[stupac2]

And, really, that makes sense. People keep talking about how transmissible this is, but it's still 1 case leading to at most 3.5 more. If it could linger for days on surfaces and anyone who touched that same surface was getting sick, that number would be a lot higher. Transmission is by far the most likely from sharing close quarters, where you're guaranteed to be breathing in the carrier's exhalations.

I'm sorry, but can you get it from simply breathing in air from a carrier? What I've read is that there needs to be droplets, i.e., coughing or sneezing, and that simply breathing the same air is insufficient. I know there is moisture in the air we exhale but would that carry the virus and is that sufficient enough to catch the infection? I don't know and now I need to know.

The video I posted on another thread (of a professor of infectious diseases in Korea) answers these questions. My read is that he said generally no, but the case of that church superspread was exceptional because people were singing and yelling in close quarters, in an enclosed space, for hours.

I've seen mixed things on that, but yeah, current best understanding is that it takes force of some kind. That's what I meant, this isn't something where you just walk by someone on the street and get it from them, it's from your partner or kid or coworker, or maybe the guy on bus/train. I have to think this is even more true now that people are starting to wear masks in public, I just wish I had some surgical masks, N95's seem like overkill and don't fit right with a beard anyway

[stupac2]

And, really, that makes sense. People keep talking about how transmissible this is, but it's still 1 case leading to at most 3.5 more. If it could linger for days on surfaces and anyone who touched that same surface was getting sick, that number would be a lot higher. Transmission is by far the most likely from sharing close quarters, where you're guaranteed to be breathing in the carrier's exhalations.

I'm sorry, but can you get it from simply breathing in air from a carrier? What I've read is that there needs to be droplets, i.e., coughing or sneezing, and that simply breathing the same air is insufficient. I know there is moisture in the air we exhale but would that carry the virus and is that sufficient enough to catch the infection? I don't know and now I need to know.

The video I posted on another thread (of a professor of infectious diseases in Korea) answers these questions. My read is that he said generally no, but the case of that church superspread was exceptional because people were singing and yelling in close quarters, in an enclosed space, for hours.

I've seen mixed things on that, but yeah, current best understanding is that it takes force of some kind. That's what I meant, this isn't something where you just walk by someone on the street and get it from them, it's from your partner or kid or coworker, or maybe the guy on bus/train. I have to think this is even more true now that people are starting to wear masks in public, I just wish I had some surgical masks, N95's seem like overkill and don't fit right with a beard anyway

[magnus]

I'm sorry, but can you get it from simply breathing in air from a carrier? What I've read is that there needs to be droplets, i.e., coughing or sneezing, and that simply breathing the same air is insufficient. I know there is moisture in the air we exhale but would that carry the virus and is that sufficient enough to catch the infection? I don't know and now I need to know.

Doctors are struggling with this question as we speak.  The guidelines from the CDC and thus the ones most hospitals use leverage the assumption that it's not aerosolized but I know that at least with ENT docs (And this may be selection bias...or some other bias if I picked the wrong bias. =)) they've noticed that a large number (excepting the frontline) of Dr deaths and infections were to ENT.  They theorized that ENTs are often doing airway procedures where they hover over the patient's face for up to an hour.  That's a lot of breathing -> only a surgical mask or even none at all -> higher viral load.

No studies that I've heard of to support the above though.  Just word of mouth.

[magnus]

I'm sorry, but can you get it from simply breathing in air from a carrier? What I've read is that there needs to be droplets, i.e., coughing or sneezing, and that simply breathing the same air is insufficient. I know there is moisture in the air we exhale but would that carry the virus and is that sufficient enough to catch the infection? I don't know and now I need to know.

Doctors are struggling with this question as we speak.  The guidelines from the CDC and thus the ones most hospitals use leverage the assumption that it's not aerosolized but I know that at least with ENT docs (And this may be selection bias...or some other bias if I picked the wrong bias. =)) they've noticed that a large number (excepting the frontline) of Dr deaths and infections were to ENT.  They theorized that ENTs are often doing airway procedures where they hover over the patient's face for up to an hour.  That's a lot of breathing -> only a surgical mask or even none at all -> higher viral load.

No studies that I've heard of to support the above though.  Just word of mouth.

[M T]

I reach into my freezer & take out a box of frozen beans that had been coughed on by someone that was sick 3 months earlier.

Then you're fine, the virus degrades after at most 72 hours.

You read this board, and I haven't made the effect of temperature clear enough?  Shame on me.

The recent correspondence that measured 3 days SURVIVAL was at room temperature (~72F), not at the Bay Area outside temperatures recently, at temperatures in the cargo hold of an airplane, and not at your refrigerator's or freezer's temperature.  Raise the temperature to 100 and the virus is inactivated quicker.  Keep it at a cooler temperature and it is active longer.

The recent report gave shorter survival times than other reports because it generally measured a drop of about 2 orders of magnitude for most of the surfaces, versus 3 orders of magnitude.  For instance, it reported a 3 day survival on plastic for SARS-CoV-1 while other reports measure up to 9 days.  Whether a drop of 2 orders of magnitude is enough presumably depends on the level of virus originally.  (Sort of a viral "Do you feel lucky, punk?" situation.)

Stop and think... What is special about freezing? Water freezes.  What has that to do with a virus?  Pretty much nothing.  If it is in a cell or in water, then maybe something.  But not if it is on a dry surface.  Coronaviruses have been shown to survive multiple rounds of dropping below freezing & warming up.

The virus is inactivated more quickly at higher temperature and higher humidity.  Conversely, it survives better at low temperature and low humidity.

This 2009 'Effects of Air Temperature and Relative Humidity on Coronavirus Survival on Surfaces" is a source of info for the 2020 survey article.  Check out Figure 1 and Figure 2.  At 4 degrees C and 20% humidity, the two coronaviruses (not SARS-CoV-2) have dropped by maybe a factor 3 (ie, not much) at 28 days.  At higher humidity, the coronaviruses dropped more significantly (3 orders of magnitude). 

As concerning to me is that the report showed only a 2 orders of magnitude of drop at room temperature at 28 days, 20% RH for the two coronaviruses.
(At 50% and 80% RH, they hit 3 orders of magnitude drop at about 5 to 14 days.)  Somehow they seemingly were protected from inactivation.


Of course, no one has shown that you can get COVID-19 from a box of frozen vegetables that was coughed on by someone with the disease.  This is working from measurements and extrapolating them.

[M T]

I reach into my freezer & take out a box of frozen beans that had been coughed on by someone that was sick 3 months earlier.

Then you're fine, the virus degrades after at most 72 hours.

You read this board, and I haven't made the effect of temperature clear enough?  Shame on me.

The recent correspondence that measured 3 days SURVIVAL was at room temperature (~72F), not at the Bay Area outside temperatures recently, at temperatures in the cargo hold of an airplane, and not at your refrigerator's or freezer's temperature.  Raise the temperature to 100 and the virus is inactivated quicker.  Keep it at a cooler temperature and it is active longer.

The recent report gave shorter survival times than other reports because it generally measured a drop of about 2 orders of magnitude for most of the surfaces, versus 3 orders of magnitude.  For instance, it reported a 3 day survival on plastic for SARS-CoV-1 while other reports measure up to 9 days.  Whether a drop of 2 orders of magnitude is enough presumably depends on the level of virus originally.  (Sort of a viral "Do you feel lucky, punk?" situation.)

Stop and think... What is special about freezing? Water freezes.  What has that to do with a virus?  Pretty much nothing.  If it is in a cell or in water, then maybe something.  But not if it is on a dry surface.  Coronaviruses have been shown to survive multiple rounds of dropping below freezing & warming up.

The virus is inactivated more quickly at higher temperature and higher humidity.  Conversely, it survives better at low temperature and low humidity.

This 2009 'Effects of Air Temperature and Relative Humidity on Coronavirus Survival on Surfaces" is a source of info for the 2020 survey article.  Check out Figure 1 and Figure 2.  At 4 degrees C and 20% humidity, the two coronaviruses (not SARS-CoV-2) have dropped by maybe a factor 3 (ie, not much) at 28 days.  At higher humidity, the coronaviruses dropped more significantly (3 orders of magnitude). 

As concerning to me is that the report showed only a 2 orders of magnitude of drop at room temperature at 28 days, 20% RH for the two coronaviruses.
(At 50% and 80% RH, they hit 3 orders of magnitude drop at about 5 to 14 days.)  Somehow they seemingly were protected from inactivation.


Of course, no one has shown that you can get COVID-19 from a box of frozen vegetables that was coughed on by someone with the disease.  This is working from measurements and extrapolating them.

[stupac2]

Extrapolating from other viruses onto this one is dangerous. The fact that with so many cases successfully traced without a single one going to surface transmission should tell you it's hard to do, and freezing something for years is not going to cause transmission, even if it might be one-in-a-billion possible. Just don't grab your frozen peas and immediately shove your finger into your nose and you'll be fine.

[stupac2]

Extrapolating from other viruses onto this one is dangerous. The fact that with so many cases successfully traced without a single one going to surface transmission should tell you it's hard to do, and freezing something for years is not going to cause transmission, even if it might be one-in-a-billion possible. Just don't grab your frozen peas and immediately shove your finger into your nose and you'll be fine.

[magnus]

Here's a roadmap proposed by a group headlined by Scott Gottlieb

https://www.aei.org/research-products/re...reopening/

Most of it has already been mentioned in this or other threads, including the need for more thorough testing and the need for everyone to wear masks.  

It suggests 4 phases. 
1 = Slow the spread
2 = state by state reopening
3 = establish immunity protection/ lift distancing
4 = rebuild for the future

[magnus]

Here's a roadmap proposed by a group headlined by Scott Gottlieb

https://www.aei.org/research-products/re...reopening/

Most of it has already been mentioned in this or other threads, including the need for more thorough testing and the need for everyone to wear masks.  

It suggests 4 phases. 
1 = Slow the spread
2 = state by state reopening
3 = establish immunity protection/ lift distancing
4 = rebuild for the future

[M T]

This suggests 72 hours max: https://hub.jhu.edu/2020/03/20/sars-cov-...-surfaces/

It's possible that lower temperatures slow it down, but probably not by a factor of 300. Also keep in mind that there's a large difference between "there's detectable virons at time t" and "you can get sick from the remaining virons at time t". The study suggesting 72 hours is actually the latter.

In fact, according to this exhaustively researched guide to covid food safety there haven't been any documented cases of transmission from surfaces. Is it possible? Sure. Is it likely? Not particularly.

And, really, that makes sense. People keep talking about how transmissible this is, but it's still 1 case leading to at most 3.5 more. If it could linger for days on surfaces and anyone who touched that same surface was getting sick, that number would be a lot higher. Transmission is by far the most likely from sharing close quarters, where you're guaranteed to be breathing in the carrier's exhalations.

Don't depend upon a derivative article.  Go back to the original research in the NEJM. 

Viruses were applied to copper, cardboard, stainless steel, and plastic maintained at 21 to 23°C and 40% relative humidity over 7 days.

Other research (which I referenced in another post here) indicates that at lower humidity, coronaviruses survive much longer, and that at lower temperature, coronaviruses survive much longer.

As for the "extensively researched guide" from SeriousEats, it writes

Temperatures and times for coronavirus are not yet fully researched, but scientists suggest a temperature of 149°F (65°C) for at least 3 minutes is sufficient.

but, if you follow the link in their guide, and read the research, you will see

At 65 °C, most of the virus was inactivated if incubated for longer than 4 min (Fig 2B). Again, some infectious virus could still be detected close to the limit of detection for the assay, after 20 min at 65 °C. While virus was incompletely inactivated at 56 and 65 °C even at 60 min, it was completely inactivated at 75 °C in 45 min (Fig 2[/url]C). Surprisingly, at both 56 and 65  °C the virus was inactivated at early time points but at 60 min a small amount of virus was detected.

I have to wonder where they got "3 minutes" from rather than 4 for those people who only want "most of the virus was inactivated", and why they didn't read the article they linked to when they say in that paragraph

Experts assume that the virus will respond like other pathogens and that hotter temperatures will require shorter times, but we currently do not have experimental data to prove it.

Another statement from SeriousEats that appears wrong is

According to multiple health and safety organizations worldwide, including [url=https://www.cdc.gov/coronavirus/2019-ncov/prepare/transmission.html]the CDC, the USDA, and the European Food safety Authority, there is currently no evidence that COVID-19 has spread through food or food packaging.

Follow that link to the CDC and you find

It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads.

(The statement that transfer by hand is not thought to be the main way, then why so much emphasis on washing hands and deprecate wearing a mask, and advising that a mask is only useful when accompanied by frequent hand washing?)

I see no asterisk on "surface or object" to say  "unless that surface or object is food or food packaging".  So, why would it be excluded?  Or, was SeriousEats simply saying that there is no evidence for what the CDC says?

[M T]

This suggests 72 hours max: https://hub.jhu.edu/2020/03/20/sars-cov-...-surfaces/

It's possible that lower temperatures slow it down, but probably not by a factor of 300. Also keep in mind that there's a large difference between "there's detectable virons at time t" and "you can get sick from the remaining virons at time t". The study suggesting 72 hours is actually the latter.

In fact, according to this exhaustively researched guide to covid food safety there haven't been any documented cases of transmission from surfaces. Is it possible? Sure. Is it likely? Not particularly.

And, really, that makes sense. People keep talking about how transmissible this is, but it's still 1 case leading to at most 3.5 more. If it could linger for days on surfaces and anyone who touched that same surface was getting sick, that number would be a lot higher. Transmission is by far the most likely from sharing close quarters, where you're guaranteed to be breathing in the carrier's exhalations.

Don't depend upon a derivative article.  Go back to the original research in the NEJM. 

Viruses were applied to copper, cardboard, stainless steel, and plastic maintained at 21 to 23°C and 40% relative humidity over 7 days.

Other research (which I referenced in another post here) indicates that at lower humidity, coronaviruses survive much longer, and that at lower temperature, coronaviruses survive much longer.

As for the "extensively researched guide" from SeriousEats, it writes

Temperatures and times for coronavirus are not yet fully researched, but scientists suggest a temperature of 149°F (65°C) for at least 3 minutes is sufficient.

but, if you follow the link in their guide, and read the research, you will see

At 65 °C, most of the virus was inactivated if incubated for longer than 4 min (Fig 2B). Again, some infectious virus could still be detected close to the limit of detection for the assay, after 20 min at 65 °C. While virus was incompletely inactivated at 56 and 65 °C even at 60 min, it was completely inactivated at 75 °C in 45 min (Fig 2[/url]C). Surprisingly, at both 56 and 65  °C the virus was inactivated at early time points but at 60 min a small amount of virus was detected.

I have to wonder where they got "3 minutes" from rather than 4 for those people who only want "most of the virus was inactivated", and why they didn't read the article they linked to when they say in that paragraph

Experts assume that the virus will respond like other pathogens and that hotter temperatures will require shorter times, but we currently do not have experimental data to prove it.

Another statement from SeriousEats that appears wrong is

According to multiple health and safety organizations worldwide, including [url=https://www.cdc.gov/coronavirus/2019-ncov/prepare/transmission.html]the CDC, the USDA, and the European Food safety Authority, there is currently no evidence that COVID-19 has spread through food or food packaging.

Follow that link to the CDC and you find

It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads.

(The statement that transfer by hand is not thought to be the main way, then why so much emphasis on washing hands and deprecate wearing a mask, and advising that a mask is only useful when accompanied by frequent hand washing?)

I see no asterisk on "surface or object" to say  "unless that surface or object is food or food packaging".  So, why would it be excluded?  Or, was SeriousEats simply saying that there is no evidence for what the CDC says?

[stupac2]

Why did you only follow the CDC link? The USDA one says:

Q: Can I become sick with coronavirus (COVID-19) from food?

A: We are not aware of any reports at this time of human illnesses that suggest COVID-19 can be transmitted by food or food packaging.

And the EFSA one says:

“Experiences from previous outbreaks of related coronaviruses, such as severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), show that transmission through food consumption did not occur,” noted EFSA’s chief scientist Marta Hugas.

“At the moment, there is no evidence to suggest that coronavirus is any different in this respect.”

If you want to do everything you can to minimize risk, then by all means be paranoid about surfaces. But there's no reason to think that surface contamination is a way that this spreads in any but the most contrived/unlikely scenarios.

[stupac2]

Why did you only follow the CDC link? The USDA one says:

Q: Can I become sick with coronavirus (COVID-19) from food?

A: We are not aware of any reports at this time of human illnesses that suggest COVID-19 can be transmitted by food or food packaging.

And the EFSA one says:

“Experiences from previous outbreaks of related coronaviruses, such as severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), show that transmission through food consumption did not occur,” noted EFSA’s chief scientist Marta Hugas.

“At the moment, there is no evidence to suggest that coronavirus is any different in this respect.”

If you want to do everything you can to minimize risk, then by all means be paranoid about surfaces. But there's no reason to think that surface contamination is a way that this spreads in any but the most contrived/unlikely scenarios.

[BostonCard]

(The statement that transfer by hand is not thought to be the main way, then why so much emphasis on washing hands and deprecate wearing a mask, and advising that a mask is only useful when accompanied by frequent hand washing?)

Because a well documented form of transmission does not involve a surface.  Sick patient touches face or coughs into hand -> shakes hand with healthy person -> healthy person rubs an itch in nose.  Washing hands interrupts the chain of transmission.

When most people wear a mask, they will touch the mask periodically to adjust it or touch their face because the mask gets uncomfortable with extended use.  Again, if your hand has picked up the virus, you have just inoculated yourself.

BC

[BostonCard]

(The statement that transfer by hand is not thought to be the main way, then why so much emphasis on washing hands and deprecate wearing a mask, and advising that a mask is only useful when accompanied by frequent hand washing?)

Because a well documented form of transmission does not involve a surface.  Sick patient touches face or coughs into hand -> shakes hand with healthy person -> healthy person rubs an itch in nose.  Washing hands interrupts the chain of transmission.

When most people wear a mask, they will touch the mask periodically to adjust it or touch their face because the mask gets uncomfortable with extended use.  Again, if your hand has picked up the virus, you have just inoculated yourself.

BC

[2006alum]

Returning to the subject of this thread, interesting new estimates from the Imperial College crew on SARS-COV-2 attack rates by country, and what this means for whether the R0 has fallen below 1. The good news is that R0 seems to fall below 1 pretty rapidly once social distancing measures are implemented:

[tweet]https://twitter.com/joshmich/status/1244645728619827200?s=20[/tweet]

And they take a crack at trying to estimate the lives saved as a result:
[tweet]https://twitter.com/joshmich/status/1244645735381032961?s=20[/tweet]

[2006alum]

Returning to the subject of this thread, interesting new estimates from the Imperial College crew on SARS-COV-2 attack rates by country, and what this means for whether the R0 has fallen below 1. The good news is that R0 seems to fall below 1 pretty rapidly once social distancing measures are implemented:

[tweet]https://twitter.com/joshmich/status/1244645728619827200?s=20[/tweet]

And they take a crack at trying to estimate the lives saved as a result:
[tweet]https://twitter.com/joshmich/status/1244645735381032961?s=20[/tweet]

[BostonCard]

I should add that for most people, the mask is probably most effective as a signaling device.  As Mick recounted in his anecdote, seeing someone with a mask is an immediate reminder that there is an pandemic going on and that a random person on the airplane you have just seen with a mask could be sick.  I'll bet dollars to donuts that the first class passenger, even though they accepted Mick's explanation that he was wearing the N95 as a precaution, nonetheless washed their hands right after the encounter, and probably took care to maintain social distancing with Mick and others.

BC

---

Returning to the subject of this thread, interesting new estimates from the Imperial College crew on SARS-COV-2 attack rates by country, and what this means for whether the R0 has fallen below 1. The good news is that R0 seems to fall below 1 pretty rapidly once social distancing measures are implemented:



[tweet]https://twitter.com/joshmich/status/1244645728619827200?s=20[/tweet]



And they take a crack at trying to estimate the lives saved as a result:

[tweet]https://twitter.com/joshmich/status/1244645735381032961?s=20[/tweet]

One thing that is striking is that their estimate of R0 (3 - 4) is higher than what has been published recently.  Also, the effect of the interventions short of lockdown are depressingly small.

BC

[BostonCard]

I should add that for most people, the mask is probably most effective as a signaling device.  As Mick recounted in his anecdote, seeing someone with a mask is an immediate reminder that there is an pandemic going on and that a random person on the airplane you have just seen with a mask could be sick.  I'll bet dollars to donuts that the first class passenger, even though they accepted Mick's explanation that he was wearing the N95 as a precaution, nonetheless washed their hands right after the encounter, and probably took care to maintain social distancing with Mick and others.

BC

---

Returning to the subject of this thread, interesting new estimates from the Imperial College crew on SARS-COV-2 attack rates by country, and what this means for whether the R0 has fallen below 1. The good news is that R0 seems to fall below 1 pretty rapidly once social distancing measures are implemented:



[tweet]https://twitter.com/joshmich/status/1244645728619827200?s=20[/tweet]



And they take a crack at trying to estimate the lives saved as a result:

[tweet]https://twitter.com/joshmich/status/1244645735381032961?s=20[/tweet]

One thing that is striking is that their estimate of R0 (3 - 4) is higher than what has been published recently.  Also, the effect of the interventions short of lockdown are depressingly small.

BC

[Mick]

I should add that for most people, the mask is probably most effective as a signaling device.  As Mick recounted in his anecdote, seeing someone with a mask is an immediate reminder that there is an pandemic going on and that a random person on the airplane you have just seen with a mask could be sick.  I'll bet dollars to donuts that the first class passenger, even though they accepted Mick's explanation that he was wearing the N95 as a precaution, nonetheless washed their hands right after the encounter, and probably took care to maintain social distancing with Mick and others.
BC

I didn't actually shake her hand, or touch her in any way.  And people socially distance themselves from me in any regard...  :D

[Mick]

I should add that for most people, the mask is probably most effective as a signaling device.  As Mick recounted in his anecdote, seeing someone with a mask is an immediate reminder that there is an pandemic going on and that a random person on the airplane you have just seen with a mask could be sick.  I'll bet dollars to donuts that the first class passenger, even though they accepted Mick's explanation that he was wearing the N95 as a precaution, nonetheless washed their hands right after the encounter, and probably took care to maintain social distancing with Mick and others.
BC

I didn't actually shake her hand, or touch her in any way.  And people socially distance themselves from me in any regard...  :D

[Snorlax94]

I should add that for most people, the mask is probably most effective as a signaling device.  As Mick recounted in his anecdote, seeing someone with a mask is an immediate reminder that there is an pandemic going on and that a random person on the airplane you have just seen with a mask could be sick.

This touches upon one of my big peeves, and even now, the WHO keeps saying masks should not be worn by all people, and in fact say people could harm themselves wearing a mask.

Countries in Asia like Taiwan, S Korea, Singapore and (SAR) Hong Kong use masks and they implore the world to use them.

If non-healthcare workers wear them incorrectly, then teach people. 

I absolutely agree that with a shortage of PPE, healthcare workers should be prioritized. Of course.

But I get so frustrated because now the goal is to build enough ppe for healthcare workers,  but our goal should be to build enough PPE for everyone, covering healthcare workers first.

Countries that have contained covid thus far (and have a lot more experience with SARS) recommend the general public wear masks. Maybe it’s social signalling, maybe it traps in spray from people who are asymptomatic, maybe it actually protects people. It doesn’t matter why, the US should be mobilizing far more resources to build massive amounts of ppe — first for healthcare workers, then for all Americans, then to share with the world.

[Snorlax94]

I should add that for most people, the mask is probably most effective as a signaling device.  As Mick recounted in his anecdote, seeing someone with a mask is an immediate reminder that there is an pandemic going on and that a random person on the airplane you have just seen with a mask could be sick.

This touches upon one of my big peeves, and even now, the WHO keeps saying masks should not be worn by all people, and in fact say people could harm themselves wearing a mask.

Countries in Asia like Taiwan, S Korea, Singapore and (SAR) Hong Kong use masks and they implore the world to use them.

If non-healthcare workers wear them incorrectly, then teach people. 

I absolutely agree that with a shortage of PPE, healthcare workers should be prioritized. Of course.

But I get so frustrated because now the goal is to build enough ppe for healthcare workers,  but our goal should be to build enough PPE for everyone, covering healthcare workers first.

Countries that have contained covid thus far (and have a lot more experience with SARS) recommend the general public wear masks. Maybe it’s social signalling, maybe it traps in spray from people who are asymptomatic, maybe it actually protects people. It doesn’t matter why, the US should be mobilizing far more resources to build massive amounts of ppe — first for healthcare workers, then for all Americans, then to share with the world.

[BostonCard]

Here’s the best summary of the evidence so far for masks and upper respiratory infections,  It’s somewhat equivocal, but the abstract says:

We included 67 studies including randomised controlled trials and observational studies with a mixed risk of bias. A total number of participants is not included as the total would be made up of a heterogenous set of observations (participant people, observations on participants and countries (object of some studies)). The risk of bias for five RCTs and most cluster‐RCTs was high. Observational studies were of mixed quality. Only case‐control data were sufficiently homogeneous to allow meta‐analysis. The highest quality cluster‐RCTs suggest respiratory virus spread can be prevented by hygienic measures, such as handwashing, especially around younger children. Benefit from reduced transmission from children to household members is broadly supported also in other study designs where the potential for confounding is greater.

Nine case‐control studies suggested implementing transmission barriers, isolation and hygienic measures are effective at containing respiratory virus epidemics. Surgical masks or N95 respirators were the most consistent and comprehensive supportive measures. N95 respirators were non‐inferior to simple surgical masks but more expensive, uncomfortable and irritating to skin. Adding virucidals or antiseptics to normal handwashing to decrease respiratory disease transmission remains uncertain. Global measures, such as screening at entry ports, led to a non‐significant marginal delay in spread. There was limited evidence that social distancing was effective, especially if related to the risk of exposure.

Note if you look at the table with the studies, it is less clear cut than the abstract makes it.

BC

[BostonCard]

Here’s the best summary of the evidence so far for masks and upper respiratory infections,  It’s somewhat equivocal, but the abstract says:

We included 67 studies including randomised controlled trials and observational studies with a mixed risk of bias. A total number of participants is not included as the total would be made up of a heterogenous set of observations (participant people, observations on participants and countries (object of some studies)). The risk of bias for five RCTs and most cluster‐RCTs was high. Observational studies were of mixed quality. Only case‐control data were sufficiently homogeneous to allow meta‐analysis. The highest quality cluster‐RCTs suggest respiratory virus spread can be prevented by hygienic measures, such as handwashing, especially around younger children. Benefit from reduced transmission from children to household members is broadly supported also in other study designs where the potential for confounding is greater.

Nine case‐control studies suggested implementing transmission barriers, isolation and hygienic measures are effective at containing respiratory virus epidemics. Surgical masks or N95 respirators were the most consistent and comprehensive supportive measures. N95 respirators were non‐inferior to simple surgical masks but more expensive, uncomfortable and irritating to skin. Adding virucidals or antiseptics to normal handwashing to decrease respiratory disease transmission remains uncertain. Global measures, such as screening at entry ports, led to a non‐significant marginal delay in spread. There was limited evidence that social distancing was effective, especially if related to the risk of exposure.

Note if you look at the table with the studies, it is less clear cut than the abstract makes it.

BC

[magnus]

More aerosol support. 

Choir in north WA had a 2.5 hour session in early March and 3/4 eventually were diagnosed or had symptoms.   No one recalls anyone showing symptoms at the time.   

https://nypost.com/2020/03/30/washington...s-kills-2/

Jamie Lloyd-Smith, an infectious disease researcher at UCLA, told the paper that members likely expelled viral particles into the air during the rehearsal.

“One could imagine that really trying to project your voice would also project more droplets and aerosols,” Smith said.

[magnus]

More aerosol support. 

Choir in north WA had a 2.5 hour session in early March and 3/4 eventually were diagnosed or had symptoms.   No one recalls anyone showing symptoms at the time.   

https://nypost.com/2020/03/30/washington...s-kills-2/

Jamie Lloyd-Smith, an infectious disease researcher at UCLA, told the paper that members likely expelled viral particles into the air during the rehearsal.

“One could imagine that really trying to project your voice would also project more droplets and aerosols,” Smith said.

[magnus]

Bad news.   One of our shining examples of how best to combat this virus just closed their schools for a month.   Singapore's grasp on their count is slipping away.  =(

That leaves Taiwan and South Korea (i don't count Japan.  Their count was artificially low due to limited testing) trying to hold firm against second waves. 

Not a good sign for whenever we might get the new case count down to a manageable number.

[magnus]

Bad news.   One of our shining examples of how best to combat this virus just closed their schools for a month.   Singapore's grasp on their count is slipping away.  =(

That leaves Taiwan and South Korea (i don't count Japan.  Their count was artificially low due to limited testing) trying to hold firm against second waves. 

Not a good sign for whenever we might get the new case count down to a manageable number.

[Goose]

Bad news.   One of our shining examples of how best to combat this virus just closed their schools for a month.   Singapore's grasp on their count is slipping away.  =(

That leaves Taiwan and South Korea (i don't count Japan.  Their count was artificially low due to limited testing) trying to hold firm against second waves. 

Not a good sign for whenever we might get the new case count down to a manageable number.

True, but Korea is hanging in there pretty well. At this point however, I see no real way any urban area in the USA can match Korea's efforts. AFAIK, we just aren't really trying to build up our capability. The Federal capability is very professional, very good(from what I am told), and very small. It can't cover the entire nation's needs and was never designed to do so. States and counties will have to step up, and I don't see them doing it.

[Goose]

Bad news.   One of our shining examples of how best to combat this virus just closed their schools for a month.   Singapore's grasp on their count is slipping away.  =(

That leaves Taiwan and South Korea (i don't count Japan.  Their count was artificially low due to limited testing) trying to hold firm against second waves. 

Not a good sign for whenever we might get the new case count down to a manageable number.

True, but Korea is hanging in there pretty well. At this point however, I see no real way any urban area in the USA can match Korea's efforts. AFAIK, we just aren't really trying to build up our capability. The Federal capability is very professional, very good(from what I am told), and very small. It can't cover the entire nation's needs and was never designed to do so. States and counties will have to step up, and I don't see them doing it.

[BostonCard]

There are 10 million newly unemployed people who could be trained pretty quickly to do the legwork for contact tracing and testing.

BC

[BostonCard]

There are 10 million newly unemployed people who could be trained pretty quickly to do the legwork for contact tracing and testing.

BC

[dabigv13]

Been saying for weeks this is what's gonna happen, at least in places that have the capability. The "Survivors" (feel like there is a better name, keep thinking of that episode of Curb, but I can't figure it) get a special pass.

https://www.nytimes.com/2020/04/04/world...e=Homepage

[dabigv13]

Been saying for weeks this is what's gonna happen, at least in places that have the capability. The "Survivors" (feel like there is a better name, keep thinking of that episode of Curb, but I can't figure it) get a special pass.

https://www.nytimes.com/2020/04/04/world...e=Homepage

[magnus]

In the Wapo article chronicling the white house's response to the novel coronavirus (that burger posted in another thread), the nugget i get out of that article...we have a (national?) tracking network for the flu.   Could that be expanded to track Covid-19?

[magnus]

In the Wapo article chronicling the white house's response to the novel coronavirus (that burger posted in another thread), the nugget i get out of that article...we have a (national?) tracking network for the flu.   Could that be expanded to track Covid-19?

[stupac2]

Been saying for weeks this is what's gonna happen, at least in places that have the capability. The "Survivors" (feel like there is a better name, keep thinking of that episode of Curb, but I can't figure it) get a special pass.

https://www.nytimes.com/2020/04/04/world...e=Homepage

My reaction is basically this paragraph:

That debate is in some ways ahead of the science. Researchers are uncertain, if hopeful, that antibodies in fact indicate immunity. But that has not stopped politicians from grasping at the idea as they come under increasing pressure to open economies and avoid inducing a widespread economic depression.

I guess it makes sense to plan ahead of time, but we don't know if antibodies actually grant immunity yet, and as someone pointed out via some twitter thread somewhere, even in relatively heavy-hit countries you need a damn good test to actually have confidence that the result is true (with incidence low enough you'll get more false positives than true positives even with >90% sensitivity).

[stupac2]

Been saying for weeks this is what's gonna happen, at least in places that have the capability. The "Survivors" (feel like there is a better name, keep thinking of that episode of Curb, but I can't figure it) get a special pass.

https://www.nytimes.com/2020/04/04/world...e=Homepage

My reaction is basically this paragraph:

That debate is in some ways ahead of the science. Researchers are uncertain, if hopeful, that antibodies in fact indicate immunity. But that has not stopped politicians from grasping at the idea as they come under increasing pressure to open economies and avoid inducing a widespread economic depression.

I guess it makes sense to plan ahead of time, but we don't know if antibodies actually grant immunity yet, and as someone pointed out via some twitter thread somewhere, even in relatively heavy-hit countries you need a damn good test to actually have confidence that the result is true (with incidence low enough you'll get more false positives than true positives even with >90% sensitivity).