Volume 87, Number 1, July 2009
Article Number 18005
Number of page(s) 5
Section Interdisciplinary Physics and Related Areas of Science and Technology
Published online 21 July 2009
EPL, 87 (2009) 18005
DOI: 10.1209/0295-5075/87/18005

Epidemic spreading by objective traveling

Ming Tang1, 2, Zonghua Liu1 and Baowen Li2, 3

1   Institute of Theoretical Physics and Department of Physics, East China Normal University 200062 Shanghai, China
2   Department of Physics and Centre for Computational Science and Engineering, National University of Singapore 117542 Singapore
3   NUS Graduate School for Integrative Sciences and Engineering - 117456 Singapore

received 16 February 2009; accepted in final form 16 June 2009; published July 2009
published online 21 July 2009

A fundamental feature of agent traveling in social networks is that traveling is usually not a random walk but with a specific destination and goes through the shortest path from starting to destination. A serious consequence of the objective traveling is that it may result in a fast epidemic spreading, such as SARS etc. In this letter we present a reaction-traveling model to study how the objective traveling influences the epidemic spreading. We consider a random scale-free meta-population network with sub-population at each node. Through a SIS model we theoretically prove that near the threshold of epidemic outbreak, the objective traveling can significantly enhance the final infected population and the infected fraction at a node is proportional to its betweenness for the traveling agents and approximately proportional to its degree for the non-traveling agents. Numerical simulations have confirmed the theoretical predictions.

89.75.Hc - Networks and genealogical trees.
87.23.Ge - Dynamics of social systems.
87.19.X- - Diseases.

© EPLA 2009