Size and timescale of epidemics in the SIR framework

Mariano Cadoni; Giuseppe Gaeta

doi:10.1016/j.physd.2020.132626

Size and timescale of epidemics in the SIR framework

Physica D. 2020 Oct:411:132626. doi: 10.1016/j.physd.2020.132626. Epub 2020 Jun 20.

Authors

Mariano Cadoni^{1

2}, Giuseppe Gaeta^{3

4}

Affiliations

¹ Dipartimento di Fisica, Università di Cagliari, Cittadella Universitaria, 09042 Monserrato, Italy.
² INFN, Sezione di Cagliari, 09042 Monserrato, Italy.
³ Dipartimento di Matematica, Università degli Studi di Milano, via Saldini 50, 20133 Milano, Italy.
⁴ SMRI, 00058 Santa Marinella, Italy.

Abstract

The most important features to assess the severity of an epidemic are its size and its timescale. We discuss these features in a systematic way in the context of SIR and SIR-type models. We investigate in detail how the size and timescale of the epidemic can be changed by acting on the parameters characterizing the model. Using these results and having as guideline the COVID-19 epidemic in Italy, we compare the efficiency of different containment strategies for contrasting an epidemic diffusion such as social distancing, lockdown, tracing, early detection and isolation.

Keywords: COVID-19 Epidemic; Mathematical Modelling of Epidemics; SIR Model.