Some New Science on Virus Transmission on Airplanes

[Dockhead]

Originally Posted by Singularity

Further on this, and I couldn't find methodology for the model below, but I'd suggest that the staff of nursing homes generally do more dirty work, more patient contact time, less educated, and frankly more likely have pre-existing conditions themselves, less healthy population vs hospital staff population.

https://www.cdc.gov/vaccines/acip/me...08-Dooling.pdf
https://www.cdc.gov/vaccines/acip/me...06-Slayton.pdf

Sure, but maybe it's much simpler than that -- the staff circulate among the patients much more than the patients circulate among each other. So they are simply a much larger vector of transmission, than the patients themselves. If you can stop the staff from passing the virus to the patients, then you've stopped most of the spreading. I think that's the idea.

[Auspicious]

Originally Posted by Dockhead

Have you heard of the 80/20 rule?

The 80/20 and 90/10 "rules" are apocryphal and show up over and over again in many fields of endeavor. The concept is useful but the numbers can't be used for deterministic analysis.

[Dockhead]

Originally Posted by Auspicious

The 80/20 and 90/10 "rules" are apocryphal and show up over and over again in many fields of endeavor. The concept is useful but the numbers can't be used for deterministic analysis.

The so-called "80/20 Rule", or the Pareto Principle, is not exactly a "rule", but is certainly not apocryphal. It describes, at least roughly, an amazing number of different phenomena. I believe it is derived from the characteristic shape of power-law distribution curves, see here: https://en.wikipedia.org/wiki/Pareto_distribution. It's striking only because it's counter-intuitive.

"The Pareto principle or "80-20 rule" stating that 80% of outcomes are due to 20% of causes was named in honour of Pareto, but the concepts are distinct, and only Pareto distributions with shape value (α) of log45 ≈ 1.16 precisely reflect it. Empirical observation has shown that this 80-20 distribution fits a wide range of cases, including natural phenomena and human activities." https://en.wikipedia.org/wiki/Pareto_distribution

Observed strikingly in different aspects of epidemiology:

https://www.nature.com/articles/s41591-020-1092-0

"We identified 4–7 SSEs across 51 clusters (n = 309 cases) and estimated that 19% (95% confidence interval, 15–24%) of cases seeded 80% of all local transmission. . . .

"From these estimates we inferred that 17–19% (cluster size model and observed offspring distribution, respectively) of SARS-CoV-2 infections were responsible for 80% of all transmission events in Hong Kong, while 69% of cases did not infect anyone. . . "

[Auspicious]

Originally Posted by Dockhead

It's striking only because it's counter-intuitive.

Anyone who has worked in personnel management doesn't find it counter intuitive at all, although the ratio is more like 98 - 2. *sigh* People don't scale well.

[GordMay]

Originally Posted by Dockhead

Potential superspreaders might also be that small number of people who because of their work have a great deal more social contact than other people...

Indeed.
The Pareto Principle, or the 80/20 rule, states that, for many phenomena 80% of the result comes from 20% of the effort. Simply stated, most of the time, things are distributed unevenly.
Pareto’s principle is more of an observation, than a full-fledged scientific theory. It is commonly noticeable in a variety of contexts, but it’s not applicable to each and every scenario. Plus, the numbers 80 and 20 should not neccesaarily be added up to 100.

The fact it’s called the 80/20 rule is a simply a catchy, historical catchphrase.
The principle was named after Vilfredo Pareto, an Italian economist, who, back in the nineteenth century, noticed that about 80% of Italy’s land belonged to 20% of the country’s population.

According to a recent (Sept 2020) paper*, it is estimated that 20% of Covid-19 cases were responsible for 80% of local transmission. This means most people won't infect too many other people, but rather there exist so-called superspreaders (and superspreding events) that cause many more to fall ill. Take Patient 31 for example; a Korean churchgoer, who tested positive, and attended mass, reportedly transmitting the coronavirus onto a thousand fellow worshipers.

The promise of being able to deliver 80% of the goal, by focusing on 20% of the activities, does look enticing.
The problem is: How to identify the vital few?

*“Clustering and superspreading potential of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in Hong Kong” ~ by Dillon Adam et al
➥ https://www.nature.com/articles/s41591-020-1092-0


I see that Dockhead was way ahead of me.

[Auspicious]

Originally Posted by GordMay

According to a recent (Sept 2020) paper*, it is estimated that 20% of Covid-19 cases were responsible for 80% of local transmission. This means most people won't infect too many other people, but rather there exist so-called superspreaders (and superspreding events) that cause many more to fall ill. Take Patient 31 for example; a Korean churchgoer, who tested positive, and attended mass, reportedly transmitting the coronavirus onto a thousand fellow worshipers.

The promise of being able to deliver 80% of the goal, by focusing on 20% of the activities, does look enticing.
The problem is: How to identify the vital few?

Here in Maryland USA state contact tracing indicates that the following venues, in order, are the most common superspreader events: 1. family events including backyard barbecues, weddings, and funerals; 2. bars and restaurants; and 3. large in-person events, particularly church and sporting events.

So at least here in Maryland your family could kill you, going out to eat and drink (including tents in parking lots) is unwise, and church is bad for you.

[Dockhead]

Originally Posted by Auspicious

Anyone who has worked in personnel management doesn't find it counter intuitive at all, although the ratio is more like 98 - 2. *sigh* People don't scale well.

ROTFLMAO.

[Auspicious]

Originally Posted by Dockhead

ROTFLMAO.

Actually the best number is likely similarly apocryphal from J. Edwards Deming who said that you need the square number of a total workforce to understand and buy into organizational vision to succeed.

Not sure how or if that applies to COVID.

[valhalla360]

Originally Posted by Singularity

I and others have multiple, emphasize multiple times explained that the "assuming the priority groups are chosen wisely" is not possible. Wise = knowing what/where/when/how. Are you trolling?

Tell us....please tell the world how you've figured out who the 1 to 2 superspreaders out of 10 people will be. While you're at it, go ahead and take over the world with your methodology of determining pareto distributions in chaotic systems.

Of course everyone agrees that if we knew precisely who they were, it'd be a top priority. But even then, if "economic recovery = people going out buying stuff, jobs increasing" then it's still debatable if principally targeting superspreaders will more better bring about economic recovery when death counts are still up on the news.

My apologies if I'm read as rude, but this is tedious. It's been explained multiple times multiple ways. And some point I'm wondering if you're trolling for fun.

It does get tedious, I agree. You seem to be thinking in terms of picking out a specific individual. If you put 10 people in a room and say pick the super spreader...with no other information, of course, you are correct.

But we are talking about groups of millions of people and playing the odds. Yes, the stray super spreader will slip thru but it's well established, close physical activities with multiple people are the most likely place for super spreader events. So if we target those who have lots of close physical contact with many people (particularly new people), we will disproportionately vaccinate the super spreaders. If we eliminate 90% of the potential super spreaders by vaccinating 20% of the population, that far more effective (and a wise approach).

Medical staff in particular have a second layer on top in the sense that they are not only interacting at close proximity with many random people per day, they are more likely to be interacting with both infected individuals and individuals most likely to have sever reactions to the virus.

If it was all a crap shoot, they wouldn't be prioritizing who gets the vaccine first.

[valhalla360]

Originally Posted by Auspicious

I offer without substantiation that superspreaders fall into one of two categories: those who truly shed more virus than the average person and stupid people. Stupid people eschew masks and distancing, go to large gatherings, and in general behave in ways that run counter to societal good and to their own well-being.

There might be some truth to people who shed more virus but...

A stupid person shedding virus like mad won't infect anyone if he lives and works along with little to no interaction with others.

On the other hand, someone who is in close physical contact with 100s of people per day can be a super spreader even if they shed only moderate amounts of the virus.

We can't predetermine who will shed a lot of virus but we can figure out which groups have lots of physical contact with many people.

[Auspicious]

Originally Posted by valhalla360

A stupid person shedding virus like mad won't infect anyone if he lives and works along with little to no interaction with others.

I was correlating attending large events with being stupid.

[valhalla360]

Originally Posted by Auspicious

I was correlating attending large events with being stupid.

So the staff working the emergency room are stupid because it's a large event? Of course not.

Agreed it's hard to isolate some behaviors but attending a large public event is only one potential super spreader vector.

Identifying jobs likely to result in super spreaders is much easier.

Again, it's playing the odds. You won't hit it 100% but even if you hit 50% of the super spreaders in the first 20% distributed, that's a huge improvement in efficiency at getting the spread to slow down.

Think of it like counting cards at Black Jack. You aren't guaranteed to win any specific hand but if you do it right, you will win a lot more. Pointing to the losing hands doesn't invalidate the effectiveness.

[Auspicious]

Please look up hyperbole.

[valhalla360]

Originally Posted by Auspicious

Please look up hyperbole.

Right after you look up "relevant", I'll get on it.

[Midnight Son]

Originally Posted by Dockhead

Sure, but maybe it's much simpler than that -- the staff circulate among the patients much more than the patients circulate among each other. So they are simply a much larger vector of transmission, than the patients themselves. If you can stop the staff from passing the virus to the patients, then you've stopped most of the spreading. I think that's the idea.

Sorry, because the staff in Care Homes are paid less, than hospital workers, at least in my area, they have to work extra jobs, usually in another Care Home. Therefore virus spread!