Impact of individual behavioral decisions and interaction structure on the spread of infectious disease in an ecosystem

Background/Question/Methods

Decisions that individuals make in terms of their interaction choices affect not only their own performance, but also have a broader impact on the community of organisms with which they interact.  Such decisions may also affect the flow of information in a population, most notably the dynamics of disease transmission among individuals. With their ability to quantify both the success of embedded individuals and the interaction structure of a group, social networks offer intriguing opportunities to investigate the impact of individual decisions and interaction selectivity on the spread of communicable diseases in populations and ecosystems. To this effect, and in addition to utilizing their analytical properties, we used social networks to develop a simulation framework capable of modeling systems in which affiliations between individuals change dynamically in response to, the individual. The addition of a contagion to this framework allowed us to study the consequences of individual behavioral decisions at different levels of biological organization, from individuals to ecosystems.

Results/Conclusions

Our results demonstrated that social behaviors exhibited by individuals can determine whether a population, or a species, acts as a source or a sink for pathogens in an ecosystem. Populations that used different rules to guide their social interactions suffered different disease loads, and also suffered different levels of intra- and inter-population infections. These results are especially important at an ecosystem level and for contagions which can cross species barriers, as they demonstrate the importance of social behaviors as factors that impact the individual and the population within which it is embedded, but also other populations in contact with this population. Such approach is therefore well suited for use in studies concerned with impacts of wildlife disease on functioning and health of ecosystems, as well as conservation and management of populations - especially those consisting of small interacting groups. Our results also cast a new light on the role of social behavior in human-wildlife interactions, as well as human-vector interactions in zoonoses.