INTRODUCTION
The modelling of epidemics has been the object of
a vast number of studies over the past century.
The desire to understand their mechanism has led to
the formulation of models which make possible the
simulation of events for which laboratory experiments
cannot be conducted easily. Such approaches include
reaction-diffusion models,and may include nonlinear
incidence rates in compartmented models , use
travelling waves equations,and non-local delayed
terms.