The Corona Virus

[veti]

IGiven the ease of spread, long incubation time, and lack of obvious symptoms in a lot of people, I'm not confident that targeted testing/contact tracing can be done.

Tell that to South Korea, Germany, New Zealand. It absolutely can be done, right up to the point where the numbers of people needing to be tested exceeds the testing capacity available. That's why testing capacity is such a big deal, and the outbreak has to be caught early while the absolute numbers are still relatively low.

Can it be done in countries like the USA or Spain or UK right now? No. There are way too many cases, and not nearly enough resources to trace and test everyone. But one lesson of this pandemic - if anyone is actually willing to learn at all, rather than simply insisting that they were right all along and their opponents were criminally irresponsible idiots, which is what it looks like most politicians (and, in microcosm, we here in this thread) seem to be doing right now - is that preparation pays off. Get your testing procedures and materials in place before you get your first case, get quarantine rules in place before it breaks out into the community, and it can be contained even with those difficult attributes you mention.

[Liquor Box]

Tell that to South Korea, Germany, New Zealand. It absolutely can be done, right up to the point where the numbers of people needing to be tested exceeds the testing capacity available. That's why testing capacity is such a big deal, and the outbreak has to be caught early while the absolute numbers are still relatively low.

Can it be done in countries like the USA or Spain or UK right now? No. There are way too many cases, and not nearly enough resources to trace and test everyone. But one lesson of this pandemic - if anyone is actually willing to learn at all, rather than simply insisting that they were right all along and their opponents were criminally irresponsible idiots, which is what it looks like most politicians (and, in microcosm, we here in this thread) seem to be doing right now - is that preparation pays off. Get your testing procedures and materials in place before you get your first case, get quarantine rules in place before it breaks out into the community, and it can be contained even with those difficult attributes you mention.

I'm from New Zealand, and I don't think it is our testing capacity which saw a reduction in virus numbers. There are people who report symptoms who didn't get tested. Our testing per capita is about 1.5 times USA, and less per capita than Italy.

The reason the virus has dropped off here is because we started getting cases a long time after most of the rest of the world, so we were able to respond before it got out of hand. We responded by locking everyone down except for essential workers, so we are not allowed to leave our homes (for five weeks now and counting). We are also fortunate to relatively sparsely populated which means the frequency of transmission is lower.

Assuming the virus is eliminated here, and we are all allowed to leave our homes again, it is not clear that we are safe. The virus remains rampant overseas, and it could easily be reintroduced here. While we will try to close our borders, even for an island nation that is impossible to do completely.It is likely the virus will remain at large worldwide for some time, so we are aware that its entirelypossible that there will be an additional outbreak here meaning all our efforts to eradicate it locally were in vain.

[Ibrinar]

This evidence points to one of two things: either the disease is really good at killing people, or the lock-downs didn't do anything. Without the proper scientific studies I doubt we will ever know which is the truth.

No offense but that is a silly take. We can see doubling speed in different regions and that it has slowed down with lock down (and some are long enough in lock down to have that happen with death counts which is more reliable) we can also see death per million in the hardest hit regions and notice from the vast difference to milder region that the milder region aren't slowing down because of the virus running out of uninfected host.

Take germany it stands at 77 death per million and there is a clear downward trend for both new detected infected and daily death and active cases have been dropping for a while now. Then we look at NYC a city with a population of 8.4 million which gives its count as 12k confirmed and 5k probable death and notice that even just with the confirmed count there is almost a factor of 20 between their death per million numbers so it is safe to say something slowed the spread that isn't saturation of the population. What do you suggest as explanation that doesn't involve the lock down in germany doing anything?

How strong the effect exactly is and which individual measures (from closing big events to home office when possible to closing restaurants and many shops to social distancing) contribute how much and how the different variants in different countries (or parts of countries) compare, that is hard to say. That the measures as a whole have vastly slowed the spread in many places has a good amount of data to support it.

Tell that to South Korea, Germany, New Zealand. It absolutely can be done, right up to the point where the numbers of people needing to be tested exceeds the testing capacity available. That's why testing capacity is such a big deal, and the outbreak has to be caught early while the absolute numbers are still relatively low.

Not sure I would list germany, it already has spread far enough that (unless we manage to sustain measures until the numbers get even smaller) I am not optimistic we can handle the new spread with contact tracing. But would be nice.

[Liquor Box]

Take germany it stands at 77 death per million and there is a clear downward trend for both new detected infected and daily death and active cases have been dropping for a while now. Then we look at NYC a city with a population of 8.4 million which gives its count as 12k confirmed and 5k probable death and notice that even just with the confirmed count there is almost a factor of 20 between their death per million numbers so it is safe to say something slowed the spread that isn't saturation of the population. What do you suggest as explanation that doesn't involve the lock down in germany doing anything?

NYC would have significantly higher population density and therefore presumably greater transmission risk.

There are a lot of factors influencing the different outcomes. I'm not sure which of the two (Gernamny and NYC) have the older population, the greater incidence of exacerbating conditions or better healthcare or more cultural emphasis on handwashing, but you'd expect those to be factors as well.

You may be right that isolation has played a role in Germany (it makes sense that it would help at least somewhat) but I don't think the causal connection is as certain as your post seems to suggest.

[halfeye]

NYC would have significantly higher population density and therefore presumably greater transmission risk.

Germany has cities, many big cities. I don't think population density is a significant factor.

[NotASpiderSwarm]

Germany has cities, many big cities. I don't think population density is a significant factor.

NYC has a population density of 10,000 people per sq km. I looked up the 10 largest cities in Germany, the highest was Munich at 4,700 per sq km*. Most are around 3,000 people per sq km. NYC also has 8.4 million people total, while Berlin is a mere 3.7 million. That much humanity in that small an area makes things work very differently in NY than they do anywhere else.

*For reference, London is 5,666 per km, Rome is 5,800 per km, and Tokyo is 6,350 per km. New York is wildly vertical.

[georgie_leech]

Germany has cities, many big cities. I don't think population density is a significant factor.

Germany's densest city is Munich, about 4500-ish people/km² depending on when you're measuring. That's less half the density of NYC, about 10000 people/km². The same goes for Berlin's ~4000, and from there the next most dense cities top out at ~3000.

I doubt it's the only factor, but I'd be shocked if that density didn't make a difference in spreading rates.

Edit:Ninja'd

[Grey_Wolf_c]

NYC has a population density of 10,000 people per sq km. I looked up the 10 largest cities in Germany, the highest was Munich at 4,700 per sq km*. Most are around 3,000 people per sq km. NYC also has 8.4 million people total, while Berlin is a mere 3.7 million. That much humanity in that small an area makes things work very differently in NY than they do anywhere else.

*For reference, London is 5,666 per km, Rome is 5,800 per km, and Tokyo is 6,350 per km. New York is wildly vertical.

And Athens is 20000 people per square km, and Paris 21k. There is no real correlation between density and how bad the infection is - France is mid-to-bad, Greece is doing amongst probably the best in EU, while England with it's "low" 4500 people/km2 London is atrocious.

A much better indicator? Tourist per year. Very touristy places, that gets lots of international travel, got infected earlier and where harder to track. Regardless of density. But even that is at best a rough estimate.

Grey Wolf

[Rockphed]

And Athens is 20000 people per square km, and Paris 21k. There is no real correlation between density and how bad the infection is - France is mid-to-bad, Greece is doing amongst probably the best in EU, while England with it's "low" 4500 people/km2 London is atrocious.

A much better indicator? Tourist per year. Very touristy places, that gets lots of international travel, got infected earlier and where harder to track. Regardless of density. But even that is at best a rough estimate.

Grey Wolf

The death rate in NYC is about 7000 per million inhabitants. NYC has the fun of being almost entirely the built up core of a city: all the less densely populated areas are in other jurisdictions. I suspect that getting at the same densely populated core of other cities we might see similar spikes in deaths.

[Ibrinar]

Edit: Where are you getting 7000 from Rockphed?

NYC would have significantly higher population density and therefore presumably greater transmission risk.

There are a lot of factors influencing the different outcomes. I'm not sure which of the two (Gernamny and NYC) have the older population, the greater incidence of exacerbating conditions or better healthcare or more cultural emphasis on handwashing, but you'd expect those to be factors as well.

You may be right that isolation has played a role in Germany (it makes sense that it would help at least somewhat) but I don't think the causal connection is as certain as your post seems to suggest.

Population density plays a role in transmission speed but happens to be of limited importance to my argument. We have seen before that it can spread with a significant R in Germany. If the connections between people were randomly distributed 5% immune would only reduce the R by 5%. They aren't of course some have many more daily contacts than others so a low number of immune people could have an oversized impact (though in return they would spread it to many people first). Consider how high of an impact do you consider realistic? By what factor might the small group of immune people over perform in reducing the infected per person?

If you have a number please consider that it isn't evenly distributed in germany either. While between NYC and germany there is a factor 20 between Germany and one of its states there is another factor 7.5 . Mecklenburg Vorpommern is at 10 death per million.

Or perhaps more interestingly the densest city of germany is Munich with 12090/sq mi, sure less than half compared to NY (though part of NY, staten island has 2/3 of that density and is at 1270 death per million) but high compared to the rest of germany and it is above the average with 113 death per million. If going from the whole country to the densest city you only get 50% more death I do not believe that it is credible to attribute an order of magnitude difference for the point where the spread stops naturally (if we assume measures did nothing) to NYC's density.

Also we shouldn't forget that as a whole the USA is less densely populated. Yes much of the US population (like much of germany's population) is in the cities so a better number would be the median or average population density experienced by people but still.

Lastly it bears mentioning that the mechanic in which Corona spreads isn't unique and we should see similar spread patterns elsewhere. If you can expect an order of magnitude difference in proportional death count between Munich and NYC epidemiologists should be well aware.

As for demographics there are differences but I don't thinh they are big enough to account for such a big difference. As an example 17.88% of germans are aged 65+ https://www.baruch.cuny.edu/nycdata/...stribution.htm against 14.4% in NYC. With a median age of 47 for germany and 36.6 for NYC. So age wise NYC has the clear advantage. Obesity might be a factor (though sadly germany has the worst stats in europe there). Germany is at 54.8% overweight or obese (or 60.5% limited to adults of which 25% are obese) NYC is similiar with 34% overweight 22% obese

I won't go over the various risk factors feel free if you know of a difference that would account for a drastic difference. I think beyond the extreme density the demographics aren't that extremely different.

[Wardog]

Regarding comparing the lethality of cv19 vs flu:
There are undoubtably people who have caught cv19 but had mild or no symptoms and so have not been counted in the official statistics, meaning the lethality is probably less than the statistics imply.

But is that not true for flu as well?

So saying "we can't know if this is really worse than the flu until we do mass bloodtests" isnt really meaningful if we don't also do as rigorous testing for flu.

[Ibrinar]

Btw an attempt to estimate the economic impact of structured lockdown vs no action https://www.cnbc.com/2020/04/29/coro...ic-damage.html if anybody else finds that interesting. I haven't seen much of that but maybe I just haven't looked properly. (Though I expect any estimates to have massive error bars.)

And for random curiosity corona news https://www.nature.com/articles/d41586-020-00965-x apparently the lock down is visible in seismic data. ^^

[Liquor Box]

Germany has cities, many big cities. I don't think population density is a significant factor.

Sure, and if we were comparing infection death rates between a particular German city and NYC, then it wouldn't be clear which had the higher population density (without checking). But the comparison made was between Germany as a whole and NYC, and NYC would clearly have the higher population density.

Edit: Actually i see from others posts that it would be clear - NYC would still have the higher density if we were comparing cities. But more importantly the comparison made was between a country and a city, where population density would be expected to be markedly different.

[Rockphed]

Edit: Where are you getting 7000 from Rockphed?

I remembered reading it somewhere. When I looked it up I found that it was closer to 1.5k per million (~12,000 deaths among ~8 million people). Which is still 50% worse than detroit's county, but not excessively so. NYC still accounts for nearly a quarter of the wuhan deaths in the USA.

[Lvl 2 Expert]

And Athens is 20000 people per square km, and Paris 21k. There is no real correlation between density and how bad the infection is - France is mid-to-bad, Greece is doing amongst probably the best in EU, while England with it's "low" 4500 people/km2 London is atrocious.

A much better indicator? Tourist per year. Very touristy places, that gets lots of international travel, got infected earlier and where harder to track. Regardless of density. But even that is at best a rough estimate.

Grey Wolf

I thought you just said both Paris and Greece are doing pretty well?

Honestly the better indicator is probably ****ty luck, where the virus happened to land and spread before measures were taken. In the Netherlands the hotspot is a bunch of relatively small communities pretty much boxed in between several cities, but it's those smaller towns where the peak of the infections sits. Because that's where a few infected winter sports groups that had been in Austria came home to and then joined the carnaval parties.

I agree New York had a higher chance of an outbreak than say Flint Michigan through a combination of total population, population density, number of people living there who can afford travel, visiting travelers both for business and tourism etc, but to start blaming any one of those factors?

(Population density numbers in general are also pretty deceiving, they can be highly different depending on exactly which areas are counted. I'm sure I could find a way to make Tokyo score higher than New York.)

[Ibrinar]

Sure, and if we were comparing infection death rates between a particular German city and NYC, then it wouldn't be clear which had the higher population density (without checking). But the comparison made was between Germany as a whole and NYC, and NYC would clearly have the higher population density.

Edit: Actually i see from others posts that it would be clear - NYC would still have the higher density if we were comparing cities. But more importantly the comparison made was between a country and a city, where population density would be expected to be markedly different.

To be clear I wasn't comparing infection death rates, I was comparing death per millions as proxy for how much of the population is still uninfected. (Which yes assumes similiar ifr.)

[veti]

I'm from New Zealand, and I don't think it is our testing capacity which saw a reduction in virus numbers. There are people who report symptoms who didn't get tested. Our testing per capita is about 1.5 times USA, and less per capita than Italy.

The testing capacity may not be world class, but it doesn't have to be because the numbers are so low, both absolutely and proportionally. It's good enough (at least I hope it is). Sure, we've tested, what, 2% of the population? Probably less, in fact, because of repeat subjects. But barely 2% of those tests were positive, and for at least a couple of weeks now all of those have been linked to known clusters. If the virus were out in the community, the proportion of positive tests would be a lot higher.

Yes, there are people who report symptoms and are counted as "presumed" cases without testing. When someone who's already living with a known case develops the same symptoms, it seems superfluous to test them. After all, the test is (by all accounts) quite an unpleasant process - why subject them to that, just to confirm what we're already pretty sure of, when it won't make any difference to anything anyway?

(For comparison, in the worse-hit countries, like the USA, France, Italy, UK, Spain, the percentage of tests returning positive is in the region of 15-20%. That means their testing capacity is nothing like enough to attempt a contact-tracing strategy. Germany and Canada have about 6% positives, South Korea less than 2%.)

[Liquor Box]

To be clear I wasn't comparing infection death rates, I was comparing death per millions as proxy for how much of the population is still uninfected. (Which yes assumes similiar ifr.)

Yeah, but my point was that NYC being a densely populated city means that the risk on infection is likely to be higher, and the rate of infection being higher is likely to increase the death rate (or death per million).

All I am really saying is that there a lot of factors that go into Covid infection rates (and by extension death rates), so I don't think it is as simple as saying country A has a higher death rate than country (or city) B, and that must be because it responded better.

The testing capacity may not be world class, but it doesn't have to be because the numbers are so low, both absolutely and proportionally. It's good enough (at least I hope it is). Sure, we've tested, what, 2% of the population? Probably less, in fact, because of repeat subjects. But barely 2% of those tests were positive, and for at least a couple of weeks now all of those have been linked to known clusters. If the virus were out in the community, the proportion of positive tests would be a lot higher.

Yes, there are people who report symptoms and are counted as "presumed" cases without testing. When someone who's already living with a known case develops the same symptoms, it seems superfluous to test them. After all, the test is (by all accounts) quite an unpleasant process - why subject them to that, just to confirm what we're already pretty sure of, when it won't make any difference to anything anyway?

(For comparison, in the worse-hit countries, like the USA, France, Italy, UK, Spain, the percentage of tests returning positive is in the region of 15-20%. That means their testing capacity is nothing like enough to attempt a contact-tracing strategy. Germany and Canada have about 6% positives, South Korea less than 2%.)

About 1% of our cases are positive. Certainly here there has been widespread commentary (including from health officials) that our testing capacity is insufficient.

I think the main the rate of infection here has decreased is that we shut the country down for several weeks. Your mileage may vary on whether that was worth it. That may become more apparent in a few years, with the benefit of hindsight, when we see if the virus flares up again.

[veti]

About 1% of our cases are positive. Certainly here there has been widespread commentary (including from health officials) that our testing capacity is insufficient.

Of course health officials would say that, that's their job. I bet they could be testing the entire population of the country every month, and they'd still be moaning that they couldn't do it every day.

But when there are 99 negative tests for every positive one, in what sense is there "not enough" testing capacity? You want to make it 199 to 1? How much would be "enough"?

[NichG]

Well, if you could test the entire population of a country once per the interval between exposure and becoming able to transmit, you could almost totally end Covid in that country within a single disease cycle of targetted quarantine (with perhaps a second pass for HCPs who can't avoid exposure as they'd be working with the infected)

So I guess figure out how much it'd be worth, vs how much it'd cost. It's probably something like a couple trillion dollars to implement globally - e.g. a few hundred dollars of testing per person. What's the economic impact of a month of Covid?

[Liquor Box]

Of course health officials would say that, that's their job. I bet they could be testing the entire population of the country every month, and they'd still be moaning that they couldn't do it every day.

But when there are 99 negative tests for every positive one, in what sense is there "not enough" testing capacity? You want to make it 199 to 1? How much would be "enough"?

Well I suppose there would be enough if almost nobody was refused a test who actually turned out to have the virus. That's happened, although I have no idea of the stats.

Maybe we are making the same point? You are saying our testing was sufficient for our purposes. I am saying that it was relatively sufficient because the virus arrived here late and we were well aware of it at a point were our numbers of infected were low.

Well, if you could test the entire population of a country once per the interval between exposure and becoming able to transmit, you could almost totally end Covid in that country within a single disease cycle of targetted quarantine (with perhaps a second pass for HCPs who can't avoid exposure as they'd be working with the infected)

So I guess figure out how much it'd be worth, vs how much it'd cost. It's probably something like a couple trillion dollars to implement globally - e.g. a few hundred dollars of testing per person. What's the economic impact of a month of Covid?

It probably wouldn't even be possible in the short term, no matter how much you throw at it. You'd probably have to teach people to test themselves.

How much the virus costs the economy probably varies dramatically depending on how a country reacts to it. Some shut down, some try to work through it, and everywhere in between.

[NichG]

It probably wouldn't even be possible in the short term, no matter how much you throw at it. You'd probably have to teach people to test themselves.

How much the virus costs the economy probably varies dramatically depending on how a country reacts to it. Some shut down, some try to work through it, and everywhere in between.

Unfortunately the returns for a lot of responses to a pandemic are a lot higher for coherent responses than varied ones. Half the countries wiping out Covid while the other half do nothing is far less than half as useful as everyone wiping it out. Its a large scale game of prisoner's dilemma.

[Liquor Box]

Unfortunately the returns for a lot of responses to a pandemic are a lot higher for coherent responses than varied ones. Half the countries wiping out Covid while the other half do nothing is far less than half as useful as everyone wiping it out. Its a large scale game of prisoner's dilemma.

It is a bit like prisoners dilemma, except that it's not clear what the best cooperate response is. I do agree though, that vastly differing responses are the worst outcome for those that do the most though.

Given the hit to our economy, I think opinions are deeply split here whether we made the right decision by shutting down for six weeks (even assuming it doesn't get reintroduced here.).

[Vinyadan]

Its a large scale game of prisoner's dilemma.

I personally like the psychotic version of the trolley dilemma, where you have already sent the trolley on the track littered with people and refuse to stop because it would be disrespectful towards those you have already run over.

[NichG]

It is a bit like prisoners dilemma, except that it's not clear what the best cooperate response is. I do agree though, that vastly differing responses are the worst outcome for those that do the most though.

Given the hit to our economy, I think opinions are deeply split here whether we made the right decision by shutting down for six weeks (even assuming it doesn't get reintroduced here.).

Its tricky to evaluate what would have been the best move from results in games like PD, because the best move locally depends on the moves others make, and following that local optimization finds the globally worst state.

So e.g. If everyone but 1/2 of all essential workers were in 100% isolation for 1 month, then the next month that 1/2 that worked went into 100% isolation for 1 month, then we could drive Covid (and influenza) extinct with just a month and a half ish shutdown.

But, even if we could do that, since there's no way to get the world as a whole to do it in sync... Even if every country agreed to do it, individuals might violate quarantine or might not comply with the process. And if a cluster survives, you basically have to do it all over again eventually. So we end up being stuck at the suboptimal equilibrium of the game. And looking back, one would say 'even the countries that did this are still importing new cases, so clearly it didn't do them any good'. But that's local reasoning, which can't find the optimum strategy in PD.

So I don't think it's that we don't know what a successful cooperation strategy would look like or what it might cost, rather that it's actually quite difficult in practice to get humans to cooperate to implement the strategies that would reliably and relatively cheaply solve the problem.

[Liquor Box]

Its tricky to evaluate what would have been the best move from results in games like PD, because the best move locally depends on the moves others make, and following that local optimization finds the globally worst state.

So e.g. If everyone but 1/2 of all essential workers were in 100% isolation for 1 month, then the next month that 1/2 that worked went into 100% isolation for 1 month, then we could drive Covid (and influenza) extinct with just a month and a half ish shutdown.

But, even if we could do that, since there's no way to get the world as a whole to do it in sync... Even if every country agreed to do it, individuals might violate quarantine or might not comply with the process. And if a cluster survives, you basically have to do it all over again eventually. So we end up being stuck at the suboptimal equilibrium of the game. And looking back, one would say 'even the countries that did this are still importing new cases, so clearly it didn't do them any good'. But that's local reasoning, which can't find the optimum strategy in PD.

So I don't think it's that we don't know what a successful cooperation strategy would look like or what it might cost, rather that it's actually quite difficult in practice to get humans to cooperate to implement the strategies that would reliably and relatively cheaply solve the problem.

I agree with most of that.

My only real disagreement is that I don't think it's clear that the strategy you outline is a good co-operation strategy, because taking that course destroys the economy (much moreso than taking a lighter touch I think). Eradication of the virus is not the only metric worth considering.

[NotASpiderSwarm]

What is "the economy"? Why is it good?

[Liquor Box]

What is "the economy"? Why is it good?

In the context I am talking about it (assuming that your comment was aimed at my reference), the economy is the production, trade and consumption of goods and services (from food to luxuries to housing to entertainment to insurance). All these things have been reduced by Covid, and by lockdown responses in particular.

It's good because without it we don't have the things we desire or need.

In real terms I expect the people will be most effected in first world economies are those who lose their jobs or businesses. This has the obvious implications of those persons not being able to support themselves or their families. Our country has a range of estimates for how many people will fall below the poverty line due to Covid based on how long the lockdown extends.

For those who keep their jobs, the effects may be less direct, but will still be there - lots of goods will be more expensive (due to reduced trade) provision of government services is likely to be reduced (because governments have incurred debt and are making less tax revenue), profits will be lower for businesses etc.

I'm not sure how third world or developing economies will be effected, but I'd guess that it will be even more severely.

[Kaptin Keen]

So e.g. If everyone but 1/2 of all essential workers were in 100% isolation for 1 month, then the next month that 1/2 that worked went into 100% isolation for 1 month, then we could drive Covid (and influenza) extinct with just a month and a half ish shutdown.

That would never work.

Let me give you an example. There is a retirement home here in Copenhagen which had a tragic spree of Covid-19 deaths. 16 people died.

When all staff was tested, 15 were positive - none had any symptoms. Like, zero out of fifteen showed any signs of being infected.

That guy who's bringing you the groceries you bought online? The clerk at the pharmacy? People working in transportation, packing, warehousing, agriculture - all those essential workers - they'll have it, some of them, and they'll be enough of a pocket for the virus to exist in.

No - we will all get it, eventually. It's a question of when, not if.

[Bavarian itP]

That would never work.

Let me give you an example. There is a retirement home here in Copenhagen which had a tragic spree of Covid-19 deaths. 16 people died.

When all staff was tested, 15 were positive - none had any symptoms. Like, zero out of fifteen showed any signs of being infected.

That guy who's bringing you the groceries you bought online? The clerk at the pharmacy? People working in transportation, packing, warehousing, agriculture - all those essential workers - they'll have it, some of them, and they'll be enough of a pocket for the virus to exist in.

No - we will all get it, eventually. It's a question of when, not if.

The staff of an retirement home where a lot of old people died were positive, so the guy bringing me groceries must be positive too? What?