Follow the Numbers

Day after day, figures regarding the infection are going only one way and it's up. More than 300 thousands with over 13000 deaths.

Taking into account what I was mentioning in a previous post, which has been now widely admitted by world leaders, i.e. that these official figures are only the tip of the iceberg, we are certainly beyond 5M infected worldwide

And yet, I think it is worth looking beyond the cold cruelty of these massive numbers.

Two weeks ago, I started to follow some trends on my own excel chart. Beyond the great reports you can find online, the idea was to see if I could guess a pattern while looking at the ratios in the evolution of the figures, instead of merely following the global counting.

And then I soon realised that some had done it before. Including Nobel prize winner Michael Levitt, who looked into the figures that out of compassion for his Chinese friends as he is married to a Chinese lady https://www.calcalistech.com/ctech/articles/0,7340,L-3800632,00.html . So at least, even if you don’t want to take my word for it, you can still refer to this article.

In short, what can we see from the relative figures that the absolute numbers are not showing?

Here are a few findings:

-       after the initial incubation period when figures are very low, comes the outbreak. At that stage, figures are generally growing by 30% / day, so doubling every 3 1/3 days.

-       generally, after two weeks, the main voluntary self-isolation measures are put in place. In absolute numbers, the figures have been skyrocketing as it got to 30% of several thousand, which means several more thousand cases per day.

-       within another two weeks of the voluntary self-isolation measures, the raise is still on but at a slower pace. A very rough rule of thumb is that for every ten days (to max two weeks) of self-isolation, the growth rate decelerate by 5%. To be clear, figures continue to raise but at a slower rate. For example, in France, after several days of  self-isolation, the rate fell to 25% / day (statement from the French Minister of Health, February 20th, 2020).

-       Obviously this is still very scary and too fast, so most countries will then decide to go on forced self-isolation / lockdown. Again, same rule of thumb, every two weeks, the rate slows by 5%. For example, after a full week of total lockdown, the growth rate in France has gone down to 17%. 

-       Following the same reasoning, taking into accounts that lockdown measures are generally becoming stricter over time (total lockdown like decided 2 days ago in Italy), the growth rate will continue to decelerate by 5% every 10 days and should reach in between 0 to 5% mid-April.  

It is interesting to note at this stage that when the French government started with the more structured self-isolation measures, before the lockdown, at the very beginning of march, they first intended to declare a 45 days lockdown, leading us exactly to April 15th.

It is not to say that it will stop miraculously on that date. But by then, they should have also developed their testing capabilities both for the infected population but also with antibodies tests, to see who was already infected and is therefore probably immune and could get out of lockdown.

Now it is worth to explain a few things about the mortality rates. 

Indeed, on the face of it, it seems that just when the strictest measures are put in place, the number of deaths is exploding.

There is also a simple explanation for that.

First, the incubation period: before showing symptoms, and for those who are falling really ill with a life-threatening infection, the incubation period is in average 14 days.  

Second, figures recently released as based on what happened in China and what is going on in Italy is that the average period for critically ill patients to pass away is again around 14 days.

In each case above, we are talking about averages and obviously we will all tend to notice the cases of people who died in 48 hours than those who survived three weeks.

So if we look at Italy yesterday, the number of 763 deaths for a day, which is extremely frightening, relates to people who fell ill in average 28 days ago.

Italy entered into strict lockdown on March 9th, which means that beforehand, a lot of elderly people or population at risks could be infected much more easily.

In summary that means that the mortality rate will decelerate with a gap of around ten days to two weeks as compared to the deceleration in the infections growth rate.

This might be the reason why France has just declared its intention to keep the lockdown in place till the 25th of April, i.e. exactly 10 days after the 15th, when the growth should reach close to zero.

So that they will wait to make sure that the number of deaths is close to nil before releasing the pressure. That makes sense.

Before my general conclusion, I’d like to add a few words of caution.

First, these are approximations and figures can evolve quite differently on day to day comparison. For example, the growth rate in Italy had gone down to 12 – 13% but then over this week-end it went up to 26%. There may be several explanations to that, the most plausible being that as soon as one “pocket” of infected population is identified, they test another pocket and suddenly identify many new cases. 

That makes the figures above for what they are: a pattern and a trend, which has been verified in China as predicted by Michael Levitt, the Nobel Prize but could behave differently in Europe where we are not able to implement as authoritative quarantine measures than in China.

Also the fact that the patterns is showing, already, a deceleration in the growth rate in France and Italy, does not make the coronavirus less lethal in the populations at risk and therefore we need to be extremely careful.

Finally, since France and Italy were ahead of the UK, it seems that we’re in it for at least till the end of May, although if we have indeed been able to “flatten the curve”, we may have less deaths than the continental countries.

In conclusion, I would say that it is mostly a “time game”. Over time, the measures will be efficient, as long as we make sure to follow the rules and recommendation. 

The core weakness of all the countries outside China has been to have overstretched, ill-equipped, insufficiently staffed and budget-constrained Health systems. One core lesson that we need to start taking from this pandemic is to start rethinking the allocation of resources in our modern societies.

Even if they are older, there are no reason that our parents or grand-parents would have to pay for the mistakes of the governing bodies.

And what if G.od forbid, the virus had been working in reverse and affected mostly the children? Would we be ready to accept that? What kind of outcry would it generate.

In its great mercy, the Universe has spared us this scenario. This time. Urgent action is needed.