The Internet, as well as many other networks, has a very complex connectivity recently modeled by the class of scale-free networks. This feature, which appears to be very e cient for a communications network, favors at the same time the spreading of computer viruses. We analyze real data from computer virus infections and nd the average lifetime and prevalence of viral strains on the Internet. We de ne a dynamical model for the spreading of infections on scale-free networks, nding the absence of an epidemic threshold and its associated critical behavior. This new epidemiological framework rationalize data of computer viruses and could help in the understanding of other spreading phenomena on communication and social networks.
Pastor-Satorras and Vespignani analyze real data from computer virus infections in order to define a dynamical SIS model for epidemic spreading in scale-free networks REF .
Epidemic Spreading in Scale-Free Networks
Phys. Rev. Lett. 86, 3200 (2001)
Physics Medicine