https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440799/
I'm using a homemade mask made from hepa filter material between two layers of dish towel material when I go out. I tie it around so it completely covers my nose and mouth and extents It will probably help if a person a few feet away coughs at me, as happened in the store today. And if I should cough, I may not infect someone else, if I am carrying.
And it may keep me from accidentally touching my face
Everyone on the ground having little ad hoc debates doesn't seem like it will converge onto a nationally organized solution. The fact that this is happening is symptomatic of the lack of leadership IMO, and so instead we're getting a disorganized cascade of businesses, institutions, mayors, and governors making ad hoc calls.
For me it was mind boggling when two days ago HN acted like the smart consensus was "masks do nothing, they are useless and don't wear it".
It is not just "little ad hoc debates". It is also clashing between cultures I guess. There are people down threads actively convincing others not to wear masks and implying you are uneducated if you do. Unless that side of discussion stops spreading it, people who got the "wear masks for others and yourself" advice should be allowed to state their case too.
I dont really know where "dont wear masks" meme is coming from, but it seems to be against everything I hear in my country. Person you are answering to might not be American either.
E.g. WHO: "a medical mask is not required, as no evidence is available on its usefulness to protect non-sick persons." https://www.who.int/publications-detail/advice-on-the-use-of...
NPR: "the scientific evidence that 'there might be a benefit for people in the community wearing [surgical] face masks is very, very meager.'" https://www.npr.org/sections/goatsandsoda/2020/01/29/8005317...
Then there's places saying the opposite: "Any type of general mask use is likely to decrease viral exposure and infection risk on a population level, in spite of imperfect fit and imperfect adherence" https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440799/
I don't know what to think, but I've ordered some (surgical) masks.
https://www.imperial.ac.uk/news/196234/covid19-imperial-rese...
Shows that the pandemic and associated social distancing measures may need to go on for months. How does the CDC switch messaging from saying that masks are useless to "well you should wear one now since you're going out..."
There are huge shortages of these masks in most US hospitals, even in areas with limited cases (cant speak for other coutnries but assume the same is true). HCPs are forced to either treat patients without wearing masks, guaranteeing high exposure to virus, or not care for patients
If you are sheltering in place (as you should be doing if you are healhty), N95 masks wont help you much. THey will 100% help HCPs
I was talking to a doctor yesterday, from Silver Spring, Maryland, right outside of DC. They ran out of N95 masks some time ago and can't find any more. They're using simple surgical masks now. Complaining won't make those N95 masks appear any faster.
What they're doing now is that each week there is one dedicated doctor who deals with Covid cases. This is to prevent the entire department from getting infected.
https://www.health.gov.au/resources/publications/coronavirus...
If you are well, you do not need to wear a surgical mask as there is little evidence supporting the widespread use of surgical masks in healthy people to prevent transmission in public.
They can say "little evidence" because only a few recent studies show that.
"A common claim is that surgical masks do not protect against respiratory viruses. This is not true. Several peer-reviewed studies in medical journals have found that correct and consistent use of surgical masks in household or community settings conferred a significant degree of protection against influenza, severe acute respiratory syndrome and other respiratory virus infections, especially when combined with hand hygiene."
and
"Another misconception is that surgical masks should only be worn by symptomatic individuals. In fact, surgical masks are effective when worn by both respiratory virus-infected persons and their contacts. Furthermore, it is well recognised that even asymptomatic Covid-19 patients can still be infectious to others, rendering this recommendation inapplicable to the current pandemic.
Like other respiratory viruses, Sars-CoV-2, the virus causing Covid-19, is largely transmitted by droplets from infected persons. Therefore, the scientific evidence in favour of mask use against other respiratory viruses is generalisable to Covid-19."
and
"have no hesitation in recommending universal mask usage for people living in neighbourhoods with community Covid-19 transmission"
By Dr Siddharth Sridhar, clinical assistant professor, Department of Microbiology, Li Ka Shing Faculty of Medicine, University of Hong Kong
https://www.scmp.com/comment/letters/article/3075103/coronav...
If you prefer, try this:
In this pragmatic, cluster randomized clinical trial involving 2862 health care personnel, there was no significant difference in the incidence of laboratory-confirmed influenza among health care personnel with the use of N95 respirators (8.2%) vs medical masks (7.2%).
"The coronavirus is an upper respiratory virus and a surgical mask does not protect you from that kind of virus,” he said. “In fact, when people buy up these masks and hoard these masks then they might not be available for healthcare providers to use for patient care.”
He said surgical masks are more effective on people who are already infected with an illness to keep them from infecting others rather than the other way around. He said other types of masks are not very effective at preventing you from getting sick either."
https://www.wibc.com/news/local-indiana/surgeon-general-surg...
>“Yes, a surgical mask can help prevent the flu,” Sherif Mossad, MD, an infectious disease specialist at the Cleveland Clinic, tells Health. “Flu is carried in air droplets, so a mask would mechanically prevent the flu virus from reaching other people.” It would work both ways, says Dr. Mossad, preventing transmission of the flu virus to others and for keeping a mask-wearer from picking up an infection.
Are you really going to change your surgical mask every 3 minutes to make it effective against getting infected?
How did you jumped from "reduced" to "completely useless".
> Are you really going to change your surgical mask every 3 minutes to make it effective against getting infected?
My typical situation is not surgical situation.
COVID-19 family is also pretty agile:
"The analysis of 22 studies reveals that human coronaviruses such as Severe Acute Respiratory Syndrome (SARS) coronavirus, Middle East Respiratory Syndrome (MERS) coronavirus or endemic human coronaviruses (HCoV) can persist on inanimate surfaces like metal, glass or plastic for up to 9 days."
https://www.sciencedirect.com/science/article/pii/S019567012...
Good luck relying on the safety from wearing surgical masks! /s
Aaaand you wear them also to not make sick others by spreading your virus as far as you breathe.
https://qph.fs.quoracdn.net/main-qimg-9bd2e88c4296be54e7f845...
https://www.nytimes.com/2020/03/17/opinion/coronavirus-face-...
If everybody in the US could wear one of these when out in public, we would be in a much better place. The sad truth is we don't have enough to do that, not that this would not help.
Surgical mask looks like this:
https://en.wikipedia.org/wiki/Surgical_mask
There is no respirator embedded as you can see, it's just a simple piece of fabric.
The point of my original reply was that we could reduce R0/transmission rate only if everybody had to wear surgical mask in public. If you are the only one wearing it, it doesn't really help. Some EU countries now require everybody to wear a mask while shopping or using public transport.
https://old.reddit.com/r/Prague/comments/fkdxvj/face_masks_n...
I thought it was a lower respiratory virus. I have no idea if that changes the efficacy of masks but...
Read just today that an advantage of any mask is it keeps people from transferring the virus from their fingers to their mouth and nose. A paper on the effectiveness of home made masks, like from tee shirt material says they are in no way a replacement for N95 masks but are better than nothing.
/Thats basically a misinformation. They are completely useless, and if you dont change them each 40-50 minutes - bring you more damage then good
https://blog.genealogybank.com/the-history-of-the-great-1918...
Evidence required.
If mist forms on my glasses from breathing, I assume the mask must be doing something.
I read a comment the other day on how many efforts are impeded by the "quest for perfection"
I know such homemade masks are not 100% proof. But even if they only work to reduce 10% of the risks if everybody wore them, than can be the difference between a R0 of 1.1 and 1.0 - and gives great results overall.
Don't just think about yourself. We are young and at no real risk of dying (0.1%, whatever). But we may cause the death of other people by simply contaminating more people.
Small actions are better than doing nothing when facing exponential growth
Same with masks, they are not perfect, they could be miss-handled, yet they provide some degree of safety and are better than nothing.... otherwise why would health officials wear them at all?
That just means the mask doesn't fit well, and air is going in and out the top instead of through.
There's a psychological component to this. If a mask reduces the chance of infection (from daily contact) from 60% (random number) to 54%, I'm not going to bother, even though in aggregate it might make a huge difference. That's just me though.
Also, I suspect half-measures like this are only effective in the early stages of the outbreak. For instance, if the viral load required for infection is 10 units (completely arbitrary), and your daily exposure is between 5 and 15, using a home-made mask that filters out 50% of viruses makes sense. However, if your daily exposure is 100 (presumably because everyone around you is infected), that 50% reduction isn't going to help you.
It breaks down when people are in isolation, which many of us now are. You are not out daily, so a 50% reduction is a 50% reduction, and with luck you never accumulate enough to get sick.
If everyone wore masks, then every ones daily exposure would drop dramatically. You get 50% less intake, and infected people are emitting much less too. You have pretty much eliminated air born transmission, and can now focus on hands and eyes.
This motherfucker created a brand new account to post scientific misinformation and YOU Dan are supporting that. What the FUCK is wrong with you Dan? How insane and hateful and malevolent towards humanity can you be?
BAN SCIENCE DAN. BAN IT. HARM PEOPLE, DESTROY MANKIND. THIS IS YOUR WAY.
Going into close contact with a person who has a known transmissible respiratory illness? N95 is minimum if you are a professional. And get your union to scream bloody murder if you are not allowed this essential safety equipment, and put complaints in writing so your heirs can later sue to oblivion.
Trying to massively reduce your risk when going out for supplies, or living with someone infected and have no other options? Surgical and homemade are vastly vastly vastly better than nothing.
Extremely antisocial, harmful, dangerous? Shaming those wearing masks.