title: Velocity and hierarchical spread of epidemic outbreaks in scale-free networks.
abstract: We study the effect of the connectivity pattern of complex networks on the propagation dynamics of epidemics. The growth time scale of outbreaks is inversely proportional to the network degree fluctuations, signaling that epidemics spread almost instantaneously in networks with scale-free degree distributions. This feature is associated with an epidemic propagation that follows a precise hierarchical dynamics. Once the highly connected hubs are reached, the infection pervades the network in a progressive cascade across smaller degree classes. The present results are relevant for the development of adaptive containment strategies.
authors.affiliation: CEA-Centre d'Etudes de Bruyères-le-Châtel, Département de Physique Théorique et Appliquée, BP12, 91680 Bruyères-Le-Châtel, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Barthélemy
authors.forename: Alain
authors.initials: A
authors.lastname: Barrat
authors.forename: Romualdo
authors.initials: R
authors.lastname: Pastor-Satorras
authors.forename: Alessandro
authors.initials: A
authors.lastname: Vespignani
mesh_terms: D004196:Disease Outbreaks; D007114:Immunization / Q000379:methods; D007239:Infections / Q000453:epidemiology / Q000635:transmission; D008962:Models, Theoretical; D016012:Poisson Distribution