Corona Virus
A series of write ups on the virus
Statistics
01/5/2020
The UK government announcements are focused on something
called the R value. This is a value which is difficult to
calculate, can be calculated in different ways.
I find it far easier and more intuitive in the case of the
Covid19 virus to simply use the growth value. Basically this is
How many today
-------------------- x 100%
How many yesterday
This figure jumps about all over the place, but
by smoothing it out, firstly by switching to a weekly number (as
the weekends always produce lower numbers, and then making a
seven day rolling average the graph becomes readable.. The graph below shows these figures
for the UK.

When the growth rate is above 100% the virus is spreading,
the higher the faster. When it is below 100% the number of cases
each day is decreasing. We can see from the graph above that we
passed the 100% point around 16th of April, and the rate is now
at 97.5%.
The lower the rate the faster the reduction in mortality.

The graph above shows how long we can expect the pandemic to
"last" is dependent on the growth rate. For example at
todays rate (1st May) of 97.5% it would take us about 170 days
to reach a mortality of under 10 deaths per day. In this
time we would see around another 26000
deaths
If want to achieve this faster then we need to reduce
the growth rate further. Is this possible?
China achieved a growth of around 93%. If we did that then
we would reach the under 10 death per day figure in about 60
days, and reduce the extra deaths to around 10,000. But
Wuhans lock down was brutal, and it was only one city with the
rest of China to support it.
Italy is currently running at 96%. If we can copy that
then our 10 deaths per day figure comes down to 106 days and we
deaths reduce by around 8-9000.
Lockdown
When will the government ease lockdown? They will probably want
to get the growth rate down lower than it is now, but easing of
lock down restrictions could case a rise in the growth rate,
possibly up to over 100% and the disease would start spreading
again.
Hopefully when the government can deliver PPE to the
hospitals and care homes we will see the growth drop further.
Currently death growth in care homes is around 104%, and the
deaths account for 40% of the UK total. Hospital only deaths
growth rate
We must also remember that 739 people died today, and the
mortality rate is 3.5% so about 25,000 people were infectious
around two weeks ago. Rates are not dropping fast, so
around 25,000 people are still infectious.
Update 2/5/2020
If we take Australia and New Zealand figures (both of whom do a
proper job of testing) then the mortality rate is only 1.36%
this means that, in the UK around 54,000 people are
still infectious.
300 people have died in care homes. Now mortality
is much higher in the elderly, maybe 10%. So around 3000 people
were infected about 2 weeks ago. There are more now.
UK hospital deaths show a growth rate of just under 96% which is
much better than the 97.5 for the whole of the UK. The
difference is due to the care homes.
I have saved the results from before the UK changed the figures to
include care home deaths.
The government are not providing graphs on care home deaths, so
here they are:-

The negative values are probably due to data errors in the care
home data, but the 7 day average (the black line) shows an
obvious positive slope showing that the death rate is
increasing. Almost certainly due to lack of PPE.
Update 04/05/2020
On a very macabre note the latest statistics from the government
show 315 new deaths overall and 369 in hospital for May 2nd.
This implies that the care homes are helping the figures by
having 81 resurrections!
I think its an admin error and the figures are reversed so the
actual deaths are higher than published.

Screen shot from
government stats.
Grant Shapps in now admitting that there would have been few
deaths if the UK had a greater testing capacity.
Italy locked down on 9th March with 463 deaths.
Spain locked down on 14th March with 196 deaths. They did
not learn from Italy.
The UK locked down on 23rd March with 359 deaths. Our government
did not learn from anywhere.
Had we locked down around the same time as Italy we could have
been in a similar position to New Zealand or Australia with
total deaths in the low hundreds. Instead Total deaths
will be around 40,000.
|