A study of SARS-CoV-2 evolution in Italy: from early days to secondary effects after social distancing

Marco Claudio Traini; Carla Caponi; Riccardo Ferrari; Giuseppe Vittorio De Socio

One can preliminarily look at the general behavior of the Infected compartment numbers, as shown In Fig. 4 . The upper panel is in logarithmic scale in order to fit different models. In particular the simple SIR model (continuous green curve, R 0 = 3.4) largely exceed, in the hot period of the peak, the number of infected whose 5% needs intensive care (a rough estimate following the experience in China). The t-independent SEIR model containing all the stratified compartment as described by the Eqs. (1)-(8), largely lowers the peak value (cfr. [10] without reproducing the general behavior of the data (yellow squares), while the introduction of time dependence gives a prediction rather close to the observed cases. The linear curve (lower panel) only specifies the details and can be useful for further reference.