Our current prime minister has been in the past often criticized as akin to Donald Trump re: conflict of interests and use of state resources to enrich himself and his family. And rightly so in my opinion, I cannot stand the man personally and politically.
However, when SARS-CoV-2 hit the Czech Republic, he, unlike Donald Trump, has done the right thing. In response to the pandemic, he has left decisions on the policy to actual epidemiology experts from the very beginning. Thus when CZ had mere 116 cases, 12 days after the first three on March 1., he declared a state of national emergency and just two days later virtually everything was put on hold except the absolute bare minimum (grocery stores, delivery services, apothecaries and some more). It was criticized by the opposition (our equivalent of US conservatives) as needless panic-making and fearmongering and the measures as needlessly draconian and a PR for himself and his party. Especially the order of mandatory face masks (home-made and improvised masks are allowed) was met with scorn.
On March 18. I have taken the data of confirmed cases so far, plotted them on a graph and calculated the best-fit exponential curve. It was at a daily increase of 39%, an effective doubling every two-three days, approsimately the same trajectory it has had all over Europe. This growth meant we should have over 140.000 cases today, but we, luckily, do not. We have less than 5.000. Howso?
Look at this graph:
The red curve is the actual cumulative cases as reported every day at midnight. The blue curve is the exponential best fit that I have calculated on March 18. And then there is the orange curve, which is also an exponential best-fit but only for the last week from March 28. to April 3. You can see that the two best-fit lines intersect on March 21.-22.
That is, in my opinion, the day when the enacted measures started to have a visible effect – eight to ten days after they were enacted. I do not know whether I am doing the right thing here mathematically – I have dabbled in statistics at work, but not in epidemiology – but it does seem right to me.
The new rate of growth is still exponential, but instead of 38% daily it is 8% daily. And although the difference between multiplying the cases daily by 1,08 instead of 1,39 does not intuitively look like much, it means the doubling of the cases is prolonged from mere 2-3 days to 10-11 days. Still not enough for an illness that can take up to 6 weeks to heal and kills 1% of infected people, but a very noticeable drop.
And AFAIK that drop is not due to insufficient testing. Testing has grown proportionally, although still not as much as it perhaps should have. But the ratio between positive/negative tests is getting lower, and that indicates that the drop in overall cases is real.
Now there is certainly much more to it than this oversimplified graph. For example, Germany took longer to enact strict active measures, relatively speaking. That is, CZ government enacted nation-wide strict measures when we had just several hundred people ill, whilst the German government did leave many decisions to individual states and instead of strict orders tried to control the situation with recommendations only at first. This has led to a bit of inconsistent reaction and different measures being enacted (and ignored by people) in different states. It worked, but not as much as was desired. Strong nation-wide measures started being implemented only when there were several thousand people ill already- at about the same time as in CZ. And at about the same weekend the curve began to break in Germany as well.
It was similar in Italy too, there the curve began to break at around March 15. (only estimated, I did not calculate the fit curves for Italy, I am doing this in OpenOffice and that is not the best program for this kind of work), about two weeks after the most-hit municipalities were put on lock-down.
Another quick analysis that can be done just by looking at the numbers – In Italy, it took 22 days for the cases to grow from about 100 to 20.000. In Germany, it took 24 days, in Spain 18 days, in UK and France 25 days and in the USA 20 days. The Czech Republic is now 24 days from its 100th case and we are nowhere near 20.000.
So even these amateurish and quick&dirty analyses show that quick reaction, regardless of what the nay-sayers say, is essential in avoiding the worst in case of an epidemic. The enacted measures work as intended. I only hope that our government and our people do not relax too soon.
Stay safe, stay at home whenever possible, and fingers crossed for you and your loved ones.