https://popups.uliege.be/3041-539x/index.php?id=613 The spread of an epidemic can be studied on a discrete space into small cells arranged into a ds-dimensional regular lattice [Durett & Levin, 1994]. Each sites are occupied by healthy individuals may be infected by neighbours, after which they recover completely, they recover and are subsequently immune, or they die. Such a model is a generalisation of the differential equation approach. It corresponds to a modification of the directed percolation problem, useful to describe a large number of disordered systems in physics and chemistry. A critical concentration separate a phase where the epidemic dies out after a finite number of time steps, from a phase where the epidemic can continue forever. In the simplest models, we assume that the vicinity, in which the infection process takes place, is a small domain surrounding the healthy individual considered. This vicinity is made up of the first layers of M = 3ds-1 cells surrounding the central cell considered (Moore neighbourhood). The purpose of this article is to generalise the dimension of the substrate by introducing a fractal distribution of the sites. For each distribution of infected individuals in this vicinity, there is a certain probability ξ of infection. Due to the self-similarity, the infection quantities are significantly modified on fractal substrate. The fractal distribution of the sites can be related to the spatial distribution of the epidemic vector [Meltzer, 1991]. Vector distribution is a matter of suitable habitat, which is a sum of a wide range of environmental factors (humidity, soil moisture, ground temperature, parasitic-host population density, etc..). The distribution of the sites can be also related to the genetic distribution of the susceptibility of the host population. In a herd, the laws of inheritance form a discrete and recursive system which mixes and distributes the genes of susceptibility. We can propose an aggregation model of relatives around an individual, which is based on the direct inheritance. Full text issues Volume 1 Biological and Ecological Systems fr Fri, 28 Jun 2024 14:53:50 +0200 Fri, 28 Jun 2024 14:53:58 +0200 https://popups.uliege.be/3041-539x/index.php?id=613 0