Now they say 17% have had the Virus

Longer than you think. If you are talking about tourism apart from China, Australians are the single biggest tourist in NZ and they will be welcoming them. As for Chinese tourists I think that problem will not be exclusive to NZ or Australia for years to come.
"As for Chinese tourists I think that problem will not be exclusive to NZ or Australia for years to come."
Not too sure what you mean by that?
 
Ref Herd immunity - 30% was enough to halt the spread of Spanish flu in 1918/19 so to me 17% is significant. Notice there were no hospital CV19 admissions in London on one day earlier this week, in a population of nearly 9m people despite lock down measures coming off and more people returning to work.

I also don't believe it can be 17% in London and 5% elsewhere, my guess is the else where is higher than 5%. Look at South Tees - 230 deaths? multiplied by 250 for infections = 57500 in a catchment area of 350000? = approximately 16.4% have been infected.

On BBC News Channel - The Swedish virus expert thought Sweden had 10% infection rate and they are 2 weeks behind us. He also was adamant that you can't catch CV19 twice. He said herd immunity was a key way to get rid of the virus.

What we have learnt? - CV19 spreads extremely easily, much more easily than many other viruses, but its not as fatal (say around 1 in 250 effected) as many serious viruses.

For approximately 50% of people there are no symptoms and only small symptoms for many of the rest. Evidence Watford player saying he was perfectly fine and had been rarely out of the house, but he tested positive. Earlier this week another 5 people in Premiership clubs tested positive without showing any obvious signs. Because it is invisible for many it spreads more easily as the infected often don't realise they are spreading it.

Maybe the way to proceeed his herd immunity for the majority of the population, but lock down for high risk groups until there is a vaccine.

Welcome to team hope and reality. We are a forever growing team who had a rocky start to life in league BUT have been growing in confidence and knowledge with hopes of winning the title by season's end. 😉
 
So sad and I am so angry what happened with these CV19 ambulances taking infected old people into care homes. I am sure most of the hospital staff were acting in good faith and doing what they were told, but without a negative test result the old person should never have left the hospital and the care home should have bolted their doors. The testing facilities were inadequate to say the least in March and early April. I don't know where the problem was, but it was pointed out on here Germany was doing 100,000 tests per day in late March and we were doing 4,000? and then taking up to 8 days to get a result.

Some experts on SAGE said CV19 was rampant in the UK on Feb 12th, but their opinions (evidence by lack of PHE and UK Government action) were pretty much ignored.
 
My thoughts have never changed about the nature of the Virus. Very quick spreader, low fatality (for healthy under 65s), mainly invisible unlike say common flu.

Solutions are more tricky by allowing unrestricted herd immunity if say we take 100,000 relatively quick deaths to keep 66m million, but in a modern society that is psychologically difficult, so many Government have said shut down hoping for a quick vaccine and to allow their healthcare systems to cope better with infections that are spread out.

Our tracking systems collapsed about March 12th.

A lot of the NHS PPE stock was out of date.

We had small capacity in hospitals and low number of ventilators compared with many of other developed countries

Our testing facilities were relatively tiny for a long time and the systems were slow, possibly because everything was so centralised

We didn't restrict movement enough of elderly people into care homes from hospitals.

The dominant UK experts for some reason denied the real infection rates and rejected herd immunity (for healthy under 65s)

The only real success seems to be putting up Nightingale hospitals quickly.

Although the virus was no ones fault in this country the reactions feels like the Soviet Union dealing with Chernobyl with lots of local heroes at the coal face led by semi - incompetents.

Am I being too harsh?
 
I notice today the experts are saying 17% of people in London have had the Virus - quite a jump from 10% a few days ago - this time they think the figures are more accurate, but could be 4 weeks out of date, so it will be higher by now.

The rest of the country is officially 5% but will catch up to the London figure with time, so in say 2 weeks time will be 17% too.

I have been posting for over a month that the 4% figure infection rate was wrong, based on number of UK CV19 deaths and quoted fatality rate, say approx. 50,000 deaths (remember some CV deaths are not officially recorded) multiplied by 250 fatality rate (0.004) = 12.5m infections = 19% of the UK population.

So here's today's maths lesson:

Firstly, the population of London is approx. 9.3m with the population of the rest of England (as these estimates relate to England not the UK) being approx. 45.7m. If 17% of people in London and 5% elsewhere in England have already had the disease, that equates to a total of approx. 3.9m people in the whole of England.

There are 55m people who live in England. For 17% of that population to have been infected would mean a total of 9.4m people. Subtracting the 3.9m who are estimated to have already been infected gives us a balance of 5.5m people.

The current infection rate (according to ONS analysis) is 0.25% of the population, which equates to 137,000 in England. To reach your statement that 17% of all people in England will have had the disease in 2 weeks' time, would require those 137,000 to infect (directly or indirectly) 5.5m people within a fortnight.

If we are generous and assume that the infectious period for Covid-19 is just 7 days (the shorter the infectious period the lower the R number), then the R number would be the square root of 5.5m/137k which equals 6.3.

I don't think anyone has ever suggested it being as high as that and, if it was, a far higher number of the population than 3.9m would have already had the virus. I'm afraid I'm going to file this alongside the claim that "we'll all have had it by the end of May" that I read on here a couple of weeks ago.
 
Doesn't make much of a difference if you can catch it twice though

Korean studies have stated that all "reinfections" reported so far were false negatives. They also did a study on those that had a positive after a negative. There were 400 odd of these, they found 3 new infections, all of which were traced back to that loopy church, rather than from the people who tested positive again. So in the short term it looks like there is resistance at least.
 
Ref Herd immunity - 30% was enough to halt the spread of Spanish flu in 1918/19 so to me 17% is significant. Notice there were no hospital CV19 admissions in London on one day earlier this week, in a population of nearly 9m people despite lock down measures coming off and more people returning to work.

I also don't believe it can be 17% in London and 5% elsewhere, my guess is the else where is higher than 5%. Look at South Tees - 230 deaths? multiplied by 250 for infections = 57500 in a catchment area of 350000? = approximately 16.4% have been infected.

On BBC News Channel - The Swedish virus expert thought Sweden had 10% infection rate and they are 2 weeks behind us. He also was adamant that you can't catch CV19 twice. He said herd immunity was a key way to get rid of the virus.

What we have learnt? - CV19 spreads extremely easily, much more easily than many other viruses, but its not as fatal (say around 1 in 250 effected) as many serious viruses.

For approximately 50% of people there are no symptoms and only small symptoms for many of the rest. Evidence Watford player saying he was perfectly fine and had been rarely out of the house, but he tested positive. Earlier this week another 5 people in Premiership clubs tested positive without showing any obvious signs. Because it is invisible for many it spreads more easily as the infected often don't realise they are spreading it.

Maybe the way to proceeed his herd immunity for the majority of the population, but lock down for high risk groups until there is a vaccine.
I’m finding it increasingly hard to accept the figures we are being given. It makes no sense to me that London figures, at this stage of the lockdown, should be any better or any worse or any different to other built up areas of the country. The figures should be the same within a small percentage.
 
I also don't believe it can be 17% in London and 5% elsewhere, my guess is the else where is higher than 5%. Look at South Tees - 230 deaths? multiplied by 250 for infections = 57500 in a catchment area of 350000? = approximately 16.4% have been infected.

But your assumption for the Infection Fatality Rate is 0.4%, which is slightly on the low side. A systematic review of 13 different studies published this week estimates the IFR at 0.75%.

Also, the South Tees NHS Trust serves the population of Middlesbrough, Redcar & Cleveland, Hambleton and Richmondshire. That's a total population of approx. 420,000 people.

If we apply those numbers to your calculations, you get:

230 divided by 0.75% = 30,667 in a catchment of 420,000 = approximately 7.3% have been infected.

I’m finding it increasingly hard to accept the figures we are being given. It makes no sense to me that London figures, at this stage of the lockdown, should be any better or any worse or any different to other built up areas of the country. The figures should be the same within a small percentage.

I would probably put this down to London and the rest of the country being in different stages of the epidemic at the point the lockdown was imposed. It's generally accepted that London was ahead of the rest of the UK at that point, so the virus would have had longer to circulate around the capital's population before social distancing was introduced in order to surpress it.
 
So here's today's maths lesson:

Firstly, the population of London is approx. 9.3m with the population of the rest of England (as these estimates relate to England not the UK) being approx. 45.7m. If 17% of people in London and 5% elsewhere in England have already had the disease, that equates to a total of approx. 3.9m people in the whole of England.

There are 55m people who live in England. For 17% of that population to have been infected would mean a total of 9.4m people. Subtracting the 3.9m who are estimated to have already been infected gives us a balance of 5.5m people.

The current infection rate (according to ONS analysis) is 0.25% of the population, which equates to 137,000 in England. To reach your statement that 17% of all people in England will have had the disease in 2 weeks' time, would require those 137,000 to infect (directly or indirectly) 5.5m people within a fortnight.

If we are generous and assume that the infectious period for Covid-19 is just 7 days (the shorter the infectious period the lower the R number), then the R number would be the square root of 5.5m/137k which equals 6.3.

I don't think anyone has ever suggested it being as high as that and, if it was, a far higher number of the population than 3.9m would have already had the virus. I'm afraid I'm going to file this alongside the claim that "we'll all have had it by the end of May" that I read on here a couple of weeks ago.

Yourstatistical expertise may be good, but I'm not so sure about your reading and comprehension.
 
But your assumption for the Infection Fatality Rate is 0.4%, which is slightly on the low side. A systematic review of 13 different studies published this week estimates the IFR at 0.75%.

Also, the South Tees NHS Trust serves the population of Middlesbrough, Redcar & Cleveland, Hambleton and Richmondshire. That's a total population of approx. 420,000 people.

If we apply those numbers to your calculations, you get:

230 divided by 0.75% = 30,667 in a catchment of 420,000 = approximately 7.3% have been infected.



I would probably put this down to London and the rest of the country being in different stages of the epidemic at the point the lockdown was imposed. It's generally accepted that London was ahead of the rest of the UK at that point, so the virus would have had longer to circulate around the capital's population before social distancing was introduced in order to surpress it.

They can't work out an IFR if they don't know how many people have been infected. And by that I mean you have to take into account the presently unknown asymptomatic patients, children and young people. There is a complete disconnect between the figures derived from tests and the reality that most people are experiencing. For instance, if the randomised Stockholm test results from end of April give 7.5% of people with antibodies ... which take 3 to 4 weeks to show, then in early April there were 150,000 people infected in Stockholm. Roughly. The current cumulative total for positive tests in the whole of Sweden is less than 33,000. I wouldn't know how many people those 150,000 people were capable of infecting in the ensuing 6 to 8 weeks, but, one would have to imagine it's a lot.

Statistical analysis requires good data and it would seem that the data coming from testing is way behind what is happening in reality.
 
But your assumption for the Infection Fatality Rate is 0.4%, which is slightly on the low side. A systematic review of 13 different studies published this week estimates the IFR at 0.75%.

Also, the South Tees NHS Trust serves the population of Middlesbrough, Redcar & Cleveland, Hambleton and Richmondshire. That's a total population of approx. 420,000 people.

If we apply those numbers to your calculations, you get:

230 divided by 0.75% = 30,667 in a catchment of 420,000 = approximately 7.3% have been infected.



I would probably put this down to London and the rest of the country being in different stages of the epidemic at the point the lockdown was imposed. It's generally accepted that London was ahead of the rest of the UK at that point, so the virus would have had longer to circulate around the capital's population before social distancing was introduced in order to surpress it.
Appreciate that but if you look at the north east the infection rate in places like Middlesbrough, Gateshead, South Tyneside and Sunderland are up at the top for the country. This would indicate to me that we have caught up and gone past London and locked down or not families live together, essential workers work together, people shop in Asda etc etc, there are plenty of ways the virus can spread. If the infection rates were much lower than London then I would agree but there is an anomaly in my view between the herd immunity figures and the infection rates.
 
They can't work out an IFR if they don't know how many people have been infected. And by that I mean you have to take into account the presently unknown asymptomatic patients, children and young people. There is a complete disconnect between the figures derived from tests and the reality that most people are experiencing. For instance, if the randomised Stockholm test results from end of April give 7.5% of people with antibodies ... which take 3 to 4 weeks to show, then in early April there were 150,000 people infected in Stockholm. Roughly. The current cumulative total for positive tests in the whole of Sweden is less than 33,000. I wouldn't know how many people those 150,000 people were capable of infecting in the ensuing 6 to 8 weeks, but, one would have to imagine it's a lot.

Statistical analysis requires good data and it would seem that the data coming from testing is way behind what is happening in reality.

I agree (sort of). Mathematical modelling should be used/relied upon in the absence of robust data, it's not a replacement for it.

I wouldn't have used Redwurzel's method for calculating the infection level locally, I was merely showing what happens if you use a different set of assumptions (including the correct population figures).

But we don't need to undertake such modelling, as we have the results from several weeks' antibody testing. Those show that 17% of the London population and 5% of the rest of the country have so far been infected.
 
I agree (sort of). Mathematical modelling should be used/relied upon in the absence of robust data, it's not a replacement for it.

I wouldn't have used Redwurzel's method for calculating the infection level locally, I was merely showing what happens if you use a different set of assumptions (including the correct population figures).

But we don't need to undertake such modelling, as we have the results from several weeks' antibody testing. Those show that 17% of the London population and 5% of the rest of the country have so far been infected.

I think that the words "at least" should figure in your last statement given that the tests are known to miss some people who have tested positive for active virus, and also those who have dealt with the virus via their innate immune system.... which could be quite a significant number (especially as that includes kids, young people etc ... a significant portion of London's population). The other elephant in that particular room is the number of people who have died or are still in intensive care, who will not form part of the sampling group).
 
There is a link to the latest work on IFR by John Ioannidis of Stanford University in this article by Ross Clark.

Stanford Study

Sorry Billy that you won't be able to read it as the article is in the Spectator
 
BH - thanks you for your analysis and stats - I guessed the South Tees figure I didn't realise all of Hambleton and Richmondshire areas were included so thanks for your figure.

Ref Fatality rate

Looking at the Diamond Princess which contained 3711 passengers (see link below). The Cruiser was marooned at sea for a long period and most passengers would have been exposed to the virus and all were tested. The cruiser gives a good picture of the virus at work in detail in an enclosed area with a large sample size. Of those 3711 passengers, 705 caught the virus. Of these 705, only 6 died (all over 70). This gives 0.85% fatality rate however most of the passenger we would expect to be 60 or over or certainly well above average age range and not many child/young adult passengers . This would have increased the fatality rate for the Diamond Princess relative to say a profile of the South Tees hence 0.85% is not normal for a UK NHS Trust area. The 0.75% IFR figure looks too high based on this.

https://www.dailymail.co.uk/news/ar...onavirus-isnt-deadly-feared-death-rate-1.html

There seems to be a trend of over estimating the fatality rate - possibly because people naturally look at the last pandemic (Spanish Flu) whose fatality was higher and in a lock down experts want to be seen as looking at the worst case options. Also many people catch the virus without knowing so infection numbers can easily be underestimated which has the effect of increasing fatality rate. i.e. 1 death out of 5 infections = 20% but 1 out of 8 = 12.5%

The other interesting thing about the Diamond Princess figures is that 81% of the passenger avoided the virus which suggests there is significant natural immunity - possibly in the range of 30% to 50% (I assume at least 50% of the passengers had some exposure as they had to go for meals and toiletries etc and if someone was infected they could not be isolated). This backs up Alves point of a decent natural immunity rate.

So the virus spreads very quickly but amongst a select population profile, of those profile approx. 50% don't realise they have had it .

The virus is dangerous to the over 70s (and select illnesses), but much less so to anyone else.

Ref: the quoted 5% and 17% infection figures - I don't believe the 5% figure for outside London and don't believe 2 weeks would close the gap. I didn't make it clear in my post which is my fault. Billy Horner makes it 7.3% infection for South Tees and I think he is on the conservative side - that is quite different from 5% Government figure.
 
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