A Comparison of Simulation Models Applied to Epidemics

This paper presents a new approach to infectious disease analysis through computer simulation. The case study concerns the spread of Bovine Leukemia, a viral pathology sustained by a retrovirus from the same family as HIV that exclusively strikes cattle within dairy farms. Although analytical models of epidemic spread have been implemented, their practical use is often difficult, above all for predictive and quantitative analysis. Computer simulation provides a new possible approach, and here we apply two methodologies: "System Dynamics" and "Agent Based". Furthermore the case study is used like a workbench to illustrate the differences between the two approaches and to explain how these techniques can help with the understanding of the problem. At the same time epidemiological researchers are able to do a preliminary "what-if" analysis with the purpose of assessing the system's behaviour under various conditions and evaluating which alternative sanitary policies to adopt. Thanks to model results, experts have reached their first suppositions in order to fight the endemic behaviour of Bovine Leukemia. The models implemented can easily be extended to collect the details of the system to be investigated more efficiently and to allow more refined analyses to be made.