Update on post-plateau cases

Please see below the latest post-plateau comparison of new cases in selected markets. This uses the same methodology as my previous posts on the subject where the rate of new cases is indexed to 100% at the average peak value in each country. A few countries have the data shunted forward a day or two in order to make the patterns clearer. 

We still have the same underlying patterns appearing - countries with lower rates of infection seem to have declined faster, with those with a higher rates appear to be declining more slowly (although this may also be connected with the different strains of Covid-19 in circulation). This shape would be consistent with the 'fireman's helmet' shape that has been mentioned by the UK government - a rapid increase (classic exponential), a flat spot and then a slow decline in new cases.

If the UK is to follow the shape of the latter group then we are looking at a 40% decrease in new cases at 10 days after the peak, with hopefully a further drop of 20% of the original peak in the following ten days. The question still remains though, why hasn't the UK started to decline?

One factor we need to consider here is the level of new cases among key workers - this has become a sizeable component of new cases in the last week or so, and these pillar 2 cases as they are known appear to be offsetting any reduction in the level of new cases in the general population.

Here is the COBR slide from yesterday:

Looking at the stacked bar format it would appear to be a fairly consistent top-line number (both bars added together), with a hint of improvement in the last two days, although it's probably too early to tell. What is striking is the amount of new cases in pillar 2 in the last week, on April 20th this accounted for 35% of new cases and 20% of all new cases in the last 7 days. This additional source of new cases is definitely contributing to the delay of the decline of new cases. If we split the two pillars out (see below) you can start to see the early suggestions of a decline in the UK in pillar 1 (top chart) whilst the trends in pillar 2 is quite concerning - hopefully this contains some milder cases picked up earlier in the disease lifecycle and can be brought quickly under control. 

I am watching both these daily figures with interest.

I would like to point out that I am definitely not trying to assign any blame key workers at this point - by definition the are key workers that have to put themselves at higher risk of infection to do their jobs and save lives. They have my admiration.