The Maths of Coronavirus

[MarkS]

This Washington Post article has some interesting simulations that demonstrate the effectiveness of various strategies to reduce the number of people becoming ill simultaneously:

https://www.washingtonpost.com/graphics/2020/world/corona-simulator/

Mark

[Roberto]

Mark

This is behind a paywall and I'm not a reader of the WP but the paper from Imperial College that the UK government based its change on approach is available to everyone. It is relatively easy to follow and written in plain English:

https://www.imperial.ac.uk/media/imperial-college/medicine/sph/ide/gida-fellowships/Imperial-College-COVID19-NPI-modelling-16-03-2020.pdf

It's not comfortable reading but at least it describes what could be expected in quite a lot of detail.

Roberto

[Rick]

...and this analysis of pandemic limitation strategies was circulating on the Net at the end of last week:

https://link.medium.com/aNvjs2ctL4

Also not comfortable reading, especially as you go through it and spot all the occasions this country has done the wrong thing....

[NoelC]

Good articles thanks Roberto and Rick
The Imperial College one clearly defines the reasons for the Government's current strategy (and their sudden change of direction) detailing the risk of the second wave (quite rightly).  I couldn't see any consideration of virus loading; if you get a small amount of virus could your outcomes be dramatically different from if you are bombarded by virus 24/7?  I suspect there is a flaw in the argument, in that the PPE and Infection Prevention Controls for NHS staff appear inadequate (IMHO) and there will consequently be higher losses of staff from the hospitals (with an increased mortality risk associated). 

A hospital in Wuhan.

Front line nurses at a Coronavirus testing centre.
Spot the difference in PPE.

I think it's also worth noting the Case Fatality Ratio for different countries at present: 10% in Italy and 7% in Spain verses less than 0.5% in Germany and Austria.  We are at 5.2% and rising.  Obviously this reflects the difference in approach to testing and availability of tests, but it seems to reflect how overloaded systems are to cope with the virus.

[Rick]

The "Viral Load" thing seems to be trying to explain why London (in particular) is seeing a lot of patients in ICU who are relatively young (20s, 30s) and were fit and healthy before the virus got to them. According to the early evidence they should have been at low risk...

As a hypothesis, it makes some sense. Proof may take a while, but this virus is a killer, and I don't want to catch it, so I'll take any reasonable tips towards staying away from it.

The figures for London are certainly skewed by the lack of testing. If you only (mostly) count the cases that end up in hospital (who are more likely to be seriously infected) then your death rate is bound to be higher.

The Imperial College report may have been what finally tipped the government's ideas, but the numbers had been clear for at least a couple of weeks before that, while the clowns in number ten were still quipping about taking it on the chin and building herd immunity.

[Roberto]

Hopefully the experts can agree to disagree and in the end get us out of this mess:

https://www.bmj.com/content/bmj/368/bmj.m1216.full.pdf

Link to commentary on the recently (un)published paper by a team at Oxford University and their thesis that the spread may well be much larger than thought and that the R factor is in fact lower.

Roberto

[Rick]

A bunch of graphs... https://www.ft.com/coronavirus-latest

[NoelC]

Interesting about the Oxford Study; it's almost as if someone wanted them to produce a scientific study that says we don't need to bother too much...   Who on earth would have an interest in an opinion like that.  Clearly not the PM since he uses only the 'best science' to guide him.

Having read the WHO report on the China epidemic; I cannot help but be impressed with the amount of preparation China had clearly given to prepare for an epidemic.  40,000 medics sent to Wuhan within a week, and millions of pieces of stockpiled PPE and testing kits sent from every prefecture to the epicentre, surface decontamination kit deployed within a week. 
In comparison, the NHS was over 95% occupancy, less than 2.5 critical care beds per 100,000 of population, testing capacity of less than 5 tests per hospital per day and PPE that was nowhere near the standard set by WHO - a health care system that was in crisis before the crisis hit.

[Roy]

What is apparent from having read much of the called 'science' surrounding the Covid-19 epidemic is the extent to which these papers/reports are really speculation based on mathematical modelling which in turn relies on assumptions. We are currently hamstrung by a absence of hard data as a result of (1) insufficient testing for the virus (ideally should be in the millions by now within the UK) and (2) the lack of any test to identify those who have had the virus and have recovered. I for one am looking forward for a prick in the arm, because until we are all in inoculated, we cannot start getting back to some kind of normality. So let us hope that the development of a vaccine takes just a few months rather than the year to 18 months that has been predicted.

Roy

[Carole]

So let us hope that the development of a vaccine takes just a few months rather than the year to 18 months that has been predicted.

Ditto

[NoelC]

I think there's huge pressure to fast track a vaccine.  But fast tracking didn't work so well for the virus test the US CDC put together in Feb.  They have got vaccine test candidates now, but I guess there are huge risks involved if they get it wrong. We should keep in mind this will not be the last epidemic; I think we need to put more investment into the process we use rather than relying on a silver bullet to fix it (look at Germany). 

The test data that is being released at present seems weak.  The confirmed infections are really only an impression of admission rates, and the downturn may be a reflection of capacity as much as of infection rates. The rate of increase in mortality has slowed significantly, which is far too soon for the restrictions to have had that effect, maybe it indicates some other issue.  Have the NHS managed to improve management and outcomes, or is there some other systematic problem (like delays in the data)?

Number of cases (blue) and number of deaths (red) on a logarithmic scale (US dates).

I can't see why we aren't testing more.  Did you hear Radio 4 Any Answers this week? Prof Julian Peto of LSHTM suggested we could test at up to 10 million tests a day!  I like Trump's wartime powers act; I think something like that could be very useful here to sort some of the problems. 
[edited to update the url - someone blocked the old one]

[Carole]

Quinine is emerging as a treatment for coronavirus once you get it, and they are planning for possible use with hydrochloroquine (an ante malarial drug).  Still to be clinically proven.

It appears that tonic water has low doses of quinine in it so might be a good idea to have some on standby.

Carole

[The Thing]

G&T solves a lot of problems in the short term...

[RobertM]

Tonic water and Quinine - fact, fiction or just 'Fake News'...  at least the retailers will be guaranteed to sell out tomorrow.  There will also be a lot of people unaware of the medical consequences of taking too much.

Robert

[The Thing]

My understanding is its fake news. At least two people have died from overdosing on cholorquine in Nigeria hoping to protect themselves. I used to take it when I worked in Papua New Guinea in the 1980s, nasty hallucinations if you took two doses in a day by mistake. Nasty but necessary in that part of the world. 16 different mossies and 21 malarias :}