Optimizing Hybrid Spreading in Metapopulations

Abstract

Epidemic spreading phenomena are ubiquitous in nature and society. Examples include the spreading of diseases, information, and computer viruses. Epidemics can spread by local spreading, where infected nodes can only infect a limited set of direct target nodes and global spreading, where an infected node can infect every other node. In reality, many epidemics spread using a hybrid mixture of both types of spreading. In this study we develop a theoretical framework for studying hybrid epidemics, and examine the optimum balance between spreading mechanisms in terms of achieving the maximum outbreak size. We show the existence of critically hybrid epidemics where neither spreading mechanism alone can cause a noticeable spread but a combination of the two spreading mechanisms would produce an enormous outbreak. Our results provide new strategies for maximising beneficial epidemics and estimating the worst outcome of damaging hybrid epidemics.

Hybrid Epidemics—A Case Study on Computer Worm Conficker

“…We are interested in the critically hybrid epidemic, where each spreading mechanism alone is unable to cause any significant spreading whereas the mixture of such mechanisms leads to a huge epidemic outbreak. Recently we proposed a model that explains the behaviour of critically hybrid epidemics, which incorporates two spreading mechanisms in the setting of a metopopulation [16]. We demonstrated that it is indeed possible to have a highly contagious epidemic by mixing simple, ineffective spreading mechanisms.…”

“…Recently we proposed a generic model to study the critically hybrid epidemics [16]. We considered an epidemic which spreads in a meta-population (consisting of many weakly connected sub-populations) using a mix of the following two typical spreading mechanisms.…”

“…In our Conficker model, we set the local and global population as fully mixed, because this is how the Conficker worm perceives the structure of the Internet. We considered more complex network structures in a separate work [16] where we studied hybrid epidemics in general.…”

Multi-season analysis reveals the spatial structure of disease spread

“…In reality, many epidemics spread through a combination of two or more spreading mechanisms; hybrid spreading [5]. Such spreading can be modeled by multiple compartments encompassing different demographic characteristics [4], various disease strains [6,7,8,9,10], and cross-immunity in an age structured model [11,12,13].…”

“…In the absence of actual data, the spreading topology can generally be analyzed by numerical simulation of models using synthetic data, for example, of the patterns of human movements at the desired scale [16,17]. It can also be analyzed through the use of theoretical tools to detect critical phenomena in networks [18,19,5].…”