Corona Virus main thread

[BigFish 1,987]

4 minutes ago, Aggy said:

Am I right in thinking though that the R0 is based on number of contacts. It doesn’t determine how quickly it actually spreads (ie; how quickly those contacts take place). So in Sweden where the population density is something like 60 people per square mile it will spread a lot slower than the Uk where the population density is something like 720 people per square mile. 
 

So they might just think it’s going to be easier to manage over there whilst building that immunity up.

Well, yes and no. It is just statistics really. R0 is a measure of how quickly something is spreading. Increasing contacts will naturally increase R0, the speed of transmission. So the R0 is dependent on population density if contact frequency is.

Does that make sense?

[Mark .Y. 352]

1 hour ago, Aggy said:

I suppose there could be an argument that some of the official figures might include people who died from other things but had coronavirus (died “with” rather than “from”)? If so if you took the ONS suspected cases into account and removed some of the “died with” numbers they might balance out? 

Best info I could find on that kind of thing is this guy from Italy :

[BigFish 1,987]

4 minutes ago, Barbe bleu said:

R0 is a measure of how many people each carrier infects on average in a completely susceptible and freely mixing population. Its  not a rate.

To get the rate we need to also know how long we can infect for. 

HIV has a R0 of 10 in some popupations but that 10 are infected over the course of many years.

It does depend on circumstances though so I think that you are right Sweden could have a lower R0  if people just naturally mix less, so I guess this could be the thinking

 

 

@Barbe bleu puts it better than me!😀

[Aggy 755]

But presumably the rate/length of infection must be taken into account in calculating the R0.

If a virus is only infectious for, say, two days and you’re examining a population in some remote region in the arctic where people don’t see anyone other than immediate family more than once a week, then the r0 presumably becomes tiny because almost every time anyone gets it they have recovered (or died) before they see anybody else. 

I suppose this must be the case (in practice if not under a technical definition of r0) and explains why deaths in London and greater Manchester are greater than more remote areas. 

 

 

[Aggy 755]

23 minutes ago, BigFish said:

Well, yes and no. It is just statistics really. R0 is a measure of how quickly something is spreading. Increasing contacts will naturally increase R0, the speed of transmission. So the R0 is dependent on population density if contact frequency is.

Does that make sense?

Yep perfectly thanks.

[Aggy 755]

31 minutes ago, BigFish said:

Well, yes and no. It is just statistics really. R0 is a measure of how quickly something is spreading. Increasing contacts will naturally increase R0, the speed of transmission. So the R0 is dependent on population density if contact frequency is.

Does that make sense?

Although, presumably it’s a measure of how quickly something would spread if nobody was immune (rather than is actually spreading)?

See that’s where the confusion comes in for me at least - for instance I’ve just read an article suggesting in Italy some estimates reckon the r0 has gone to 0.8 as a result of the lockdown. But the 0.8 is still how many people would be infected if literally nobody was immune and were under the lockdown. The actual r would presumably be even lower than 0.8.

Edited April 30, 2020 by Aggy

[Yellow Fever 3,785]

I think you'll find R0 is really a theoretical number - never achieved or directly measurable in practice. In reality all we can attempt to measure is R ( < R0) for our society  / setup etc. R0 would be the 'natural' un-restricted spread of the virus assuming a bunch of lemmings (i.e. @ Cheltenham). And no - R or R0 isn't 'rate' but a dimensionless ratio.

My two-penneth anyway.

Edited April 30, 2020 by Yellow Fever

[T 190]

Yes that is the way BBC explains it. Ro is your natural spread without restrictions say at the start which is c.3. The R is the actual number people are currently infecting with restrictions say 0.8. As long as R is below 1 the number of new infections is going down becasue as you get better (or die) each person will infect less than one person. The graph in the BBC report on R is perhaps confusing as it is showing the cumulative number of cases whcih will still go up as long R is greater than 0 but the number of active cases will go down if R is below 1. Encourageingly both Germany and Denmark are reporting R is currently still below 1 with current gradual lifting of restrictions. S Korea even more encouraging that they have stopped local spread with restrictions and track, trace, isolate and now have limited restrictions showing you can get back close to normality in a few months. 

[ricardo 7,395]

In simplistic terms an R0 of 0.8 means that 100 people will have infected another 80 people. Over the next stage of the infection and if the R0 remains at 0.8 those 80 people will go on to infect a further 64 people and so on.

The number of infections only decline if the R0 remains below 1

[T 190]

Agreed, Good example though techncailly you jsut need to replace R0 with R as R0 is the theoretical unrestricted number and R is the current actual number with intervention. 

[ricardo 7,395]

Correct

[ricardo 7,395]

The daily report from the Robert Koch Institute (in English) is probably the most concise you will find anywhere.

https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus/Situationsberichte/2020-04-29-en.pdf?__blob=publicationFile

 

[Creative Midfielder 1,996]

7 hours ago, Van wink said:

This whole “following the science” is a convenient soundbite Badger but that really is all it is and I wouldn’t get too hung up about the phrase, the science, particularly in this pandemic is inexact and comes from a range of different potentially conflicting disciplines. 

It's definitely a convenient soundbite but its a big deal when the Prime Minister and other senior ministers who are supposed to be briefing us all (not fight an election campaign as you might suppose from the way they go about it!) about the state of the crisis, what the government is doing and how we are expected to behave and actually they are lying to try and cover for their own mistakes.

Ironic really that they were apparently concerned that the British might not follow initially the advice and then the legal requirements of the lockdown - seems to me that there was never any danger in this country that sensible scientific advice, never mind the legal aspects of the lockdown, wouldn't be followed by almost everyone bar an idiotic fringe. But that the advice and messages have come from the least trustworthy PM and Cabinet this country has ever had is certainly having an undermining effect on the message which appears to be ramping up as more and more mistakes (and broken promises) hove into view.

Think they have made a rod for their own backs and, again ironically, although they have very belatedly started to get their act together they still have a lot of very tricky decisions coming up and whichever way they jump now they are going to be met with a lot more skepticism going forward than would have been the case if they'd been more honest with us throughout - or made fewer mistakes early on or ideally both!!!

[Van wink 2,994]

1 minute ago, Creative Midfielder said:

It's definitely a convenient soundbite but its a big deal when the Prime Minister and other senior ministers who are supposed to be briefing us all (not fight an election campaign as you might suppose from the way they go about it!) about the state of the crisis, what the government is doing and how we are expected to behave and actually they are lying to try and cover for their own mistakes.

 

What are they lying about?

[The Real Buh 3,432]

The way in which statistics are being gathered and presented is vastly different between countries. Comparing data between countries is not scientific 

[ron obvious 1,502]

Anybody any idea why Spain's death rate is 5 times that of Portugal's?

[The Real Buh 3,432]

6 minutes ago, ron obvious said:

Anybody any idea why Spain's death rate is 5 times that of Portugal's?

There is blatantly a lot more to all of this.

why are some countries worse than others? Why has the western world been so disproportionately been affected? Big questions to answer.

[T 190]

25 minutes ago, ricardo said:

The daily report from the Robert Koch Institute (in English) is probably the most concise you will find anywhere.

https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus/Situationsberichte/2020-04-29-en.pdf?__blob=publicationFile

 

Careful some people of a sensitive dispostion may get upset to the German reference.  It is more of a technical report than a media report but the graphs of the cases declining substantial is encouraging. 

[Barbe bleu 826]

1 hour ago, Aggy said:

But presumably the rate/length of infection must be taken into account in calculating the R0.

If a virus is only infectious for, say, two days and you’re examining a population in some remote region in the arctic where people don’t see anyone other than immediate family more than once a week, then the r0 presumably becomes tiny because almost every time anyone gets it they have recovered (or died) before they see anybody else. 

I suppose this must be the case (in practice if not under a technical definition of r0) and explains why deaths in London and greater Manchester are greater than more remote areas. 

 

 

So R0 = the rate at which people are infected (the 'effective contact' rate ) x the average duration of the infectious period.

So yes you can work put R0 if you know the other values.

(Or, you could work out one of the other values if you know R0 and the other)

Example, I have a disease that infects on average 10 people a day and lasts 10 days then R0 = 10x10.  (Good luck managing that!) .

R0 is largely theoretical though as it relates only to the population mixing freely and assumes no one has the thing yet.  As soon as neither apply we need to talk about R or R(eff) or something similar and the 'force of infection' (ie then rate at which susceptible people come down with the lurgy)

R0 is relevant still though as this determines the level of immunity that we need to achieve together back to normal and see the thing still in decline.

This threshold is expressed as QC = 1- 1/R0.

If R0 = 3 then QC = 0.66. So at over 66% immune the thing will have no where to go and will slowly go.away (assuming we dont have children or immigration)

Edited April 30, 2020 by Barbe bleu

[Herman 9,765]

20 minutes ago, Van wink said:

What are they lying about?

Not sure if this is lying or just finagling the numbers to look better.

Not sure if this is lying or Michael Gove being Michael Gove.

 

[Ian 1,129]

22 minutes ago, The Real Buh said:

The way in which statistics are being gathered and presented is vastly different between countries. Comparing data between countries is not scientific 

Agreed, and it's obvious that this isn't anywhere near approaching an exact science, and it will take some time to get an accurate global picture of exactly what has happened.

Unfortunately, a lot of people have a specific narrative (one way or the other), which means the huge uncertainty gets lost or ignored.

[Creative Midfielder 1,996]

Just now, The Real Buh said:

There is blatantly a lot more to all of this.

why are some countries worse than others? Why has the western world been so disproportionately been affected? Big questions to answer.

Portugal v Spain is very straightforward.

Portugal locked down very early and tightly controlled its borders, and so far have come out it very well.

Spain (and others including the UK) didn't, and so far have done very badly.

[The Real Buh 3,432]

Just now, Ian said:

Agreed, and it's obvious that this isn't anywhere near approaching an exact science, and it will take some time to get an accurate global picture of exactly what has happened.

Unfortunately, a lot of people have a specific narrative (one way or the other), which means the huge uncertainty gets lost or ignored.

The amount of “hidden deaths” will be massive as well. Suicides etc and in developing countries I suspect asking people to not leave their houses for weeks on end will lead to starvation and all sorts of other disease risks. This is a pretty huge issue and the data is huge but we should focus on our data as I really think it’s accurate. I don’t trust politicians but I do trust our scientists and data gatherers/analysers.

[The Real Buh 3,432]

1 minute ago, Creative Midfielder said:

Portugal v Spain is very straightforward.

Portugal locked down very early and tightly controlled its borders, and so far have come out it very well.

Spain (and others including the UK) didn't, and so far have done very badly.

There’s no way it’s as simple as that. Lockdown and social distancing works well in containing the virus but it still doesn’t explain massive regional differences. I believe there are all sorts of social factors like population density and cultural “closeness” if you like but I believe there is a genetic link to this. I think certain genetic makeups are more susceptible to immune response which I believe is a common attribute virus’. It appears to be disproportionately hitting men over women for example. 

[Ian 1,129]

14 minutes ago, Creative Midfielder said:

Portugal v Spain is very straightforward.

Portugal locked down very early and tightly controlled its borders, and so far have come out it very well.

Spain (and others including the UK) didn't, and so far have done very badly.

Gross oversimplification.

[Creative Midfielder 1,996]

1 minute ago, The Real Buh said:

There’s no way it’s as simple as that. Lockdown and social distancing works well in containing the virus but it still doesn’t explain massive regional differences. I believe there are all sorts of social factors like population density and cultural “closeness” if you like but I believe there is a genetic link to this. I think certain genetic makeups are more susceptible to immune response which I believe is a common attribute virus’. It appears to be disproportionately hitting men over women for example. 

I think it is exactly that simple in that particular case - of course there are other factors as well, as you say men seem to be dying more than women and in this country anyway it seems that ethnic minorities are suffering disproportionally as well although I don't think there is any explanation yet as to why either of these generalisations might hold true.

But in Portugal and Spain you have two close neighbouring populations who are very similiar socially, culturally and I would guess genetically as well.

But they have had radically different outcomes to this crisis. So given that they also had radically different strategies for tackling the crisis that seems to me much a much better correlation than the idea that there is some other, as yet undiscovered factor, which could account for such an extreme disparity between two such similar countries.

[Creative Midfielder 1,996]

3 minutes ago, Ian said:

Gross oversimplification.

Really, so what's your explanation then - simple or complex take your pick, I'd love to hear it.

[The Real Buh 3,432]

2 minutes ago, Creative Midfielder said:

I think it is exactly that simple in that particular case - of course there are other factors as well, as you say men seem to be dying more than women and in this country anyway it seems that ethnic minorities are suffering disproportionally as well although I don't think there is any explanation yet as to why either of these generalisations might hold true.

But in Portugal and Spain you have two close neighbouring populations who are very similiar socially, culturally and I would guess genetically as well.

But they have had radically different outcomes to this crisis. So given that they also had radically different strategies for tackling the crisis that seems to me much a much better correlation than the idea that there is some other, as yet undiscovered factor, which could account for such an extreme disparity between two such similar countries.

There are definite differences between the two countries but even on individual cases some people are being massively disproportionately affected. It appears you get this virus and you roll the dice on how it will hit you. There are lots of questions to be answered but as far as raw data I would strongly caution against comparing it between countries, I would caution against even comparing data between the home countries, it’s not scientific. I believe we are being honest With our data and I believe some countries aren’t being honest and that will kick them in the a@&£ st some point. There is definitely, definitely something fishy about how this virus as spread and affected people though.

[Ian 1,129]

1 minute ago, Creative Midfielder said:

Really, so what's your explanation then - simple or complex take your pick, I'd love to hear it.

Simple answer is we do not know enough yet to make such a judgement, and I would certainly not have any confidence to make that statement.

If you are an expert in the area, by all means correct me, otherwise I expect you have an opinion or agenda that you are looking to validate. Like most media commentators who disrespectfully jump all over the "death comparison" charts without making any attempt to understand what they represent, and the limitations of them.

[The Real Buh 3,432]

https://www.edp24.co.uk/news/health/hms-qe-sets-sail-despite-positive-coronavirus-tests-1-6632216

 

The fact our primary aircraft carrier is rushing to sea trials even with coronavirus cases onboard tells you a lot about what might be just around the corner