> For a public health organization, the end doesn't justify the means.

Why not? This is a classic trolley problem and throwing the switch is absolutely the correct answer.

It's not classic trolley problem, because there are no second order effects modeled in the trolley problem. In this case, there is a secondary effect which is that the public realises they've been lied to and loses trust in public health authorities, which is exactly what has happened. You can only do that a couple of times before the authority has no authority.

This is different. A public health organization can only lie at large scale once before it loses the credibility that allows it to function in the first place.

... probably.

It is not even remotely a given that throwing the switch is the correct answer. The Czech Republic made masks mandatory, met that requirement by churning out a bunch of homemade masks, and have supposedly been quite successful in flattening their infection curve in doing so.

Going forward, misinformation gives every anti-vaxxer, skeptic, conspiracy theorist, and snake oil peddling bullshitter more ammunition with which to displace effective medical treatment going forward. Even the well meaning general populace becomes skeptical. You know what this results in?

Dead kids. Covid parties.

Trust in government is already so fucking slow people are throwing covid parties. And now you're suggesting that undermining that trust even more is the obvious answer?

For those of you casually tossing that around: https://www.lastwordonnothing.com/2020/03/25/the-trolley-and...

A load of people in this thread are saying the CDC (and others) are lying about masks.

For members of the public walking around a mask provides at best marginal benefit, and that's only if the wearer complies with a strict regime of donning and doffing protocols, and if it's combined with a full set of other PPE (disposable gowns, gloves, eye shields) and frequent handwashing.

As soon as you drop any of those you're not just making the mask a bit less effective, you're probably increasing the risk over not wearing a mask at all.

There are a few routes of transmission -

fecal oral; fomites to hand and then to eyes, nose, or mouth; and droplets landing on your eyes or being breathed in.

It's likely that in members of the public the main route is touching an infected surface and then touching your eyes, nose or mouth. Masks only help with breathing in droplets, and they only help if they're worn correctly. Incorrect mask wearing increases risk because masks feel weird and cause people to touch their face more often, and because masks give permission to people to go outside and mingle in crowds.

There's not much research around whether members of the public can wear PPE correctly, but there's plenty of research around PPE and healthcare professionals. We know that qualified registered healthcare professionals who know the consequences of not wearing PPE correctly still struggle to do it all correctly.

> Most people aren't idiots - if the masks help protect medical professionals from Covid-19, they can also help non-medical professionals.

The difference is that healthcare professionals spend all day in close contact with symptomatic people and are more likely to come into contact with blood or fecal matter or sputum, and are more likely to be doing aerosol-generating procedures, so the baseline risk is much higher, so that marginal benefit turns into an actual benefit. But importantly they're not just wearing masks. They're wearing gowns and gloves and eye protection and they have access to water and soap and alcohol hand gels and infection control teams to train them on how to wear it correctly.

Here's what HCPs are wearing. Are you honestly suggesting this for members of the public? https://twitter.com/QEGateshead/status/1244208756600307712

Here's a simple graphic for donning: https://twitter.com/agtruesdell/status/1245470479059767297?s...

Here's a thread talking about donning, wearing, and doffing PPE. https://twitter.com/halletjulie/status/1245409318775767042?s...

This is not the CDC / WHO / etc lying, this is them talking about the science as they understand it. https://twitter.com/shinybluedress/status/124277978004452147...

> even a bandana can likely help prevent disease transmission

You're basing this on a small study carried out in a lab using research bacteria (not viruses) carried in a calibrated spray, that didn't include "people breathing through the mask". You've massively overstated those results.

> You've massively overstated those results.

It's pretty fucking obvious that if you have Covid-19, and are expelling infected droplets into the air, almost any kind of mask will help reduce those droplets. I mean, wait for the double-blinded mask study (n=200) if you want. You may end up waiting for quite a while. Meanwhile, overall transmission rates in Asian mask-wearing countries are lower than Western transmission rates, despite taking many of the same precautions other than masks.

The point with masks, even rudimentary ones, is that they help prevent the wearer from transmitting respiratory disease.

And there's a point during a pandemic when you drop the Nature/Science level of evidence when you're talking about a relatively low-risk intervention like wearing a bandana.

In the words of the author of one the studies you disdain: "In normal times we'd say that if it wasn't shown statistically significant or the effective in real-world studies, we don't recommend it," he said. "But in the middle of a pandemic, we're desperate. The thinking is that even if it cuts down transmission a little bit, it's worth trying."

BTW, the author of the study I'm talking about here studied transmission of viral infections (influenza and coronaviruses) with an n of 111, not bacterial infections: https://www.nature.com/articles/s41591-020-0843-2 But there are multiple studies from the past decade that indicate that masks help prevent spread of respiratory viruses.

Finally, you harshly criticize my comment for lack of evidence, and yet you pull this one out: "It's likely that in members of the public the main route is touching an infected surface and then touching your eyes, nose or mouth." We have no idea if that's true or not at this point.

And here's another statement you pulled out of nowhere: "As soon as you drop any of those you're not just making the mask a bit less effective, you're probably increasing the risk over not wearing a mask at all."

You seem to have started from a position of defending the CDC, and then from there gone on cherry pick evidence or pull statements out of thin air.

There are people I know working at the CDC that I respect a great deal. But this PR campaign to lie to the American people to preserve mask stocks was a bad, bad idea.

> We know that qualified registered healthcare professionals who know the consequences of not wearing PPE correctly still struggle to do it all correctly.

No significant difference between fitted and non-fitted N-95 masks: https://www.ncbi.nlm.nih.gov/pubmed/21477136

And no, I wasn't even talking about wearing hospital-level PPE. I was talking about masks, and even mentioned bandanas, for crying out loud. But keep on spearing that red herring.

And here yet again, obviously N95 masks can help prevent transmission of respiratory viruses, including SARS-CoV-19. We know this to be true.

> This is not the CDC / WHO / etc lying, this is them talking about the science as they understand it.

You linked to some random ICU nurse, who makes some great points but has nothing to do with the CDC or WHO. But I agree that frontline health workers should absolutely have precedence to N-95 masks and other PPE.

> You're basing this on a small study carried out in a lab using research bacteria (not viruses) carried in a calibrated spray, that didn't include "people breathing through the mask".

Finally, you have no idea what I'm basing this on. Actually, it's common sense here that if you're infected, even as an asymptomatic carrier, wearing a bandana can reduce spread of droplets.