Pandemics are increasingly frequent and probable: this is stated by an international team of researchers with a study (published in PNAS) conducted by the University of Padua, which reads that the probability that a pandemic like that of CoViD-19 occurs in a any moment is for now, every year, around 2%, but also that the trend is increasing and that it could triple in the coming decades. “The frequency with which new epidemic diseases emerge from animal reservoirs has increased in recent decades due to anthropogenic environmental changes”, explains Marco Marani, head of the study, stressing that we are not yet prepared for epidemics of great intensity (as we said in unsuspected times), which are however far from unlikely.
Four hundred years of history. For the study, the researchers analyzed data from four centuries of major epidemics (1600-2020). The Spanish flu has reconfirmed itself as the most serious pandemic in history: the estimates of the dead, all rather inaccurate, are between 50 and 100 million. In any case, a massacre, considering that the world population at the time did not reach two billion people. The intensity of the Spanish epidemic, defined by the authors as the number of victims divided by the duration of the epidemic and normalized with respect to the world population of the time, was about 5.7 per thousand / year: to get an idea of what this could mean, covid has so far shown to have an intensity of 0.3 per thousand / year, about 20 times less.
More or less probable scenarios. The chances of a Spanish intensity pandemic occurring again are between 0.3% and 1.9% per year, for the period studied: in other words, statistically speaking it is likely that a “Spanish 2.0” you get there between head and neck within the next 400 years. This does not mean, however, that we can rest assured for at least three centuries: such a lethal virus could develop in two, ten, one hundred or two hundred years, with the same probability. For a “covid 2.0” we may instead have to wait only 59 years, again according to statistical data: in short, it is very likely that another pandemic will touch us in the course of our life, or that of our children or grandchildren.
The study also calculated the possibility of a pandemic that could wipe mankind off the face of the Earth. It is probable that it will happen within the next 12,000 years: but, as we said, it does not mean that it cannot happen in one, ten, two hundred, one thousand, three thousand …