection. This is much lower than 19.

This math is off because I didn't account for mask changings, etc. A healthcare worker should change their mask more frequently than a layperson. After accounting for mask changes, though, I'm sure that the healthcare workers still get more benefit.

There are two quite different usages:

1. Diminish the number of viruses that travel out of your mouth and land on the surroundings, there to be picked up by some passer-by.

2. Prevent viruses in your surroundings from reaching you.

AIUI the WHO and others have said quite loudly that masks don't work reliably for the second case.

> AIUI the WHO and others have said quite loudly that masks don't work reliably for the second case.

what does "not working reliably" mean?

People are stupid and use them wrong. I saw people while out shopping this week who absolutely did not handle their masks correctly; while the mask still probably helped them, I’d rather see that mask go to a medical professional who will use it correctly, especially in times of extreme shortage.

Not sure to keep the wearer from catching the disease. As opposed to merely improving the wearer's chances.

if you look up "does wearing a mask" on google, you'll find dozens of articles discussing the mixed messaging, how some countries encourage it while others discourage it, etc. so there's tons of back and forth with reasons/studies cited on both sides.

I've yet to see a definitive answer but essentially, one of the big arguments is that if you don't know that you have COVID-19 and since it's asymptomatic when you're already infectious, wearing a mask in public may help prevent the spread to others.

WHO doesn't only say things they are absolutely certain about - e.g. https://twitter.com/WHO/status/1217043229427761152

Also, not the most reliable source, but I've heard claims that initial viral load may determine the serverity - a mask could help here too: https://www.dailymail.co.uk/news/article-8166867/How-large-v...

The message from the community was to ensure mask supply for medical staff first. They are both more at risk themselves and a risk for others due to the large numbers of contacts.

Once supply is secured everyone should be educated about correct use and be encouraged to wear them.

Most of Asia already has a culture of wearing masks and existing supply chains. Europe/US did not and it takes a while to establish.

Other things WHO has said so far:

* Preliminary investigations conducted by the Chinese authorities have found no clear evidence of human-to-human transmission of the novel #coronavirus (2019-nCoV) identified in #Wuhan, #China

* WHO did not recommend any travel or trade restriction based on the current information available

No doubts about usefulness of masks, however its too early to call Czech Republic curve flat. Its anything but flat. Look at daily cases. There's not enough data points yet. Italian curve looks more promising. For last 11 days, there has been around 6,000 cases daily. Though, its likely from lack of testing.

Here's the official data: https://onemocneni-aktualne.mzcr.cz/covid-19

It shows various trends, numbers of tests, numbers of new positive people, etc.

Looks like the latest datapoints (fewer new cases) coincides with less testing. But it's hard to interpret. It may be the weekend (very nice weather), or it may be that less people are asking to get tested because there are fewer serious cases.

We'll see soon how it develops further.

This could be tried if there were enough masks. China prevented western N95 manufacturers from exporting masks out of their China facilities in February, so they will get first dibs on attempting this strategy. One of the unforeseen risks of globalization.

I think very basic face masks would be ok, as the idea is to limit people who are infected, from spreading the viruses so that other people get infected. The 2 m distance rule is about how far viruses are spread when speaking or coughing.

The article states that they're using homemade masks -- even t-shirts wrapped around their face.

It's not about filtering... there's something else happening here... I'd guess that the mask is a constant reminder to keep your hands off your face.

It's simple:

Spitting virus phlegm at people while coughing = BAD

Based on my own personal experience, I have to wonder if you're not on to something here. I wear just one glove every time I go to the supermarket and my nurse friends have been quick to point out to me that gloves are completely unnecessary. But I do not wear them because I think they'll protect me. I wear them precisely because they are a reminder not to touch my face. It's a simple reminder to myself that: "oh yeah, things are different now... be extra careful, don't touch your face, keep a safe distance from other people, etc." I'd be interested in knowing how many other people think like this. Having said all this, due to the shortages, I should probably stop wearing gloves and maybe just draw a large X on my hand or something to serve as this reminder.

The messaging here around the improvised masks was not about filtering (protecting yourself), it was about protecting the other people from bigger droplets. By proxy that also protects yourself somewhat if pretty much everyone is wearing something on their face.

This is of course only meaningful if almost everyone wears something. This is true at the moment.

Anyway, even improvised masks have some filtering capability. It just varies a lot based on many factors, and would not be something to depend on when you want predictability from PPE in a hospital. It's just that regular people should not have an excuse to spread their sputum everywhere just because they can't buy medical grade PPE.

>This is of course only meaningful if almost everyone wears something. This is true at the moment.

It's not true that you need almost everyone wearing something. Jeremy Howard wrote

>Studies have documented definitively that in controlled environments like airplanes, people with masks rarely infect others and rarely become infected themselves, while those without masks more easily infect others or become infected themselves.

>Masks don’t have to be complex to be effective. A 2013 paper tested a variety of household materials and found that something as simple as two layers of a cotton T-shirt is highly effective at blocking virus particles of a wide range of sizes. Oxford University found evidence this month for the effectiveness of simple fabric mouth and nose covers to be so compelling they now are officially acceptable for use in a hospital in many situations.

http://archive.vn/Dlabz#selection-1639.0-1653.170

Does that assume that infected people know who they are?

Sorry, I think I was confused by the "This" in your sentence that I quoted. I meant to point out that a mask protects you directly (if you are not sick) and not just by lowering the spread of the disease throughout the population. It seems that you actually agree and I misunderstood.

I think it is about filtering. Even simple cotton t-shirt cloth is about 50% effective at filtering 23nm microbes. Definitely not good enough to give to a healthcare worker in a high exposure environment, but also definitely good enough to flatten the curve when used at a population level.

https://www.researchgate.net/publication/258525804_Testing_t...

If you look at the pictures of people wearing masks in china, most are most definitely not wearing N95 masks, those are surgical masks. The only time I’ve seen everyone wearing an N95 are pictures coming out of hospitals.

N95s are technically called Particulate Respirators. What the Czechs are pushing for mass adoption are surgical masks or any type of mouth covering even scarves. Less effective, but sufficient to flatten the curve. And you can make them at home if you have sewing skills.

I can't recommend enough this video of Jeremy Howard (from Fast.ai fame): https://www.youtube.com/watch?v=BoDwXwZXsDI

There's a lot of scientific evidence that masks are useful.

Also some random arguments for masks are here:

https://aiki.info/masks/

The evidence is not clear yet, it will take ~ two weeks from implementation.

Graph -

https://en.wikipedia.org/wiki/2020_coronavirus_pandemic_in_t...

But you will also need lots of testing and contact tracing.

All these should decrease R0 and allow society to function.

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