Evolution of Covid-19

If we look at the cases of Covid-19 detected and the number of deaths produced on the website of the World Health Organization (WHO), we see that all the countries of the world show an approximately similar evolution. Initially there is a very sudden increase in infections according to a function mathematically close to an exponential, then the curve smoothes out and describes a more or less prolonged plateau, and finally it follows a progressive and long descent. The general shape could resemble the boa that has swallowed an elephant, from the famous story “The Little Prince”. This curve is surprisingly similar throughout the world, regardless of the health management that has been carried out. Absolute values ​​vary enormously between different countries, but the shape of the curve does not. This could indicate an internal dynamics of the epidemic and makes it comparable to a fire. Two elements are needed for a fire: the fuel (wood), and the oxidizer (oxygen). The forest fire always starts from a small spark and gradually grows. Depending on the environmental conditions (wind, slope and degree of humidity) it can burn a few tens or millions of hectares, and even if nobody turned it off, it would end self-extinguishing, although there is still fuel and oxidizer. An epidemic also needs fuel (people) and oxidizer (infectious agent), it starts from a spark (first patient) and grows gradually until it affects hundreds, thousands or millions of people. If we did not intervene, it would end self-extinguishing although there would continue to be people who could be infected and an infectious agent. Both the fire and the epidemic can show outbreaks in their final stages. The question is to what extent the coronavirus will behave like the flu, or Mediterranean fires, which recur seasonally. The good news is that we have now improved the fire department.