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Face masks effectively limit the probability of SARS-CoV-2 transmission

science.sciencemag.org

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Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#361

Post by _Nat_ »

ComodoHacker wrote: post #333
_Nat_ wrote: post #130

Earlier quoted context omitted.

tl;dr - There wasn't really a conundrum to explain related to mask-effectiveness at different levels. Rather, it's more like a lack of good data, as prior studies being cited were ridiculously weak. --- This seems like a largely helpful characterization. However: > So they are left with a conundrum that places which use surgical masks seem to be better off, whereas randomized control studies of surgical masks show li…

The problem is people are not lab mice, you can't purposefully expose a test group to a virus to get clean data. So you either have to work with noisy data (as the previous studies you criticize) or turn to modelling (as this study does). This doesn't negate their value in either case. No need to be so picky.

In the absence of good data, the fallback is a position of ignorance -- not acceptance of bad data.

The prior studies were neither well-done nor directly relevant. As such, they didn't constitute good evidence on the topic of mask-wearing for the recent pandemic. The proper understanding would then be that the effectiveness of masks was little informed by such studies.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#362

Post by astrange »

greggman3 wrote: post #359
astrange wrote: post #299

Earlier quoted context omitted.

Japan is kind-of locked down, mostly by canceling large events and keeping people home. They're working on the principle that covid has mainly aerosol transmission and is spread by rare superspreaders rather than just everyone. It's working okay but not as well as Korea.

Japan isn't keeping people home. Restaurants are open (till 8pm). People are commuting in crowded trains, etc... I walk by the restaurants and cafes and they're plenty busy.

Did everyone give up on remote work?

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#363

Post by goatcode »

jMyles wrote: post #343
goatcode wrote: post #73

Earlier quoted context omitted.

>got a cold That's because the cold virus is spread by surfaces, and you likely touched something with it, then scratched your eyes. You can be 80 miles from someone, but if you touch something he touched, you're potentially getting his cold.

> That's because the cold virus is spread by surfaces Stop. There is no one virus called "the cold virus", and several of the viruses that do cause colds (including, for example, the other four endemic coronaviruses) are not known to spread by fomites.

You stop. Looks like we're both wrong: https://www.cdc.gov/features/rhinoviruses/index.html

It's either surface contact or ghosts coughing in the poster's face.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#364

Post by jMyles »

goatcode wrote: post #363
jMyles wrote: post #343

Earlier quoted context omitted.

> That's because the cold virus is spread by surfaces Stop. There is no one virus called "the cold virus", and several of the viruses that do cause colds (including, for example, the other four endemic coronaviruses) are not known to spread by fomites.

You stop. Looks like we're both wrong: https://www.cdc.gov/features/rhinoviruses/index.html It's either surface contact or ghosts coughing in the poster's face.

I didn't say that there aren't other viruses that cause colds that can be spread by fomites. I said that:

1) There isn't a single virus called "the cold virus"

2) In addition to SARS-CoV-2, there are other viruses that cause cold-like symptoms that are not spread by fomites.

Your comment gave the impression that there's a single "cold virus" for which fomite transmission is the primary vector. That's not so. There are a bunch of viruses (in fact a bunch of families of viruses) bunch that cause cold symptoms, and only a few of them are commonly spread by fomites. None of the five endemic coronaviruses are known to be among these, nor is influenza.

Also, even though the CDC appears to be correct to my eyes in this case, I urge that, after the disastrous departure from anything resembling science in the past year and a half, we stop regarding it as a credible source.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#365

Post by goatcode »

jMyles wrote: post #364
goatcode wrote: post #363

Earlier quoted context omitted.

You stop. Looks like we're both wrong: https://www.cdc.gov/features/rhinoviruses/index.html It's either surface contact or ghosts coughing in the poster's face.

I didn't say that there aren't other viruses that cause colds that can be spread by fomites. I said that: 1) There isn't a single virus called "the cold virus" 2) In addition to SARS-CoV-2, there are other viruses that cause cold-like symptoms that are not spread by fomites. Your comment gave the impression that there's a single "cold virus" for which fomite transmission is the primary vector. That's not so. There ar…

Stop again. Then read the link I posted.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#366

Post by asabjorn »

dragonwriter wrote: post #354
asabjorn wrote: post #349

Earlier quoted context omitted.

Death rate to confirmed cases is TX 1.7% (51k deaths over 2.9m cases), Florida 1.56% (36k deaths over 2296 cases), CA 1.64% (62k deaths over 3.74m cases) [source: google coronovirus stats]. So data does not confirm your conclusion.

Without stats on the age distribution of confirmed cases (even before considering the absence of analysis of confounding factors, liking case timing within the pandemic, etc.), I’m not sure how you can say the data doesn’t confirm the conclusion since you don’t have data on the proposed independent variable at all.

Yes, age distribution matters as older people are at higher risk. As some signal for this Florida is USAs old people home, so you would expect that if masks had a large positive mitigatory effect then Florida with its low mask use would do worse than CA and NY that has low mask use. However, we do not see this.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#367

Post by asabjorn »

chimprich wrote: post #355
asabjorn wrote: post #352

Earlier quoted context omitted.

People have traveled and moved extensively to Florida as well as TX from NY and CA, so any high-spread virus would spread to Florida and CA then spread within them. If masks and other strict lockdown measures were effective then by now open states such as Florida and NYC would see much higher death as well as covid case rates. See other comment I made in parent thread showing its about the same.

Strict lockdowns are effective. It's a virus that spreads through social contact. You restrict social contact, you reduce spread of the virus. It's not plausible to claim they're not effective. This feels like an argument from 12 months ago. They've demonstrably worked in Italy, the UK, New Zealand, China, and so on. They were the primary tool to constrain virus spread until vaccines came along.

What metric shows strict lockdowns are effective?

As I've shown outcomes on covid cases are equivalent in populous strict lockdown states (NY, CA) and open states (Florida, Texas). Death rate to confirmed covid cases is about 1.6% for all of these except NY that has 2.6%, controlling somewhat for differences in testing.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#368

Post by rdmirza »

I did not bother to read this thread in its entirety though I typically enjoy HN discussion.

Undoubtedly, masks of any quality work. Airborne viruses still exist in secretions (likely, in much higher concentrations). Secretions sometimes even carry living cells, would you imagine (in fact the #1 cause of sputum sample contamination for C&S; the bane of internists everywhere). High velocity events certainly increase the environment-load of secretion and thereby virus.

You don't need evidence in all cases. Im sorry to say, to the otherwise curious-minded, this is one of those cases.

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#369

Post by epivosism »

ppf wrote: post #264
epivosism wrote: post #59

Earlier quoted context omitted.

Yes. Crazy how hard it has been for people to get this: Imagine a bulletproof vest with three larger-than-bullet-sized holes in it. Say you know someone is going to shoot ten bullets at you - would you not wear the vest because "the attack vector can fit through the pores"? The point is people treat this as a binary 'safe' / 'not safe' switch, when actually risk is related to the distribution of exposure to dosage.

If we're talking about the size of the holes in a mask compared to a virus, then it would be more like wearing a "bulletproof" vest full of holes 10x bigger than a bullet.

But the area which does have coverage is still significant, right?

Re: Face masks effectively limit the probability of SARS-CoV-2 transmission

#370

Post by ddingus »

kelnos wrote: post #266
ddingus wrote: post #182

Earlier quoted context omitted.

There is a strong culture of individuality, and that is coupled with an extreme reluctance to just do what we're told, and what I mean by that is more about trust than Authority. Trust is low here, which is problematic for a scenario like this. Many of us did learn those lessons. For me personally when this all began, checking out what the world is doing seemed the natural thing to do. The US is also very insular, in…

I think it goes further than individuality, though. There's a pervasive selfishness that seems to run through our (American) culture. Many who do believe that COVID is a threat to others (say, to older people, or to immuno-compromised people) but do not believe that they themselves are in much danger will decide not to wear a mask because they don't think it matters to them if they do or not. This is the thing that m…

I agree strongly!

The idea of some effort, cost, minor sacrifice or inconvenience for a common, public good is not strong here.

Couple that being basically as insular on a personal level as we generally are nationally, and we find more of us than we may expect are empathy challenged too.

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