Un modèle mathématique des débuts de l'épidémie de coronavirus en France

Abstract

We study a two-phase S-E-I-R mathematical model, based on the current coronavirus epidemic. If contacts are reduced to zero from a certain time T close to the start of the epidemic, the final size of the epidemic is close to that obtained by multiplying the cumulative number of cases R(T) at that time by the reproduction number R0 of the epidemic. More generally, if contacts are divided at time T by q > 1 so that R0/q<1, then the final size of the epidemic is close to R(T) R0 (1-1/q)/(1-R0/q). The parameters of the model are roughly fitted to the coronavirus data in France.