Coronavirus

[heltok]

Today I realized that almost every epidemiologist has made a great error regarding R and herd immunity.

Let’s say R0=2.5. Then it’s a simple thought error to assume that 60% needs to be infected for herd immunity. However here is the error, populations are not uniform. For example R in NYC is gonna be higher than in Alaska. Let’s assume R=4 in NYC and 2 in Alaska, then herd immunity should be at 75% in NYC and 50% in Alaska. Wrong, populations are not uniform. Some people will interact with more people than other. For example young people vs retired people, bus drivers vs truck drivers, kindergarten teachers vs online English teachers etc. If in one city 10% of the people do 50% of the interacting then these people will get infected earlier in average and once they have immunity the city will get their R cut in half.

So the conclusion of this is that R will be higher early in the spread when the high interaction individuals get infected. Then it will naturally fall even with pretty low level of immunity.

 

[cwerdna]

Looks like all these protests are centrally organized. Its like tea party II.

Yes, probably the work of these pro-gun people:
Pro-gun activists using Facebook groups to push anti-quarantine protests
Who’s Behind the “Reopen” Domain Surge? — Krebs on Security

and then throw in nuts like Alex Jones of Infowars: Alex Jones shakes hands with protesters at Texas rally to reopen state against stay-at-home orders.

 

[Norbert]

Today I realized that almost every epidemiologist has made a great error regarding R and herd immunity.

Let’s say R0=2.5. Then it’s a simple thought error to assume that 60% needs to be infected for herd immunity. However here is the error, populations are not uniform. For example R in NYC is gonna be higher than in Alaska. Let’s assume R=4 in NYC and 2 in Alaska, then herd immunity should be at 75% in NYC and 50% in Alaska. Wrong, populations are not uniform. Some people will interact with more people than other. For example young people vs retired people, bus drivers vs truck drivers, kindergarten teachers vs online English teachers etc. If in one city 10% of the people do 50% of the interacting then these people will get infected earlier in average and once they have immunity the city will get their R cut in half.

So the conclusion of this is that R will be higher early in the spread when the high interaction individuals get infected. Then it will naturally fall even with pretty low level of immunity.

Interesting thought, sounds reasonable, however why would you think that this is not already part of the "formula" for herd immunity, assuming that this formula was already subject to the test of time?

EDIT: R_effective (or R_t) of course decreases as herd immunity is approached.

 

[heltok]

Interesting thought, sounds reasonable, however why would you think that this is not already part of the "formula" for herd immunity, assuming that this formula was already subject to the test of time?

EDIT: R_effective (or R_t) of course decreases as herd immunity is approached.

I have heard a lot people claiming that we need ~66% of people infected to get herd immunity, don’t think I have ever heard anyone say we need 66% interactions immune to get herd immunity. The point is that this is not the same. If NYC/Stockholm has 20% people with antibodies already, and if these people have an above average level of interactivity, this could explain a previous/current explosive growth. Also ~2weeks later R could be much lower even before effects of additional social distancing. There might not be be a need of going above 50% infected, as long as it’s the “right ones” getting infected.

 

[dfwatt]

This is an excellent read from a couple of JHU epidemiologists.
I probably say excellent because I agree with them almost point by point.

Yes that is an excellent summary pitched at a bright lay person level. Exactly what most people need to read.

 

[NicoV]

On April 14, 4.3 percent of the Belgian population had Covid-19 antibodies. The percentage doubled compared to 2 weeks earlier.
The tests come from a systematic test of blood donations, and is considered very representative.
Immuniteit Belgische bevolking verdubbeld in twee weken: 4,3 procent heeft antistoffen

 

[linux-works]

here's a guy explaining how the 're-opening' in his state is actually going to hurt more than it helps:

I see his point and agree with it.

states that force people into this are evil states. sadly, we have a LOT of evil states in the US ;(

 

[linux-works]

Yes, probably the work of these pro-gun people:
Who’s Behind the “Reopen” Domain Surge? — Krebs on Security

I do trust krebs and its really telling about the domain registrations.

again, the dumb are being manipulated by the powerful; and, as always, they are absolutely unaware that they are, in fact, being used as pawns in game of life (mongo agrees, btw). actively working against their own best interests - and damned glad to be doing it, too! so upsetting to see people conned like that ;(

 

[linux-works]

wow, its so obvious now:

in a browser, enter reopenpa.com and it immediately redirects to

End Wolf's Shutdown - Pass SR323/HR836 and ReOpenPA.com!

does not even TRY to hide the redirect.

(or maybe my browser is very old, which is actually is; and most JS is disabled by default).

 

[kbM3]

Nice interview with a Hong Kong epidemiologist.

Concise, clear and thoughtful.


Corona: "You Need the Sledgehammer" To Bring Down Infections - DER SPIEGEL

Basically you need to straddle an Rt of roughly one for most of the next 12-18 months. A state starting now to relax social distancing to allow their Rt to increase to 1 with 1000 new infections per day will maintain that daily infection rate for the next 12-18 months. Whereas if that state can maintain this hammer for another 1 month, they might only face 100 new infections / day for the subsequent 11-17 months with the exact same social distancing protocol of straddling Rt = 1.

 

[mikevbf]

Here is a summary of NewYork-Presbyterian Hospital's update from yesterday:

"The president has proposed something that "literally makes no sense", it would be much better if he let the medical advisers focus on what matters.

Thousands have tested with the antibody test. About 1 in 5 of those have had exposure to covid.

Today: 1,887, with 652 of those on ventilators. We have had well over 5,000 patients discharged.

Northwell has released some observational studies, we will do so soon.

Therapies: no proven therapies.

Over time we are going to be expanding the PCR test to more healthcare workers, more to come on Monday.

We will be expanding the antibodies test over time, right now just for healthcare workers.

We will also be expanding patient PCR testing, including those who may be asymptomatic and mild symptoms."

 

[OPRCE]

This is brilliant:

Sarah Cooper on Twitter

Also this one:

SupiraPupiraBut on Twitter

 

[MXLRplus]

Literally makes no sense? Thinking that giving away nearly $3 trillion dollars, mostly to millionaires and billionaires is going to protect those at the highest risk of Covid or help workers makes no sense. That is a far greater folly than sound bites about inventing drug that could target the virus itself much like a disinfectant is used. Businesses that actaully need paycheck support aren't going to get it. It's too late for tens of thousands of businesses or you would not see the unemployment numbers we do. Communities that are hardest hit by C19 are being cut checks to residents. What are they going to do with it? Buy unavailable PPE or testing? Unavailable products?

And with that I humbly bow out of this thread. The NYP Hospital report was one of the last few apolitical data sources. Now that it's coverting over to a campaigning program, there's not much left that actually has anything to do with C19, Tesla, Lifesaving, or Financial Recovery.

 

[AlanSubie4Life]

, since I wouldn't expect testing or actual cases to make such a jump in a single day

Testing increase to 223k. Likely not an actual new peak. Good to see testing rising. We need to get to 500k-1 million per day.

I didn't follow how you came to use 16162+4000 = 20k deaths for New York State

NY State website. Does not count presumed deaths probably.

 

[Daniel in SD]

Interesting case study from a South Korean call center. There seems to be a common thread to these super spreader cases. Being in enclosed spaces for with lots of people, especially if they are being vocal, is very bad. It's interesting that this study found only 1.9% asymptomatic cases after 14 days of testing positive and the asymptomatic cases didn't spread it to any household members.
Coronavirus Disease Outbreak in Call Center, South Korea

Abstract
We describe the epidemiology of a coronavirus disease (COVID-19) outbreak in a call center in South Korea. We obtained information on demographic characteristics by using standardized epidemiologic investigation forms. We performed descriptive analyses and reported the results as frequencies and proportions for categoric variables. Of 1,143 persons who were tested for COVID-19, a total of 97 (8.5%, 95% CI 7.0%–10.3%) had confirmed cases. Of these, 94 were working in an 11th-floor call center with 216 employees, translating to an attack rate of 43.5% (95% CI 36.9%–50.4%). The household secondary attack rate among symptomatic case-patients was 16.2% (95% CI 11.6%– 22.0%). Of the 97 persons with confirmed COVID-19, only 4 (1.9%) remained asymptomatic within 14 days of quarantine, and none of their household contacts acquired secondary infections. Extensive contact tracing, testing all contacts, and early quarantine blocked further transmission and might be effective for containing rapid outbreaks in crowded work settings.

Time to open the gyms and restaurants?

 

[AlanSubie4Life]

. It's interesting that this study found only 1.9% asymptomatic cases after 14 days of testing positive and the asymptomatic cases didn't spread it to any household members.

Yes. This is the sort of data we really need to keep gathering, rather than rather credulous articles about high numbers of asymptomatics with no detail or follow up.

We really need to know how contagious true asymptomatics are. Though to be honest we just need to be able to identify all positive cases and contact trace, regardless.

Hopefully on the carrier TR they’ll really drill down on asymptomatic rates, and how they change with time.

 

[linux-works]

looking at the 'blue desks' (infected people) scares the crap out of me, in terms of the 'open office' concept that still shows no signs of going away, in corp USA.

has anyone heard ANY talk, from their employers, about making more room between desks, maybe the return of the cubicle barrier, perhaps?

my guess is that they are all to afraid to lose that sweet, sweet control they get with (most horrible) 'open office' design. it saves them money, it scares the employees, it establishes a culture that has more negatives than positives, but employers don't want to admit they were wrong, all along, about this.

anyone seeing any signs of movement in their workplace discussions? anyone HAVING any workplace discussions like this?

 

[SageBrush]

Interesting case study from a South Korean call center. There seems to be a common thread to these super spreader cases. Being in enclosed spaces for with lots of people, especially if they are being vocal, is very bad.

EXACTLY

This is why I worry about essential services in buildings with poor air exchange or A/C without HEPA.

 

[SageBrush]

looking at the 'blue desks' (infected people) scares the crap out of me, in terms of the 'open office' concept that still shows no signs of going away, in corp USA.

has anyone heard ANY talk, from their employers, about making more room between desks, maybe the return of the cubicle barrier, perhaps?

my guess is that they are all to afraid to lose that sweet, sweet control they get with (most horrible) 'open office' design. it saves them money, it scares the employees, it establishes a culture that has more negatives than positives, but employers don't want to admit they were wrong, all along, about this.

anyone seeing any signs of movement in their workplace discussions? anyone HAVING any workplace discussions like this?

You are trying to ride the Covid horse to pursue an agenda.

Look at schools in Asia that have very little Covid. They have ~ head high barriers between sitting children. That is enough. However, I'm willing to bet those rooms have good ventilation.

 

[jerry33]

looking at the 'blue desks' (infected people) scares the crap out of me, in terms of the 'open office' concept that still shows no signs of going away, in corp USA.

has anyone heard ANY talk, from their employers, about making more room between desks, maybe the return of the cubicle barrier, perhaps?

my guess is that they are all to afraid to lose that sweet, sweet control they get with (most horrible) 'open office' design. it saves them money, it scares the employees, it establishes a culture that has more negatives than positives, but employers don't want to admit they were wrong, all along, about this.

anyone seeing any signs of movement in their workplace discussions? anyone HAVING any workplace discussions like this?

You have to bear in mind that in corporate America, employees are considered to be criminals and need to be made aware of that frequently (as always, there are a few exceptions). Hence the open office concept.