How the CDC’s restrictive testing guidelines hid the coronavirus epidemic • Hacker News Board

Re: How the CDC’s restrictive testing guidelines hid the coronavirus epidemic

#231

Post by mlthoughts2018 » Sun, Mar 22, 2020, 6:02 PM UTC

RotaryTelephone wrote: post #157

mlthoughts2018 wrote: post #76

Earlier quoted context omitted.

You did the right thing, don’t let anyone pressure you to feel otherwise. Retail stocks of masks for things like painting or carpentry are not at all related to depriving medical supplies. Also for N95 masks, the filter size is about 3x wider than the size of coronavirus. Meaning it provides _a lot_ of protection. It’s not a way to fully prevent anything, but a door only 3x wide lets in way way way fewer things than…

I think you mean 1/3rd as wide... 3x means a door that's three times bigger than a regular door. X means multiply.

I meant 3x. Coronavirus can go through N95 filter size, but just as mention in the link below, that’s still better than not using it. For certain situations, like needing to go out for errands and then be near the elderly, it’s smart to have it and makes sense for individuals to buy the retail stock.

https://www.wired.com/story/coronavirus-interview-larry-bril...

Re: How the CDC’s restrictive testing guidelines hid the coronavirus epidemic

#232

Post by kiba » Sun, Mar 22, 2020, 6:04 PM UTC

tomp wrote: post #215

SkyMarshal wrote: post #32

I hope one thing that comes of this outbreak is that all nations develop the processes and capabilities to quickly stop the spread of outbreaks in general. COVID19 is worse than flu, but not as bad as it could have been. We could get hit with something worse in the future. Imagine a strain of Ebola that gestates asymptomatically longer, or another coronavirus with higher mortality rate. This outbreak is good preparat…

> overreact early, quickly and briefly People were worried that overreacting (in particular if the outbreak fizzled out, in which case any reaction would have been an overreaction) would damage the economy. Personally, I viewed that as a positive - a decently resilient economy would absorb such short-term shocks without any long-term issues. Easiest way to force-create such an economy? Stress tests (c.f. Netflix’s Ch…

I am mostly worried about "crying wolves" too many time that people won't take it seriously.

Re: How the CDC’s restrictive testing guidelines hid the coronavirus epidemic

#233

Post by cycrutchfield » Sun, Mar 22, 2020, 6:06 PM UTC

gfodor wrote: post #187

jayd16 wrote: post #161

Earlier quoted context omitted.

This is a failure of the executive branch. Congress did its job long ago. The executive branch already had the legal means it needed but the administration chose to abdicate its responsibility.

Trump cancelled flights in January and was called xenophobic by the minority leader (who cowardly deleted the tweet.) There is plenty of blame to go around. If you actually want to prevent this from happening again, problems need to be corrected beyond the hypothesis of “we elected a bad leader.”

Cancelling flights is not even remotely courageous or impactful, given that the virus was already spreading in WA at that time. After January, the Trump administration did essentially nothing productive to prepare for the coming storm and squandered the following critical 6 weeks claiming it was no worse than the seasonal flu.

There is plenty of blame to go around but it concentrates at the top.

Re: How the CDC’s restrictive testing guidelines hid the coronavirus epidemic

#234

Post by bialpio » Sun, Mar 22, 2020, 6:08 PM UTC

Consultant32452 wrote: post #220

ardy42 wrote: post #207

Earlier quoted context omitted.

>> Surgical masks aren't about protecting the wearer from everyone else, they're about protecting everyone else from the wearer [1]. They may provide the wearer some protection, but that's not really the point. > I think you're confusing the normal use for these masks with what they are actually capable of doing. Yes, in a surgical setting the masks are worn primarily to protect the patient from the surgeon, but the…

Yes an N95 mask provides more protection than a surgical mask. That's completely different from whether either mask protects the wearer. Both masks absolutely protect the wearer from infection. I'm sure you understand that, but the way you are wording things makes this unclear.

If you have a mask shortage and there is one mask left in the country, is it better for the society for the sick person to wear it or for healthy person to wear it?

Re: How the CDC’s restrictive testing guidelines hid the coronavirus epidemic

#235

Post by NotSammyHagar » Sun, Mar 22, 2020, 6:09 PM UTC

SkyMarshal wrote: post #228

tomp wrote: post #215

Earlier quoted context omitted.

> overreact early, quickly and briefly People were worried that overreacting (in particular if the outbreak fizzled out, in which case any reaction would have been an overreaction) would damage the economy. Personally, I viewed that as a positive - a decently resilient economy would absorb such short-term shocks without any long-term issues. Easiest way to force-create such an economy? Stress tests (c.f. Netflix’s Ch…

Great idea, 100% agree. Let’s Chaos Monkey all the things, not just Netflix. > Personally, I viewed that as a positive - a decently resilient economy would absorb such short-term shocks without any long-term issues. That’s my sense of it too. The markets may fall in the short term, but as soon as the outbreak is stopped, roughly a month later, the markets will recover most or all of their losses. Politicians so afrai…

Yes, it's terrible that politicians in the us at least were doing their utmost to say this isn't a real problem because they didn't want to hurt the stock market and impact their re-election changes. But there's another side to testing things to failure in the real world, people can die. There are vulnerable people of every stripe. Unlike me they may barely get enough food, barely be able to pay that apt that depends on people going to a restaurant, barely have a way to get their medical care.

Most people aren't as fortunate as us computer programmers. I can get a job in a few days, even with the corona virus, not true of restaurant workers. And even some of us in the "programmer class" are struggling.

Some stress testing is good, but how to do it without killing the vulnerable.

Re: How the CDC’s restrictive testing guidelines hid the coronavirus epidemic

#236

Post by david_w » Sun, Mar 22, 2020, 6:12 PM UTC

tyingq wrote: post #5

The mask guidance is confusing as well. I get they are trying to preserve masks for medical staff. But, they also say it's mainly spread by coughing, sneezing, and resulting spray of bodily fluids. Surely even a scarf around your face would have some benefit? Yes, I get that the virus is small enough to pass through, but some deflection is better than none.

Viruses are very small: Virions, single virus particles, are very small, about 20–250 nanometers in diameter or 0.25 to 0.025 of a micrometer.

https://courses.lumenlearning.com/boundless-microbiology/cha...

The flu virus is typical: ...the flu virus is .17 microns in size.

https://www.envirosafetyproducts.com/resources/dust-masks-wh...

Masks work by trapping flu particles. The 95 in an N95 mask is shorthand for "this masks traps 95% of particles of size .3 microns.

There are also N99 and N100. N100 trap 99.7%. N100 when it is used in an air filter is called HEPA which I believe stands for High Efficiency Particle Attenuator or Arresting.

There is also a level above that found mostly in Europe called ULPA which pushes the decimal out further to 99.9997% . All of these aarea measure of the masks ability to trap particles of 0.3 except ULPA which is a measure of trapping particle 0.17

https://www.globalspec.com/learnmore/manufacturing_process_e...

Masks are matted fibers designed to trap particles on their fibers. They do this using 3 mechanisms which all masks share- diffusion, impaction and inertial impaction.

Diffusion happens when a particle is so small it is in Brownian (random) motion. These particles are trapped because they constantly change direction randomly as they pass through the mask and eventually run out of luck trying to dodge fibers. Such particles are less than 0.03 microns in size. (I should inject here that even though virus are smaller than this, there's more to the story as detailed below).

Inertial impaction happens when a particle is larger than .03 and owing to its size and momentum cannot change its direction of travel fast enough to stop itself running into a fiber.

Impaction happens when a particle comes within 1/2 of its radius of a fiber and touches it, becoming trapped. This is the most difficult size of particle to capture (as it happens) and that's why its the reference particle size for safety masks.

In the above I acted as though the particles were "trying" to avoid being trapped, but of course that's just a stub for the underlying physics off motion and magnetic attraction/repulsion which underlie these facts.

If you want to DIY some sort of mask to reduce your exposure, you have to consider that the weave of most cloth is far far wider than .03 and anyway not in layers (a cloth like yarn is the exception to the second property).

Just guessing but rags scarves etc lack the required fiber density to function as safety masks. It is possible that the virions would sail through them even under Brownian motion. But that is not really how virions are transmitted- they are transmitted mixed in with saliva particles which are hugely larger than the virions themselves. The size of a particle of saliva in a sneeze was examined here- tldr: a bimodal distribution of sneeze particle size all over 50 micrometers.

https://royalsocietypublishing.org/doi/full/10.1098/rsif.201...

Some other studies have put the size as small as .35 micrometer. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4676262/

What is really astonishing is how fast the particles travel- 200 MPH. https://www.livescience.com/3686-gross-science-cough-sneeze....

https://www.texairfilters.com/what-happens-to-the-particles-...

So all in all we can say this-any mask covering is better than no mask because it's an odds game with virus particles and saliva.

The less able you are to breath through it, the better it functions as a barrier.

Ordinary cloth is just not woven tightly enough to substitute for a p95 mask.

If you had to choose between multiple layers of x number of fibers and a tighter weave of the same fibers, it might be better to go for a tighter weave because even though individual virions would travel under Brownian motion, that's not how a spray of sneeze which is the transport mechanism of the virus is going to travel.

Some sneeze particles containing virions have a particle size of 5 microns and will stay aloft in a still room for a long, long, long time. If someone sneezes and three minutes later you walk through where they were, you could very well become the unknowing, unwilling next host of the virus.

That last - horrifying - fact is one of the the reasons why they're telling people to maintain social distancing and just stay home.

Re: How the CDC’s restrictive testing guidelines hid the coronavirus epidemic

#237

Post by gfodor » Sun, Mar 22, 2020, 6:16 PM UTC

cycrutchfield wrote: post #233

gfodor wrote: post #187

Earlier quoted context omitted.

Trump cancelled flights in January and was called xenophobic by the minority leader (who cowardly deleted the tweet.) There is plenty of blame to go around. If you actually want to prevent this from happening again, problems need to be corrected beyond the hypothesis of “we elected a bad leader.”

Cancelling flights is not even remotely courageous or impactful, given that the virus was already spreading in WA at that time. After January, the Trump administration did essentially nothing productive to prepare for the coming storm and squandered the following critical 6 weeks claiming it was no worse than the seasonal flu. There is plenty of blame to go around but it concentrates at the top.

The fact that you leap from "Trump should have done more" to "what Trump did was not impactful" shows your bias. Cancelling flights was impactful, but clearly insufficient. You're the one who is off-balance here, not me. There were systematic failures to recognize the threat from leaders and citizens alike. Regulatory structures that have been in place for decades have shown their cracks in an emergency. The CDC/FDA dumped tons of red tape on the testing process, and 'fixed' the problem by taking themselves out of the loop. The testing debacle was well underway during the timeline you mention - what does that tell you? If it only tells you "Trump fucked it up", you're not paying attention. It may be a contributing factor, but we have some real, serious problems beyond who is at the top of the executive branch. Similar weaknesses are about to be exposed in the clinical trial testing process, due to the degree to which we have culturally landed on p-values and statistical power needed to lead to action - there's a chance to correct that now, but if we're focused on Trump, and only Trump, we will fail to do so pre-emptively and it will cost more lives.

I have been preparing for this since early January, have you? If not, why not? If not, you fell into the trap almost everyone else did to fail to recognize the threat and the exponential nature of the threat. So stop throwing stones from within your glass house, and look forward. Critique the actions of leaders who are behind the curve today, not those who were behind it yesterday. The finger pointing backwards can happen later: for now, we should focus on course correction and survival.

Also, I did some more research, and it sounds like the tweet I was referencing above was in fact misinformation. So I stand corrected on that one! However, it was certainly the case that at the time flights were being called to be cancelled from China, there were accusations of xenophobia being through around.

Re: How the CDC’s restrictive testing guidelines hid the coronavirus epidemic

#238

Post by Consultant32452 » Sun, Mar 22, 2020, 6:25 PM UTC

bialpio wrote: post #234

Consultant32452 wrote: post #220

Earlier quoted context omitted.

Yes an N95 mask provides more protection than a surgical mask. That's completely different from whether either mask protects the wearer. Both masks absolutely protect the wearer from infection. I'm sure you understand that, but the way you are wording things makes this unclear.

If you have a mask shortage and there is one mask left in the country, is it better for the society for the sick person to wear it or for healthy person to wear it?

I simply will not stand to be "managed" or lied to. The masks protect the wearer. That is a simple fact. Anyone who states/implies otherwise is either ignorant or a liar.

Now we have the separate issue of the fact that there is a critical supply shortage. In such a scenario I'm more than happy to oblige in managing systemic risk by allocating all the masks to healthcare workers, the critically vulnerable, etc. But don't lie to me along the way.

Re: How the CDC’s restrictive testing guidelines hid the coronavirus epidemic

#239

Post by cycrutchfield » Sun, Mar 22, 2020, 6:26 PM UTC

gfodor wrote: post #237

cycrutchfield wrote: post #233

Earlier quoted context omitted.

Cancelling flights is not even remotely courageous or impactful, given that the virus was already spreading in WA at that time. After January, the Trump administration did essentially nothing productive to prepare for the coming storm and squandered the following critical 6 weeks claiming it was no worse than the seasonal flu. There is plenty of blame to go around but it concentrates at the top.

The fact that you leap from "Trump should have done more" to "what Trump did was not impactful" shows your bias. Cancelling flights was impactful, but clearly insufficient. You're the one who is off-balance here, not me. There were systematic failures to recognize the threat from leaders and citizens alike. Regulatory structures that have been in place for decades have shown their cracks in an emergency. The CDC/FDA…

As I said, there is plenty of blame to go around, but I am particularly incensed at a specific person who had the power to do more but essentially did nothing. In times of crisis, the quality of leadership matters tremendously. Trying to deflect by saying “the other side would have been the same” or “whatabout all these other people that failed” simply demonstrates the bias that you accuse me of.

Re: How the CDC’s restrictive testing guidelines hid the coronavirus epidemic

#240

Post by kps » Sun, Mar 22, 2020, 6:33 PM UTC

jtms wrote: post #98

I have a box of n95 masks I bought a few years back while living in Singapore (there is an annual smoke “haze” there from neighboring countries burning forest to clear land for palm oil production). I tried to give them to a nurse to distribute to other medical staff, but they couldn’t use them because they are a year or so beyond the expiration. News to me that masks even have an expiration date.

“CDC/NIOSH believes the following products, despite being past their manufacturer-designated shelf life, should provide the expected level of protection…

“3M 1860; 3M 1870; 3M 8210; 3M 9010; 3M 8000; Gerson 1730; Medline/Alpha Protech NON27501; Moldex 1512; Moldex 2201.”

https://www.cdc.gov/coronavirus/2019-ncov/release-stockpiled...