10 ms·
Respiratory virus shedding in exhaled breath and efficacy of face masks
- ceejayoz 7y agoAnother nail in the coffin for the "masks don't work" side of things.
- nisa 7y agonobody said masks don't work - the article doesn't contradict the fact that masks don't protect you very good against other infected people next to you. This article just repeats that it's known that masks help to prevent spreading of the disease if you have symptions and need to go outside. At least here in Germany nobody ever spoke out against that.
- vinniejames 7y agoWHO said masks don't work
- ejstronge 7y agoDo you have a link to this statement? I've primarily seen various authorities mention the primacy of hand washing, vs saying masks are ineffective.
- e12e 7y agoDon't know about gp, but here's what who seems to be saying now: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public/when-and-how-to-use-masks https://www.who.int/emergencies/diseases/novel-coronavirus-2...
- vinniejames 7y agoSurgeon General https://twitter.com/Surgeon_General/status/1233725785283932160 https://twitter.com/Surgeon_General/status/12337257852839321...
- AlexandrB 7y agoHere's what the WHO site[1] says: • If you are healthy, you only need to wear a mask if you are taking care of a person with suspected 2019-nCoV infection. • Wear a mask if you are coughing or sneezing. • Masks are effective only when used in combination with frequent hand-cleaning with alcohol-based hand rub or soap and water. • If you wear a mask, then you must know how to use it and dispose of it properly. Nowhere do I see: "Masks don't work". [1] https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public/when-and-how-to-use-masks https://www.who.int/emergencies/diseases/novel-coronavirus-2...
- dnissley 7y agoI think the first point is what most people are talking about when they're saying the WHO said "masks don't work". "Masks don't work" being short hand for "masks will only help you in these very narrowly defined circumstances."
- Mirioron 7y agoEven the third point is likely to discourage people from using masks. I find it difficult to believe that people with a mask, even if used poorly, see absolutely no benefit from the mask. The mask's presence on your face should already make you less likely to touch your face. Furthermore, the novel coronavirus is not the only thing to worry about. All of the other illnesses are still abound and will likely make you more susceptible to the novel coronavirus.
- vinniejames 7y agoExactly
- mancerayder 7y agoThe sense is that they're telling the general public not to use them, and the general public (and apparently, government figures) got that whiff. It's a folly that will be remembered and looked back negatively in history. One of many poor decisions by people in power.
- vinniejames 7y ago
- deleted 7y ago[deleted]
- ouid 7y agoIf you have the disease and don't have symptoms, you are still infectious, and this is why masks for everyone is one way to combat this virus.
- uxp100 7y agoUnfortunately the wayback machine didn't cache the CDC's page on guidelines until recently, but an article in US based Vox from February says: https://www.vox.com/recode/2020/2/13/21128209/coronavirus-fears-contagion-how-infection-spreads https://www.vox.com/recode/2020/2/13/21128209/coronavirus-fe... "Currently, the Centers for Disease Control and Prevention (CDC) advises against people in the US using face masks because most people who aren’t trained medical professionals may not know how to fit them properly, and the risk of exposure in the US is so low to begin with."
- captainmuon 7y agoMany people spoke out prominently against wearing masks in Germany, including Christian Drosten [1], der Spiegel [2] and Robert Koch Institute. [1] https://twitter.com/c_drosten/status/1241659738569539584 https://twitter.com/c_drosten/status/1241659738569539584 [2] https://www.spiegel.de/wissenschaft/medizin/corona-krise-die-kontroverse-um-atemschutzmasken-a-e8cfdfae-6509-4191-b600-0e63cff02f13 https://www.spiegel.de/wissenschaft/medizin/corona-krise-die... Yes, if you read between the lines the statements were often hedged, and not strictly speaking wrong: you should not wear masks (because healthcare workers need them more), masks dont protect (you) from coronavirus, there is no study that shows masks protect against the novel coronavirus (specifically). The general public just reads that you should not wear masks, period. Some people experienced hostility for wearing masks in public. You can get laughed at or coughed at. Asians wearing masks are avoided like they have the plague. And an old lady sneered at me (no mask) for keeping the required 2m safety distance in the supermarket, as if I was an idiot. That being said, most people are behaving exemplary and respecting physical distancing, and I hope the attitudes regarding masks will shift with time.
- david_w 7y agoMy old lady thanked me for crossing the street as she was proceeding south and me north. I pumped both fists in the air and exclaimed "we're not dead yet!" and she laughed. You live in a big city perhaps.
- ceejayoz 7y agohttps://twitter.com/surgeon_general/status/1233725785283932160 https://twitter.com/surgeon_general/status/12337257852839321... "Seriously people- STOP BUYING MASKS! They are NOT effective in preventing general public from catching #Coronavirus." The US Surgeon General, a little over a month ago.
- swader999 7y agoThey help prevent spreading when asymptomatic too. One of the key components to Taiwan's success.
- jplayer01 7y agoThen you must not have been talking to people. I’ve had to argue with way too many people since January who believe masks don’t work. I don’t know if people here are living in a pro-mask bubble or what, because there are too many people who believe they don’t work.
- oski 7y agoYesterday, the White House stated that they are about to issue revised guidelines around masks likely today or tomorrow. They are likely to advise people to wear cloth masks. At this point, I don't think anyone is really arguing that "masks don't work." Dr. Birx is worried that people will see masks as a substitute for other measures like social distancing, hand washing, and avoiding touching your face. There is a growing "grassroots" movement advocating that everyone wear homemade masks -- #masks4all Makes sense not to wait for the CDC on this on. Every day makes a huge difference. See https://shouldiwearafacemask.com https://shouldiwearafacemask.com for a summary.
- ceejayoz 7y ago> At this point, I don't think anyone is really arguing that "masks don't work." Yes, it's becoming an untenable position now. People were taking a very different tone a month ago with "we should all be wearing masks when out" suggestions. Hell, a week ago, HN was happily flagging pro-mask stuff off the front page with regularity.
- Izkata 7y ago> Dr. Birx is worried that people will see masks as a substitute for other measures like social distancing, hand washing, and avoiding touching your face. Just one point, but I have an interesting observation here: Earlier this week I finally found some masks, and last night wore one to the grocery store for the first time. It's about a 10-minute walk each way, and I encounter 5-6 dog-walkers in that distance. Usually the dog-walkers don't bother with social distancing, but while I was wearing the mask about half of them went out of their way to go around me.
- oski 7y agoYeah, they were probably worried that you were sick. But overall, it helps signal to everyone that you are taking precautions seriously. And the more people who wear masks, the less stigma there is associated with wearing them. The macro impact can be huge: "If 50% of the population were to wear masks, only 50% of the population would be infected by the virus. Once 80% of the population wears a mask, the outbreak can be stopped immediately." https://www.researchgate.net/publication/258525804_Testing_the_Efficacy_of_Homemade_Masks_Would_They_Protect_in_an_Influenza_Pandemic https://www.researchgate.net/publication/258525804_Testing_t...
- deleted 7y ago[deleted]
- chucklenorris 7y agosomething that i don't fully understand - as a healthy person does wearing a mask has any effect? or the masks work only for reducing the chance of transmitting the virus if already infected?
- dlandis 7y ago> something that i don't fully understand - as a healthy person does wearing a mask has any effect? Yes, of course it has an effect. Why do you think health care workers wear them?
- Angostura 7y ago"Yes, of course it has an effect. Why do you think health care workers wear them?" Because they will be closer than 6ft to infected people.
- ceejayoz 7y agoSo, if they work at less than six feet, they probably work at six feet or greater too, right?
- 0xffff2 7y agoSo am I every time I go grocery shopping. There are still a lot of people out shopping and not taking the distancing guidelines seriously. Enough so that when I went shopping earlier this week I found myself in multiple situations where it was impossible to maintain 6 feet.
- jartelt 7y agoWearing a mask helps block airborne droplets from the cough or sneeze of an infected person. That said, you need to aware that a mask is not perfect and you should still stay at least 6 feet away from other people. You also need to fit the mask properly and should avoid frequently adjusting the mask and touching your face with unwashed hands.
- oski 7y ago
- exhilaration 7y agoThis video was posted on /r/Coronavirus/ and was pretty interesting: Micro droplets suspending in air https://vimeo.com/402577241 https://vimeo.com/402577241
- ravenstine 7y agoThis is why people need to learn to listen to their intuition and their common sense instead of losing out to the tyranny of the experts during critical situations. I don't care if the experts don't want a run on masks. Anyone of modest intelligence knows that paper with little holes in it impedes the movement of air and droplets. Even if a mask is poorly sealed, surely it does something for both the infected and the uninfected, yet we've allowed the authorities, the experts, to gaslight us into accepting that the sky is blue so that they could augment their supply with masks intended to be sold to civilians. Under normal circumstances, individuals can afford to wait for evidence and listen to it. Now there are people who are going to die because they trusted the idea that they shouldn't wear a harmless piece of paper. If they didn't want a run on masks, they should have chosen to say something other than an insult to our intelligence, and then backtrack. And if you don't believe that the CDC, WHO, journalism outlets, were begging people to not wear masks back in February, I have to wonder what rock you've been living under.
- ceejayoz 7y agoThere are lots of places where common sense and intuition fail us. Experts are important. The issue here is they tried a hamfisted approach of lying to prevent panic buying. What should have happened was "masks work, here's an approved pattern you can make at home with just some cloth, and we're nationalizing PPE production and distribution for the time being; please know that's so the healthcare workers who may save your lives can stay alive".
- ravenstine 7y agoExactly. There's no denying that. And that's the public statement that we all deserved. But we're all too used to accepting misinformation from the authorities because we trust that they know better and that the ends will justify the means, which is a highly dangerous mindset because it damages our ability and willingness to distinguish reality of fantasy. In the worst case, it means that we'll accept anything.
- ceejayoz 7y ago
- calibas 7y agoWhy is virus transmission via aerosol such a controversial thing? When you cough, microscopic water drops get suspend in the air and studies have proven other strains of coronavirus can survive in these particles, especially in office conditions. https://www.ncbi.nlm.nih.gov/pubmed/32226116 https://www.ncbi.nlm.nih.gov/pubmed/32226116 And there's at least one study that found healthcare workers are at higher risk of infection during medical procedures that create aerosols. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3338532/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3338532/ Perhaps it's some human bias and we dread the idea that simply sharing the same atmosphere puts us at risk? This could be something very positive actually, and lead to rapid non-invasive testing. Imagine virus testing as part of the air filters on planes and cruise ships, could be a very powerful tool for preventing outbreaks.
- ceejayoz 7y agoIn the infectious disease world, droplets and aerosol aren't the same thing. https://www.statnews.com/2020/03/16/coronavirus-can-become-aerosol-doesnt-mean-doomed/ https://www.statnews.com/2020/03/16/coronavirus-can-become-a... > The reason the measles is so, well, viral, is that the microbe is so small and hardy that it is able to stay suspended in the air where an infected person coughed or sneezed for up to two hours, making it one of the only viruses that can exist as a true aerosol. > Now there are conflicting reports on whether the new coronavirus can. The studies suggesting that it can be aerosolized are only preliminary, and other research contradicts it, finding no aerosolized coronavirus particles in the hospital rooms of Covid-19 patients.
- calibas 7y agoYeah, different thing, and the studies I quoted are talking about aerosol transmission. I didn't mean to imply they're the same, simply that aerosol is microscopic "drops" of liquid.
- ceejayoz 7y agoWe know medical procedures like intubation can generate aerosols. My dad's hospital has, for example, set a 15 minute time-out in the trauma bay after one of these aerosol-generating procedures; your x-ray's gonna have to wait. We don't know that coughing alone generates significant amounts of coronavirus aerosols. The studies I've seen so far indicate it's not a major source of transmission; that droplets are the concern.
- beeforpork 7y agoOne thing in this study I find totally surprising is this: how can aerosol from different virus classes be differently contagious when passing through a mask? They seemed to have measured that, but it would really be very interesting to get an explanation how this is possible. How does a mask filter the contagion from corona aerosol, but not from rhino aerosol. This is totally perplexing to me.
- ceejayoz 7y agohttps://en.wikipedia.org/wiki/Rhinovirus https://en.wikipedia.org/wiki/Rhinovirus > They are lytic in nature and are among the smallest viruses, with diameters of about 30 nanometers. By comparison, other viruses, such as smallpox and vaccinia, are around ten times larger at about 300 nanometers; while flu viruses are around 80–120 nm. The smaller the virus, the easier it slips through a mask's fibers.
- chkaloon 7y agoJust to be clear, they are talking about surgical-type masks, similar to the cloth masks people are making. They are NOT talking about N95 "masks". There is constant confusion in the press and elsewhere between these two. One protects others (surgical mask), and one protects others AND the wearer (N95). Vox proposed that we call N95s by their technical term, "respirators", and other masks "masks", but then I suppose people will start confusing "respirators" and "ventilators"
- 0xffff2 7y agoI don't know that I entirely buy this. Okay, the masked I sewed myself out of an old shirt and some coffee filters isn't nearly as effective as an N95 mask, but is it really 0% effective? Surely it's better than nothing?
- chkaloon 7y agoBoy you're quite the contrarian. Congratulations. Did I say 0% effective? Talking about primary use here. You're right, though, that cloth or coffee filter is better than nothing.