Re: SARS-CoV-2 testing
Posted: Thu Aug 06, 2020 11:19 am
Kings College Covid-19 app estimates 2110 new cases per day.
https://covid.joinzoe.com/data#daily-ne ... source=App
https://covid.joinzoe.com/data#daily-ne ... source=App
Interesting the way that footfall seems to have plateaued even though spending continues to increase.lpm wrote: ↑Thu Aug 06, 2020 8:28 amIt would be rational for young people to go to pubs - very low risk - but fewer 50 year olds. Social get-togethers are group decisions, so six 20 year old friends might agree to meet up in a pub, but in a group of six 50 year olds two might veto the decision so the entire group goes to a garden BBQ instead.
John Burn-Murdoch has the charts of activity:
https://twitter.com/jburnmurdoch/status ... 1873455110
It would be very useful to see something like this split by age grouping. Anecdotally, it's young people out and about.
Economic factors are also relevant. With the end of the furlough scheme and job losses, millions won't be able to afford shopping and restaurants and pubs. This might shift the mix.
Round my way some places have compensated for reduced capacity/footfall by increasing prices.
Well I plotted the number of swabs and the number of cases per day on axes such that we can see whether cases are really going up because of increased testing. (The lines are 7-day moving averages to smooth out the weekly variation).shpalman wrote: ↑Thu Aug 06, 2020 9:12 amFine, the number of cases in the UK isn't increasing. It was always that high but testing was sh.t. Well, it's still sh.t, but getting a bit less sh.t than before. There's no clear idea now of how many swabs have been performed, and the number of people tested was lost track of ages ago. And there's no record of how many people have recovered.
And the UK is still on over 800 cases per day and currently about 400 deaths per week (compared to an ONS death rate of about 8000-9000 per week at this time of year, so maybe 4-5% of all deaths). If you take that death rate and assume an IFR of 2.5-3.5% as the Italian antibody study suggests, you're looking at the order of 2000 cases per day (yeah I know that number applies to two weeks ago or whatever but unless deaths go down significantly in the next two weeks, it's valid now).
Because comparisons with other countries are meaningless,* Italy has a covid-positive death rate of about 50 per week at the moment. (Italy is testing 27,000 cases per day, performing 50,000 swabs, and the fraction of people tested who turn out to be positive is about 1.1% at the moment. Cases per day is going up in Italy because of a few localized outbreaks, for example in Mantova (Lombardy was actually stable at about 60 cases per day until that happened; the nearby regions of Veneto and Emilia-Romagna are increasing but from much lower baselines).
* - Weird how the UK decided comparisons with other nations were meaningless at the point at which it started to obviously do worse than other nations.
Probably because the gov.uk page has completely changed. Again. (This one: https://coronavirus.data.gov.uk/cases)
Prevalence as high as 58% would argue against the modeling which suggested that herd immunity could be achieved with as low as 20% infected.Results: The positive test rate was 54.1% (95% CI: 52.7 to 55.6) and 16.1% (95% CI: 14.9 to 17.4) in slums and non-slums, respectively, a difference of 38 percentage points (P < 0.001). Accounting for imperfect accuracy of tests (e.g., sensitivity, 0.90; specificity 1.00), seroprevalence was as high as 58.4% (95% CI: 56.8 to 59.9) and 17.3% (95% CI: 16 to 18.7) in slums and non-slums, respectively.
Conclusions: The high seroprevalence in slums implies a moderate infection fatality rate. The stark difference in seroprevalence across slums and non-slums has implications for the efficacy of social distancing, the level of herd immunity, and equity. It underlines the importance of geographic specificity and urban structure in modeling SARS-CoV-2.
Or it could be evidence that if you don't have a strong immune system then living in a slum will have killed you long before Covid-19 came along to try.Woodchopper wrote: ↑Tue Sep 01, 2020 10:02 pmThe low IFR could be more evidence that people whose immune systems encounter a lot of infections are much better able to fight off Covid without getting very ill. Or maybe the slum dwellers are all young.
Yes, that too.Millennie Al wrote: ↑Thu Sep 03, 2020 3:15 amOr it could be evidence that if you don't have a strong immune system then living in a slum will have killed you long before Covid-19 came along to try.Woodchopper wrote: ↑Tue Sep 01, 2020 10:02 pmThe low IFR could be more evidence that people whose immune systems encounter a lot of infections are much better able to fight off Covid without getting very ill. Or maybe the slum dwellers are all young.
Slum residents are less likely to be obese or diabetic?Woodchopper wrote: ↑Thu Sep 03, 2020 3:18 amYes, that too.Millennie Al wrote: ↑Thu Sep 03, 2020 3:15 amOr it could be evidence that if you don't have a strong immune system then living in a slum will have killed you long before Covid-19 came along to try.Woodchopper wrote: ↑Tue Sep 01, 2020 10:02 pmThe low IFR could be more evidence that people whose immune systems encounter a lot of infections are much better able to fight off Covid without getting very ill. Or maybe the slum dwellers are all young.
That's likely. Though I wouldn't go as far as saying that slums in India or Africa have fewer people with co-morbidity. They are pretty unhealthy places, but as Millennia Al suggests, maybe sick people die before they get old.AMS wrote: ↑Thu Sep 03, 2020 6:31 amSlum residents are less likely to be obese or diabetic?Woodchopper wrote: ↑Thu Sep 03, 2020 3:18 amYes, that too.Millennie Al wrote: ↑Thu Sep 03, 2020 3:15 am
Or it could be evidence that if you don't have a strong immune system then living in a slum will have killed you long before Covid-19 came along to try.
That seems quite a reasonable hypothesis, and I'm not sure there's much in your link that undermines it - especially if it's a particular coronavirus lineage endemic to Africa that contributes to immunity.
I have no idea, they don't give you that option unless you start again. I have now managed to order one, maybe they were overloaded with requests earlier. It's supposed to come within 48 hours but as that will be Sunday, it will be longer than that and then I have to book a courier to return it. So it could be a lengthy process.lpm wrote: ↑Fri Sep 04, 2020 11:17 amYep, they increased quantity at the expense of quality, then redirected capacity to the hotspots up north.
The stats for the south east and south west are so low they probably decided it's not worth bothering with much testing. But London is higher and seems to be rising.
Out of interest, what is the nearest test centre you could get to in a car?
This is just so weird to me. Most people here get their results in under 24 hours - you just turn up, take a test and then they call you back. If you get tested in the morning you'll often hear by the end of the day.Tessa K wrote: ↑Fri Sep 04, 2020 11:46 amI have no idea, they don't give you that option unless you start again. I have now managed to order one, maybe they were overloaded with requests earlier. It's supposed to come within 48 hours but as that will be Sunday, it will be longer than that and then I have to book a courier to return it. So it could be a lengthy process.lpm wrote: ↑Fri Sep 04, 2020 11:17 amYep, they increased quantity at the expense of quality, then redirected capacity to the hotspots up north.
The stats for the south east and south west are so low they probably decided it's not worth bothering with much testing. But London is higher and seems to be rising.
Out of interest, what is the nearest test centre you could get to in a car?