[PYTHON] [Introduction to infectious disease model] Looking at the logarithmic graph. .. .. It's the second wave! ??

I predicted that it was about to end two months ago, This time, the spread of infection is occurring again in Tokyo and all over the country, so I will draw a logarithmic graph to evaluate how dangerous it is. The application used and the data collection method (obtained from the Ministry of Labor page) are almost the same as the last time.

The last outbreak occurred from late March to early April (there was a time delay of about two weeks, so the peak infection was actually from mid-March to early April), and a state of emergency was declared and somehow ended. .. This time, after the state of emergency was lifted and the Tokyo alert was lifted, it seems that looseness has come out to this day.

The increase in Tokyo is dangerous

Looking at the graph, it is as follows. (Transition from June 1st) Looking at this graph, the number of new infections is gradually increasing and has finally exceeded 100 for 3 consecutive days (111 for 4 consecutive days today). However, the actual current number of patients is very small compared to the green plot of total cures, as the red plot shows. Then, I would like to discuss whether it is okay as it is.

To that end, let's take a look at how the number of infections changed from the end of March to April last time. (Transition from March 27) Looking at this, we can see that the peak value in early April was around 200 people. And if the above graph is represented on the same scale as this, it will be as follows. Looking at this, it is true that the bar graph also increased, and the red plot also started to increase suddenly, but it seems that it is still less than the above figure. But what about a logarithmic plot of this as shown below? And now Comparing these two graphs, we can see that the current bar and red plots have reached a line similar to the explosive increase from late March to April. In other words, that's what exponential growth is, and it tends to grow quickly. The rate of increase this time, I think, is very similar to the rate of increase (slope) of the previous time. In other words, the number of new infections has a slope of about 10 times / month. In addition, the red plot has a slope of about 10 times / 2w. In other words, the number of new infections in Tokyo is likely to rise to about 1000 in a month. Before that, the red plot, that is, the number of existing infections, which is proportional to the number of hospitalizations, is likely to reach the level of 10,000 in about two weeks. Two weeks is an important time, and even if you take some measures now, two weeks will come before the measures are effective. So, looking at these graphs, I think it is important to take effective measures as soon as possible to reduce this tendency.

• However, it is thought that this was caused by the relaxation of the feeling of liberation, so I think it was necessary to take measures to show the feelings and actions properly again.

Actually, the whole country is also dangerous

Naturally, the cancellation of the state of emergency was carried out nationwide. So, let's compare the national data with the data from late March to April and the current data.

The linear scale is as follows Data from late March to April Current data In the above comparison, it is still small, so it seems to be okay for the time being. However, this also changes suddenly as shown below when logarithmically plotted. Data from late March to April Current data In other words, if the number of new infections exceeds 200, the 700th level of the previous peak will be reached in about a week in a blink of an eye. In other words, it is likely that the number of new infections and the number of infected people will exceed the previous peak, although it is likely that the danger will be detected and it will slow down a little in the future.

The problem is the measures after this

The problem is the story after this. After all, you should declare a state of emergency as soon as possible and take the initial response. I don't think it is necessary to take measures to stop the economy again. Tighten the loose spirit and devise each one ・ Social distance ・ Do not gather ·mask ・ Hand wash ・ Unnecessary and unurgent movement refrain ・ Avoiding 3 honey at work and playground ．．． In short, I think we should aim for 80% reduction again.

I think that we should utilize the know-how we have cultivated so far to improve the measures to prevent infection and prevent infection every day while turning the economy. If this is not the case, it is thought that the number of affected people, mainly young people, will now expand to the elderly and those with underlying illnesses, leading to an unexpected increase in the number of victims that are encountered overseas at worst.

Summary

・ Logarithmic plot of the current spread of infection and comparison with the previous spread of infection ・ The current spread of infection is already on a scale that can be called the second wave, and if left untreated, it is thought that it will exceed the previous spread of infection.

・ I thought about fitting with an infectious disease model, but the aftermath of the first wave remains as the number of cures and deaths, and it is not possible to make a reasonable calculation without devising.