Go Back  Bike Forums > The Lounge > Coronavirus/COVID-19
Reload this Page >

Maybe a breakthrough Coronavirus story

Notices
Coronavirus/COVID-19 Discussion of the novel coronavirus

Maybe a breakthrough Coronavirus story

Old 04-17-20, 06:02 PM
  #1  
Tony P.
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 243
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 171 Post(s)
Liked 113 Times in 63 Posts
Maybe a breakthrough Coronavirus story

I'm including here a story out of California that may signal a breakthrough in coronavirus thinking. The article suggests that roughly 50-80 times the number of people in Santa Clara County (an early epicenter) may actually have been infected compared to estimates. That is, 1,000 people were thought to be infected but the actual number may be 48,000 to 81,000.

The implications are obvious. Have a look if you're interested.

https://www.msn.com/en-us/news/us/co...ts/ar-BB12NSwD
Tony P. is offline  
Old 04-17-20, 06:17 PM
  #2  
wgscott
Occam's Rotor
 
wgscott's Avatar
 
Join Date: Jul 2013
Posts: 6,041
Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 2366 Post(s)
Liked 1,179 Times in 614 Posts
I'm not so sure the implications are obvious.

I got this in an email from a colleague a few hours ago:

A preprint of the serology study Stanford did March 3 & 4 was just posted:

https://www.medrxiv.org/content/10.1...463v1.full.pdf

Unfortunately, the study and analysis were very poorly done. They recruited individuals by a Facebook ad which is a biased subset of the population (white 30-50 year old wealthier people) and those that want to be tested (e.g. those that had COVID-19 symptoms).

They don't adjust the results for differences in age, profession, previous symptoms or socio-economic status b/w those sampled and the larger population. They don't even show their results by age at all.

Thus, while it's initially interesting (with estimated seroprev of 2.5%), I don't think it's interpretable at all. They had 50 seropositive individuals total, out of 3439. Even modest biases due to any of the factors I've listed above would change the results substantially. They also had very different sensitivity than the manufacturers specs but again don't present results in a way to fully understand them.

The other thing I would worry about is cross-reactivity with other coronaviruses (there are several human coronaviruses that cause cold symptoms and are essentially harmless, so good controls for this are essential.)
wgscott is offline  
Likes For wgscott:
Old 04-18-20, 04:41 AM
  #3  
Tony P.
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 243
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 171 Post(s)
Liked 113 Times in 63 Posts
Originally Posted by wgscott View Post
I'm not so sure the implications are obvious.
While the study focused on in the article has issues, the article says LA public health and USC also launched a study which (although unfinished) appears to show similar results.

The current death rate in Santa Clara County is approx. 4%, not very far off from the US death rate. Even if this study is double the actual infections, the death rate goes down to roughly .2%. Beyond that, US infections could be 20 million rather than 712K confirmed infections.

I'm not saying any of those (or any) numbers are correct but they point out two implications I think are obvious:
  • The study demonstrates that the number of undocumented infections is multiple times those confirmed.
  • Testing has been woefully inadequate.
While both implications have been widely assumed, this is the first attempt at verification.
Tony P. is offline  
Old 04-18-20, 05:26 AM
  #4  
50PlusCycling
Senior Member
 
50PlusCycling's Avatar
 
Join Date: Mar 2018
Posts: 302
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 132 Post(s)
Likes: 0
Liked 37 Times in 23 Posts
COVID 19 infection rate may be 75 times higher than diagnosed cases

An interesting study out of Stanford university trying to determine the scale of the COVID 19 outbreak. It has been quite obvious the the number of actual cases must be many times the number of confirmed cases given that 50 or more percent of those infected show no symptoms. However, Stanford's preliminary studies indicate the virus is far-and-away more widespread than we thought. Although I doubt COVID 19 is as widespread as the study seems to show, it must still be far more than the number of confirmed cases indicate.

Seroprevalence in Santa Clara County

https://www.medrxiv.org/content/10.1....14.20062463v1
50PlusCycling is offline  
Old 04-18-20, 07:47 AM
  #5  
rumrunn6
Senior Member
 
rumrunn6's Avatar
 
Join Date: Jul 2008
Location: 25 miles northwest of Boston
Posts: 24,865

Bikes: Bottecchia Sprint, GT Timberline 29r

Mentioned: 103 Post(s)
Tagged: 0 Thread(s)
Quoted: 3719 Post(s)
Liked 837 Times in 583 Posts
that may be true but itís also true that the less exposure you have, means the less severe a reaction you get & conversely, loading up on virus due to increased exposure means a more severe reaction is likely. I might have a mild undiagnosed case, but Iím not risking making it worse by going back to my side job at the home improvement store. I go thru an extensive decontamination process after post office & 20 minutes in a grocery store. Not about to spend 8 hrs in an enclosed publicly accessed space

Last edited by rumrunn6; 04-18-20 at 07:57 AM.
rumrunn6 is offline  
Old 04-18-20, 08:40 AM
  #6  
Tony P.
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 243
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 171 Post(s)
Liked 113 Times in 63 Posts
Originally Posted by rumrunn6 View Post
that may be true but itís also true that the less exposure you have, means the less severe a reaction you get & conversely, loading up on virus due to increased exposure means a more severe reaction is likely. I might have a mild undiagnosed case, but Iím not risking making it worse by going back to my side job at the home improvement store. I go thru an extensive decontamination process after post office & 20 minutes in a grocery store. Not about to spend 8 hrs in an enclosed publicly accessed space
I'd say you may be correct but I doubt it. Is there anything to support your statement or is it just a theory? Clearly there's a correlation between age / race / certain preexisting conditions and health risk but I've seen nothing to suggest length of exposure relates to the degree of infection. It seems to me that if touching a handle could lead to severe exposure, it doesn't take much.
Tony P. is offline  
Old 04-18-20, 09:33 AM
  #7  
wgscott
Occam's Rotor
 
wgscott's Avatar
 
Join Date: Jul 2013
Posts: 6,041
Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 2366 Post(s)
Liked 1,179 Times in 614 Posts
They had 50 seropositive individuals total, out of 3439.

There is a lot of extrapolation going on with this, so caution in interpretation is not unreasonable.
  • Is the test-set biased?
  • Is there a control-set? (I can't see one from reading their pre-print.)
  • Does the test give false-positives based on exposure to other (harmless) human coronaviruses that circulate through the population?
This is where rigorous peer-review becomes important. As it stands, this pre-print and press release is now national news, and the folks with confederate flags and automatic weapons who are protesting the state lockdowns are already claiming this demonstrates widespread heard immunity and vindicates the claim that the virus is no more dangerous than the flu (neither of which are justifiable, even if the study is completely flawless).
wgscott is offline  
Old 04-18-20, 09:36 AM
  #8  
rumrunn6
Senior Member
 
rumrunn6's Avatar
 
Join Date: Jul 2008
Location: 25 miles northwest of Boston
Posts: 24,865

Bikes: Bottecchia Sprint, GT Timberline 29r

Mentioned: 103 Post(s)
Tagged: 0 Thread(s)
Quoted: 3719 Post(s)
Liked 837 Times in 583 Posts
Originally Posted by Tony P. View Post
I'd say you may be correct but I doubt it. Is there anything to support your statement
yes of course there is but Iím in my phone now
rumrunn6 is offline  
Old 04-18-20, 09:39 AM
  #9  
livedarklions
Cyclesomatic
 
livedarklions's Avatar
 
Join Date: Jun 2018
Location: New England
Posts: 7,204

Bikes: Serotta Atlanta; 1994 Specialized Allez Pro; Motobecane Fantom CX; Giant OCR A1

Mentioned: 45 Post(s)
Tagged: 0 Thread(s)
Quoted: 3731 Post(s)
Liked 2,513 Times in 1,441 Posts
Originally Posted by Tony P. View Post
I'd say you may be correct but I doubt it. Is there anything to support your statement or is it just a theory? Clearly there's a correlation between age / race / certain preexisting conditions and health risk but I've seen nothing to suggest length of exposure relates to the degree of infection. It seems to me that if touching a handle could lead to severe exposure, it doesn't take much.
It's really a question of whether the size of the viral dose correlates with the severity of the infection. It's still too early to know. Given that there doesn't seem to be a correlation between viral load and severity of disease (that's still being studied), it's certainly not clear that does matters.
https://www.businessinsider.com/impo...ose-leave-us-6

One thing is pretty obvious, though, the more virus in your immediate environment, the more likely it is that you will contract it.
livedarklions is offline  
Old 04-18-20, 09:41 AM
  #10  
noisebeam
Arizona Dessert
 
noisebeam's Avatar
 
Join Date: Jun 2004
Location: AZ
Posts: 14,789

Bikes: Cannondale SuperSix, Lemond Poprad. Retired: Jamis Sputnik, Centurion LeMans Fixed, Diamond Back ascent ex

Mentioned: 59 Post(s)
Tagged: 0 Thread(s)
Quoted: 4131 Post(s)
Liked 760 Times in 418 Posts
Originally Posted by Tony P. View Post
I'd say you may be correct but I doubt it. Is there anything to support your statement or is it just a theory? Clearly there's a correlation between age / race / certain preexisting conditions and health risk but I've seen nothing to suggest length of exposure relates to the degree of infection. It seems to me that if touching a handle could lead to severe exposure, it doesn't take much.
See this opinion piece in NYT:
https://www.nytimes.com/2020/04/01/o...iral-dose.html
Both small and large amounts of virus can replicate within our cells and cause severe disease in vulnerable individuals such as the immunocompromised. In healthy people, however, immune systems respond as soon as they sense a virus growing inside. Recovery depends on which wins the race: viral spread or immune activation.

Virus experts know that viral dose affects illness severity. In the lab, mice receiving a low dose of virus clear it and recover, while the same virus at a higher dose kills them. Dose sensitivity has been observed for every common acute viral infection that has been studied in lab animals, including coronaviruses.
What is unknown is the data based specifics of dose quantity and repetition in regard to CV19 infection severity.
noisebeam is offline  
Likes For noisebeam:
Old 04-18-20, 09:43 AM
  #11  
wgscott
Occam's Rotor
 
wgscott's Avatar
 
Join Date: Jul 2013
Posts: 6,041
Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 2366 Post(s)
Liked 1,179 Times in 614 Posts
Originally Posted by rumrunn6 View Post
yes of course there is but Iím in my phone now
I knew that phones were getting really big, but that is quite remarkable. Is it comfortable?

BTW, those reports are anecdotal. It isn't a crazy assumption, but it isn't established fact. You only need one virus particle to give you an infection. Once it gets going, it can be as severe as any. It might just take a few more days to get to the organ-failure stage.
wgscott is offline  
Old 04-18-20, 09:44 AM
  #12  
wgscott
Occam's Rotor
 
wgscott's Avatar
 
Join Date: Jul 2013
Posts: 6,041
Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 2366 Post(s)
Liked 1,179 Times in 614 Posts
Originally Posted by noisebeam View Post
See this opinion piece in NYT:
It may be correct, but there is a reason why the NYT labeled it an opinion.

It isn't a toxin. It is a replicating virion. You only need one.
wgscott is offline  
Old 04-18-20, 09:46 AM
  #13  
noisebeam
Arizona Dessert
 
noisebeam's Avatar
 
Join Date: Jun 2004
Location: AZ
Posts: 14,789

Bikes: Cannondale SuperSix, Lemond Poprad. Retired: Jamis Sputnik, Centurion LeMans Fixed, Diamond Back ascent ex

Mentioned: 59 Post(s)
Tagged: 0 Thread(s)
Quoted: 4131 Post(s)
Liked 760 Times in 418 Posts
That is why I intentionally called it out as opinion to give a heads up.
noisebeam is offline  
Old 04-18-20, 09:55 AM
  #14  
noisebeam
Arizona Dessert
 
noisebeam's Avatar
 
Join Date: Jun 2004
Location: AZ
Posts: 14,789

Bikes: Cannondale SuperSix, Lemond Poprad. Retired: Jamis Sputnik, Centurion LeMans Fixed, Diamond Back ascent ex

Mentioned: 59 Post(s)
Tagged: 0 Thread(s)
Quoted: 4131 Post(s)
Liked 760 Times in 418 Posts
Originally Posted by wgscott View Post
It isn't a toxin. It is a replicating virion. You only need one.
True, but it is a replicating viron in an environment with attackers. Start with a small load and the attackers may be more successful (and can do so without overloading the body.) That pattern has been seen with many other viruses including coronas.
noisebeam is offline  
Old 04-18-20, 10:13 AM
  #15  
wgscott
Occam's Rotor
 
wgscott's Avatar
 
Join Date: Jul 2013
Posts: 6,041
Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 2366 Post(s)
Liked 1,179 Times in 614 Posts
Originally Posted by noisebeam View Post
True, but it is a replicating viron in an environment with attackers. Start with a small load and the attackers may be more successful (and can do so without overloading the body.) That pattern has been seen with many other viruses including coronas.
The more individual events, the greater the probability of infection. The "overload" part of the explanation is where it gets trickier. The severe complications result from the immune response later in the infection, so correlation with the severity of the infection, vs. probability of transmitting the infection, is the difficult part. (I think the NYT opinion piece (which I have also posted here, previously) is very likely to be correct, by the way. But that isn't based upon much more than my own expectation bias.) One of the problems is it doesn't give much of an explanation for why someone can so easily acquire the disease from a low or asymptomatic individual and then go on to develop full-blown, sometimes lethal, complications. It does give a good explanation for why medical workers are at 10X greater risk of infection, and why those tend to be severe. So I think it is at least part of the story, but there is more to it.

Last edited by wgscott; 04-18-20 at 10:25 AM.
wgscott is offline  
Old 04-18-20, 10:27 AM
  #16  
noisebeam
Arizona Dessert
 
noisebeam's Avatar
 
Join Date: Jun 2004
Location: AZ
Posts: 14,789

Bikes: Cannondale SuperSix, Lemond Poprad. Retired: Jamis Sputnik, Centurion LeMans Fixed, Diamond Back ascent ex

Mentioned: 59 Post(s)
Tagged: 0 Thread(s)
Quoted: 4131 Post(s)
Liked 760 Times in 418 Posts
The key fact from the opinion piece is this: "Dose sensitivity has been observed for every common acute viral infection that has been studied in lab animals, including coronaviruses." and "Humans also exhibit sensitivity to viral dose."
It would actually be surprising if CV19 in humans does not have dose sensitivity. That would make CV19 extremely unusual in yet another way, which of course is possible, but also goes against all anecdote that those who are getting high doses are getting sicker.
noisebeam is offline  
Old 04-18-20, 11:06 AM
  #17  
Tony P.
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 243
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 171 Post(s)
Liked 113 Times in 63 Posts
Originally Posted by noisebeam View Post
The key fact from the opinion piece is this: "Dose sensitivity has been observed for every common acute viral infection that has been studied in lab animals, including coronaviruses." and "Humans also exhibit sensitivity to viral dose."
It would actually be surprising if CV19 in humans does not have dose sensitivity. That would make CV19 extremely unusual in yet another way, which of course is possible, but also goes against all anecdote that those who are getting high doses are getting sicker.
Although not yet proven, it's reasonable to suggest that CV19 is not unusual in this regard. But dose quantity / sensitivity is a largely technical matter at this stage because people can't regulate their exposure. All I'm saying is someone can spend an hour in a store that has 10 coronavirus carriers without infection but become infected upon leaving by touching the door handle.

The issue becomes most relevant to healthcare workers where it's not technical but much more life and death.
Tony P. is offline  
Old 04-18-20, 11:44 AM
  #18  
rumrunn6
Senior Member
 
rumrunn6's Avatar
 
Join Date: Jul 2008
Location: 25 miles northwest of Boston
Posts: 24,865

Bikes: Bottecchia Sprint, GT Timberline 29r

Mentioned: 103 Post(s)
Tagged: 0 Thread(s)
Quoted: 3719 Post(s)
Liked 837 Times in 583 Posts
& until we know more it wud be irresponsible to send kids back to school. I think the MA governor should call it now. our infection & death rate is maintaining at a very high level
rumrunn6 is offline  
Old 04-18-20, 12:36 PM
  #19  
Tony P.
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 243
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 171 Post(s)
Liked 113 Times in 63 Posts
Originally Posted by rumrunn6 View Post
& until we know more it wud be irresponsible to send kids back to school. I think the MA governor should call it now. our infection & death rate is maintaining at a very high level
I can't speak on MA specifically but in essence you're spot on. Whatever may be gained can't be worth the risk. Schools are closed in many locations until mid-May already so at this stage it's best to let it play out.
Tony P. is offline  
Old 04-18-20, 06:57 PM
  #20  
79pmooney
A Roadie Forever
 
79pmooney's Avatar
 
Join Date: Oct 2014
Location: Portland, OR
Posts: 8,181

Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder

Mentioned: 98 Post(s)
Tagged: 0 Thread(s)
Quoted: 2187 Post(s)
Likes: 0
Liked 586 Times in 410 Posts
Originally Posted by Tony P. View Post
I'd say you may be correct but I doubt it. Is there anything to support your statement or is it just a theory? Clearly there's a correlation between age / race / certain preexisting conditions and health risk but I've seen nothing to suggest length of exposure relates to the degree of infection. It seems to me that if touching a handle could lead to severe exposure, it doesn't take much.
We can watch a lot of people die while waiting to see if more exposure increases risk.or severity. The rate of cases with severe symptoms among those on the the front lines is high. I've heard it being described as being like a war. Decided by many skirmishes with a lot of random factors. But more either individual skirmishes won or lopsided odds on fewer, the more likely one side is to prevail. (The virus vs the body's defenses.) Many of those on the front liners are resigned to the idea they are going to die. It's just a matter of when. I call them angels. Angels that are going tot pay the price for what they do. The rest of us can practice social distancing, wear masks and be responsible to keep their case load down and them living longer. Or we can practice the freedom that is the bedrock of this nation and condemn these angels we don't know to a quicker death. (Edited for typos)

Last edited by 79pmooney; 04-18-20 at 07:06 PM.
79pmooney is online now  
Likes For 79pmooney:
Old 04-19-20, 03:53 AM
  #21  
Tony P.
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 243
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 171 Post(s)
Liked 113 Times in 63 Posts
Originally Posted by 79pmooney View Post
We can watch a lot of people die while waiting to see if more exposure increases risk.or severity. The rate of cases with severe symptoms among those on the the front lines is high. I've heard it being described as being like a war. Decided by many skirmishes with a lot of random factors. But more either individual skirmishes won or lopsided odds on fewer, the more likely one side is to prevail. (The virus vs the body's defenses.) Many of those on the front liners are resigned to the idea they are going to die. It's just a matter of when. I call them angels. Angels that are going tot pay the price for what they do. The rest of us can practice social distancing, wear masks and be responsible to keep their case load down and them living longer. Or we can practice the freedom that is the bedrock of this nation and condemn these angels we don't know to a quicker death. (Edited for typos)
Absolutely, my point exactly but you said it much better than when I said:
The issue becomes most relevant to healthcare workers where it's not technical but much more life and death.
The issue of dose quantity sensitivity isn't important right now. It's up to us to avoid any level of risk to ourselves and thereby reduce the risk to everyone else.
Tony P. is offline  
Old 04-19-20, 10:32 AM
  #22  
wgscott
Occam's Rotor
 
wgscott's Avatar
 
Join Date: Jul 2013
Posts: 6,041
Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 2366 Post(s)
Liked 1,179 Times in 614 Posts
CA schools are closed for the rest of the school year, at least. The university summer school course I am to teach in August is already mandated to be on-line. This isn't going away any time soon.
wgscott is offline  
Old 04-19-20, 01:53 PM
  #23  
Tony P.
Senior Member
Thread Starter
 
Join Date: May 2015
Posts: 243
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 171 Post(s)
Liked 113 Times in 63 Posts
Originally Posted by wgscott View Post
CA schools are closed for the rest of the school year, at least. The university summer school course I am to teach in August is already mandated to be on-line. This isn't going away any time soon.
Boston University announced it may postpone opening until January 2021.
Tony P. is offline  
Old 04-19-20, 02:48 PM
  #24  
rumrunn6
Senior Member
 
rumrunn6's Avatar
 
Join Date: Jul 2008
Location: 25 miles northwest of Boston
Posts: 24,865

Bikes: Bottecchia Sprint, GT Timberline 29r

Mentioned: 103 Post(s)
Tagged: 0 Thread(s)
Quoted: 3719 Post(s)
Liked 837 Times in 583 Posts
Hoping our mid July vacation rental doesnít get canceled Iíd be out a thousand bucks I already gave them holding out on the 2nd thousand until 1 month prior which is not that far away Iím cautiously optimistic but actually not convinced weíre in the clear even if we isolate once we get there - I mean I can do the same thing there that I can do here in terms of staying away from ppl
rumrunn6 is offline  
Old 04-19-20, 05:15 PM
  #25  
Biker395 
Seat Sniffer
 
Biker395's Avatar
 
Join Date: Sep 2007
Location: SoCal
Posts: 4,983

Bikes: 2008 Scott CR1 Pro; 2006 Schwinn Fastback Pro and 1996 Colnago Decor Super C96; 2003 Univega Alpina 700; 2000 Schwinn Super Sport

Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 650 Post(s)
Liked 411 Times in 184 Posts
There is a lot of anecdotal evidence of incredibly high infection rates out there ... much higher than anticipated.

"This weekend, Massachusetts General Hospital researchers strolled around the working-class suburb of Chelsea (Boston). They approached people on the street and 200 of them agreed to be tested on the spot for SARS-CoV-2 IgG: 64 were positive (32%). Many of the people said, yeah, a couple of weeks ago I felt a little sick, I wondered if I had COVID? But none had actually tested positive for infection. Formally, Chelsea reported 719 cases and 39 deaths, which given their population of 40,000 or so would represent a confirmed prevalence of 2%. [Specificity of test: only 90%, meaning 10% false positives: adjusting downwards, 58/200 = 29%]- 15-fold lower."

__________________
Proud parent of a happy inner child ...

Biker395 is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.