Time evolution of non-lethal infectious diseases: a semi-continuous approach.

A model describing the dynamics related to the spreading of non-lethal infectious diseases in a fixed-size population is proposed. The model consists of a non-linear delay-differential equation describing the time evolution of the increment in the number of infectious individuals and depends upon a limited number of parameters. Predictions are in good qualitative agreement with data on influenza, which is taken to be a representative type of non-lethal infectious disease. © EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2006.