<jats:title>Abstract</jats:title><jats:p>A great variety of complex physical, natural and artificial systems are governed by statistical distributions, which often follow a standard exponential function in the bulk, while their tail obeys the Pareto power law. The recently introduced<jats:inline-formula><jats:alternatives><jats:tex-math>$$\kappa $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>κ</mml:mi></mml:math></jats:alternatives></jats:inline-formula>-statistics framework predicts distribution functions with this feature. A growing number of applications in different fields of investigation are beginning to prove the relevance and effectiveness of<jats:inline-formula><jats:alternatives><jats:tex-math>$$\kappa $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>κ</mml:mi></mml:math></jats:alternatives></jats:inline-formula>-statistics in fitting empirical data. In this paper, we use<jats:inline-formula><jats:alternatives><jats:tex-math>$$\kappa $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>κ</mml:mi></mml:math></jats:alternatives></jats:inline-formula>-statistics to formulate a statistical approach for epidemiological analysis. We validate the theoretical results by fitting the derived<jats:inline-formula><jats:alternatives><jats:tex-math>$$\kappa $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>κ</mml:mi></mml:math></jats:alternatives></jats:inline-formula>-Weibull distributions with data from the plague pandemic of 1417 in Florence as well as data from the COVID-19 pandemic in China over the entire cycle that concludes in April 16, 2020. As further validation of the proposed approach we present a more systematic analysis of COVID-19 data from countries such as Germany, Italy, Spain and United Kingdom, obtaining very good agreement between theoretical predictions and empirical observations. For these countries we also study the entire first cycle of the pandemic which extends until the end of July 2020. The fact that both the data of the Florence plague and those of the Covid-19 pandemic are successfully described by the same theoretical model, even though the two events are caused by different diseases and they are separated by more than 600 years, is evidence that the<jats:inline-formula><jats:alternatives><jats:tex-math>$$\kappa $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>κ</mml:mi></mml:math></jats:alternatives></jats:inline-formula>-Weibull model has universal features.</jats:p>