Accessibility / Report Error

Percolation and the epidemic phenomenon: a temporal and spatial approach of the illness spread

C.B. dos SANTOS D. BARBIN A. CALIRI About the authors

The phenomenon of epidemic spread is studied, considering equally the temporal and the geographic features. The populational dynamics is described through the Monte Carlo simulation, and the idea of connectivity is used to build an analogy between percolation and the epidemic phenomenum including spatial coordinates. The model considers an idealized population distributed in a bidimentional net, and the illness spread mechanism, essentially stochastic, is processed through effective contacts between the adjacent populational neighbours. Many degrees of neighbourhood were used, as well as several degrees of spatial heterogeneity, including different immune and susceptible concentrations. A generalized concept of percolation is used as a measurement instrument, making possible the identification of an epidemic state, or phase, in a geographic feature. The results allow many concepts of Epidemiology to be taken into consideration (as mass immunity, epidemic process and state) through a wider point of view, involving explicitly the spatial dimensions. Some numeric results include: (i)- the determination of the duration of the epidemic process as a function of the initial spatial distribution of infected individuals (ii)- the effect of the "topological shield" in the reduction of the epidemic spread.

illness resistance; Monte Carlo simulation; percolation

Escola Superior de Agricultura "Luiz de Queiroz" USP/ESALQ - Scientia Agricola, Av. Pádua Dias, 11, 13418-900 Piracicaba SP Brazil, Phone: +55 19 3429-4401 / 3429-4486 - Piracicaba - SP - Brazil