Networks, mobility and mixing: Understanding the spillover and dissemination of emerging infectious disease
Every infectious disease transmission event has an ecological context and a social cause. Transmission is an inherently social event: For a transmission to occur, a susceptible individual has to come into contact with an infectious individual in a manner that allows successful transmission to occur. This contact does not need to be direct or even simultaneous (e.g., water-borne or fomite-mediated infections) but it is nonetheless ultimately contact and contact is a social event. Epidemiological contacts depend on the preferences of individual people, the social structures in which they are embedded, and the political economy that makes particular social outcomes more likely for some people than for others. These are some of the fundamental questions of the social sciences.
In this talk, I will discuss work on the formalization of social contact using the graph theoretic tools of social network analysis. I will show how structural features of networks play a key role in epidemic outcomes and, importantly, how these structural features can be exploited to improve infection control. Simulating epidemics on networks of varying structural properties, for instance, we show that preferentially vaccinating a population by their betweenness centrality reduces the final size of epidemics on networks more than a variety of alternative strategies. I will extend these insights in dicussing a large ongoing project that seeks to integrate relational (i.e., social) and spatial dependencies to understand the spillover and dissemination of novel zoonotic infections in the context of intensive land-use conversion and substantial changes in geographic mobility.