Masks4All: Wear a mask to stop the spread of Coronavirus (Jeremy Howard) • Hacker News Board

Re: Masks4All: Wear a mask to stop the spread of Coronavirus (Jeremy Howard)

#151

Post by edanm » Tue, Mar 31, 2020, 7:03 PM UTC

phtrivier wrote: post #112

Please find a word that means "an ordinary piece of fabric that you can build yourself and wear if you're not sick". At least in France, "Wear a mask" would be understood as "wear an FFP2, surgical-level" mask. The kind of masks: * that we are in very short supply of at the moment (for various and sad reasons) * that we have to save for doctors * that everybody would try to buy on black markets if you asked them to u…

Very interesting linguistically.

My Argentinian wife tells me it's similar in Spanish - a mask would mean an N95 mask or similar. And a surgical mask would not be included if I understand correctly (they are not as good as N95 masks, they're mostly just a piece of fabric).

Re: Masks4All: Wear a mask to stop the spread of Coronavirus (Jeremy Howard)

#152

Post by gjlawran » Tue, Mar 31, 2020, 7:12 PM UTC

bmn__ wrote: post #113

dragontamer wrote: post #79

So, here's some information I've been seeing about masks. 1. After breathing in a mask for a while, the outside is now "potentially contaminated" with COVID19. Treat the outside of a mask as if it were infected. Do NOT touch the mask while using it. Do NOT rub your eyes, etc. etc. Do NOT put on the mask backwards. It is recommended to color-code the inside and outside to make it easier to see. 2. There are a ton of d…

Do not boil or steam respirator masks. It destroys the material and renders it less effective, sometimes drastically so. Instead disinfect them with dry heat in an oven or rice cooker. https://news.ycombinator.com/item?id=22680799

Here is an awesome technical video on using different methods to clean and reuse masks. Deals with Ozone, Alcohol, UV other disinfectants https://www.youtube.com/watch?v=2UdtKssU7po

Re: Masks4All: Wear a mask to stop the spread of Coronavirus (Jeremy Howard)

#153

Post by cameldrv » Tue, Mar 31, 2020, 8:25 PM UTC

dragontamer wrote: post #79

So, here's some information I've been seeing about masks. 1. After breathing in a mask for a while, the outside is now "potentially contaminated" with COVID19. Treat the outside of a mask as if it were infected. Do NOT touch the mask while using it. Do NOT rub your eyes, etc. etc. Do NOT put on the mask backwards. It is recommended to color-code the inside and outside to make it easier to see. 2. There are a ton of d…

If there is a good seal, N95 will do better than 95% in almost all cases. The 95% is for the maximum penetrating particle size, i.e. the worst case size particle. This is typically about 0.3um. Particles that are larger or smaller than this will be filtered above 95%. If you want to nerd out on filtration theory, https://en.wikipedia.org/wiki/HEPA is a good place to start.

Re: Masks4All: Wear a mask to stop the spread of Coronavirus (Jeremy Howard)

#154

Post by lecanucker » Tue, Mar 31, 2020, 8:35 PM UTC

anon102010 wrote: post #128

lecanucker wrote: post #100

Earlier quoted context omitted.

> hand to nose mouth contact is THE primary vector for this illness Do you have a source for this? It's contrary to most of what I've read (droplets through air is primary vector).

Droplets through the air is not primary vector - this is not aerosolized well like measels, the drops fall to the ground -> 6 foot rule is designed to avoid most droplets. "In an adjusted analysis of compliant subjects, masks as a group had protective efficacy in excess of 80% against clinical influenza-like illness." - https://www.ijidonline.com/article/S1201-9712(08)01008-4/ful... All the folks saying masks don't w…

I'm curious where you get the assertion that

> Droplets through the air is not primary vector

and

> hand to nose mouth contact is THE primary vector for this illness

In contrast, Johns Hopkins guide currently states: "Transmission - By respiratory droplets and by fomite. Virus found in respiratory secretions and saliva. - Viral shedding by asymptomatic people described, uncertain to what degree this occurs and abets transmission. - Stool shedding also described, but uncertain what role, if any, that plays." https://www.hopkinsguides.com/hopkins/view/Johns_Hopkins_ABX...

Re: Masks4All: Wear a mask to stop the spread of Coronavirus (Jeremy Howard)

#155

Post by anon102010 » Thu, Apr 02, 2020, 3:19 AM UTC

lecanucker wrote: post #154

anon102010 wrote: post #128

Earlier quoted context omitted.

Droplets through the air is not primary vector - this is not aerosolized well like measels, the drops fall to the ground -> 6 foot rule is designed to avoid most droplets. "In an adjusted analysis of compliant subjects, masks as a group had protective efficacy in excess of 80% against clinical influenza-like illness." - https://www.ijidonline.com/article/S1201-9712(08)01008-4/ful... All the folks saying masks don't w…

I'm curious where you get the assertion that > Droplets through the air is not primary vector and > hand to nose mouth contact is THE primary vector for this illness In contrast, Johns Hopkins guide currently states: "Transmission - By respiratory droplets and by fomite. Virus found in respiratory secretions and saliva. - Viral shedding by asymptomatic people described, uncertain to what degree this occurs and abets…

Droplets through the air (that land on the second parties nose or mouth) is not what Hopkins is talking about. The virus is in respiratory droplets. If you sneeze on something its contaminated. If you touch your nose or mouth and touch something its contaminated. etc. If someone touches any of those surfaces (hard to avoid in a shared space with door handles etc) they risk infection.

In daily living you touch door handles, gas pump handles, elevator buttons, railings, subway hang straps and bars etc. Even before covid, how many people sneezed on you? Far fewer.

If we just were worried about folks sneezing on us we could stop washing our hands.

Re: Masks4All: Wear a mask to stop the spread of Coronavirus (Jeremy Howard)

#156

Post by lecanucker » Fri, Apr 03, 2020, 3:10 PM UTC

anon102010 wrote: post #155

lecanucker wrote: post #154

Earlier quoted context omitted.

I'm curious where you get the assertion that > Droplets through the air is not primary vector and > hand to nose mouth contact is THE primary vector for this illness In contrast, Johns Hopkins guide currently states: "Transmission - By respiratory droplets and by fomite. Virus found in respiratory secretions and saliva. - Viral shedding by asymptomatic people described, uncertain to what degree this occurs and abets…

Droplets through the air (that land on the second parties nose or mouth) is not what Hopkins is talking about. The virus is in respiratory droplets. If you sneeze on something its contaminated. If you touch your nose or mouth and touch something its contaminated. etc. If someone touches any of those surfaces (hard to avoid in a shared space with door handles etc) they risk infection. In daily living you touch door ha…

I'm not trying to argue about whether hand washing is important. I'm trying to increase my understanding of the transmission, and I hadn't heard before that touch face/nose/mouth is the primary way of the disease spreading as you stated. As you had said earlier in the thread: "Please stop spreading misinformation as it could lead to deaths". If you have a source for stating it is the primary method of transmission, I'd still like to see it. Otherwise, perhaps don't repeat that claim, in the interest of not spreading misinformation.

Here's the best article I've found on transmission, and a key excerpt. http://www.cidrap.umn.edu/news-perspective/2020/03/commentar...

> In risk communication guidelines for healthcare, however, the WHO states, "COVID-19 appears to spread most easily through close contact with an infected person. When someone who has COVID-19 coughs or sneezes, small droplets are released and, if you are too close, you can breathe in the virus" (emphasis added).9 But wait: Inhalation is not part of the traditional definition of droplet transmission.

> For healthcare organizations, the CDC recommends airborne, in addition to standard (contact) and droplet precautions, for the care of COVID-19 suspected or confirmed patients.10

> For the general public, the CDC describes SARS-CoV-2 transmission as primarily by droplets from coughs or sneezes, which "land in the mouths or noses of people who are nearby or possibly inhaled into the lungs" (emphasis added).11 But, again, inhalation is a new addition to the traditional definition of droplets. In contrast to its recommendations for healthcare, the CDC makes no mention of airborne transmission in public settings.

> The CDC admits some possibility that COVID-19 may be transferred by hands to mouth, nose, or eyes from contaminated surfaces, but notes that "this is not thought to be the main way the virus spreads."11