My blog

I am not a doctor, so I cannot and will not speak about the virus from a medical perspective. However, I do know a bit about numbers and statistics, so I will try to look at the subject from a mathematician's perspective.

Is there anything to be afraid of? Of course, yes. And what is the source of our fear? This fear does not come from ignorance - as in the case when a mysterious figure in a hood appears in front of our house in the evening and we do not know what his intentions may be. This fear does not come from knowledge either - as in the case when we find a rattlesnake in our room on vacation, knowing how poisonous its venom is. The source of this fear is the omnipresent fear around us. The media trumpets not to leave home, the government announces every day that the worst is ahead of us, and our close friends would react to our unannounced visit with a panicky "NO" through closed doors. To be clear - my intention is not to criticize the attitude of either the media, the government or friends. On the contrary - I fully understand these attitudes, and my intention is only to try to find the rationality of our attitudes in numbers.

The World Health Organization (WHO) announced a week ago that we are dealing with a pandemic. I read on Wikipedia that a pandemic is an epidemic, i.e. a state of illness in a number greater than expected, concerning a particularly large size, over a large area covering countries and even continents. This definition is a bit imprecise. For me, a layman in this field, using so-called common sense, in order to call an infectious disease a pandemic, two conditions should be met: the first is a threat to a large number of people in the world, and the second is a deadly threat, by which I mean that the disease kills a significant percentage of those infected. The famous Spanish flu from the early 20th century killed 50 million people and therefore it can certainly be called a pandemic. But the flu, as we know it well, cannot be called a pandemic. Flu undoubtedly meets the first condition of a pandemic - "threat to a large number of people", but it does not meet the second condition - "deadly threat". In Poland, for example (according to the National Institute of Hygiene), from March 15, 2019 to March 15, 2020, almost 5 million people were infected with influenza (or were suspected of being infected), and 90 deaths due to influenza were recorded.

And how does it look in the case of coronavirus? There is no doubt that it meets the first condition. However, there is a problem with the second condition. We do not know its true mortality rate, that is, we do not know how many people died "of coronavirus". Although we learn about the growing number of deaths "of coronavirus" every day, it is worth asking whether the numbers provided really indicate how many people died of this disease. Or maybe they refer to the number of people who died who had coronavirus at the time of death, regardless of the true cause of their death?

I wonder if a patient with advanced cancer who has been infected with coronavirus comes to the hospital and dies a week later in the hospital, clearly from cancer and not coronavirus, will this case be reported in the world statistics as a death due to coronavirus or will it be omitted from these statistics? If it is reported as a death due to coronavirus? Isn't this misleading the public and overestimating the mortality rate of this disease?

Let's look at it this way. Of the 5 million Poles who caught the flu in the past year, probably tens of thousands died and were infected with the flu at the time of death. However, for some reason, these deaths were not classified as deaths due to the flu. And this seems right, because in the case of the flu, doctors probably give the cause of death that is consistent with reality. Is it the same with the coronavirus? I think not. It seems to me, or rather I am certain, that the number of deaths is not the number of victims of the coronavirus but the number of people who died having been diagnosed with the coronavirus at the time of death.

Since the beginning of the epidemic (as of March 18), Germany has reported that 7,156 people have been infected with the coronavirus and 13 have died from it. At the same time, Italy reported that the figures for them were 31,506 and 2,505, respectively. This means that for every 1,000 infected people, the virus kills 2 in Germany and 80 in Italy. How can this huge difference be explained?

This difference could be due to the fact that Italy was attacked by a different, more deadly strain of the virus. However, I do not think that it would be possible in such a short time and territorial distance. So maybe it is due to the difference in the quality of healthcare between these countries? Without a doubt, healthcare is at a higher level in Germany than in Italy - but it is not better than the Italian one by forty times and even Germany cannot stop death. So maybe the infected people who report to Italian hospitals are in a more serious condition than in Germany. This argument also seems doubtful to me, because I see no reason why the virus would choose its victims in Italy differently than in Germany. In that case, how can we explain this difference?

I see only one explanation. Germany reports the number of deaths caused by coronavirus, while Italy reports the number of deaths of people who had coronavirus. In other words, more people infected with coronavirus died in Germany than was reported, but Germany reports the number of deaths only for those who died due to coronavirus, not other diseases. And Italy reports the number of people who had coronavirus at the time of death. That's a fundamental difference, right? It's worth noting that Sudan, Guyana, Guatemala, San Marino, and Algeria report similarly to Italy. And Portugal, Austria, and Norway report similarly to Germany. Of course, this is just my hypothesis. I couldn't find any information confirming it anywhere.

The question then arises: what is the real mortality rate of the coronavirus? as reported by the Germans? 0.2%, or as reported by the Italians? 8%. This is the key issue. If this mortality rate were at the level of the German rate, then I would consider that we are not dealing with a pandemic, but just ordinary flu. However, if the real mortality rate were at the Italian level, i.e. 8% of those infected die? then we have a real problem as a world.

It is also worth noting that in early March, the head of the WHO gave four differences between the flu and the coronavirus. The first difference, according to the head of the WHO, is that the flu spreads more easily, the second, that the coronavirus has a more severe course, the third, that the mortality rate of the coronavirus is 3.4%, and of the flu less than 1%, and finally, that governments and the media have different approaches to both diseases. I checked where the number 3.4% came from. It was a number resulting from the number of deaths reported by countries around the world divided by the number of infected people. As of today, this number is 4.04%. Does it reflect the true mortality rate of this disease? I dare say not.