An interesting point from Jon Zelner:

The idea behind this paper [by Zelner, James Trostle, Jason Goldstick, William Cevallos, James House, and Joseph Eisenberg] is that epidemiologists typically think of social networks as structures defining some kid of contact risk at the individual level, i.e. who-transmits-to-who, but not how these networks might be protective or otherwise structure risk at the community level.

In this paper, we showed that in a group of villages in rural Ecuador, network density was predictive of increased water sanitation quality and, consequently, decreased infectious disease risk. We argued that this is because these networks tell us something about social cohesion and investment in these communities, where it still takes a lot of effort to build and maintain effective water sanitation systems. The strength of this paper is that the data are really cool and unique (from a great project run in part by my PhD advisor at Michigan, Joe Eisenberg, called EcoDess). But we also did some mediation analysis to show that the village networks and water sanitation infrastructure explain the same part of the variance in the infectious disease outcomes. If I was doing it today, it’d probably look like more of a hierarchical model, but I think this still does a good job of getting the point across and makes a kind of unique argument about the relationship between community cohesion and disease risk.


Diagram from Zelner et al. paper on factors that can affect the spread of disease.

Zelner and his colleagues studied the spread of diarrhea in a group of rural villages in Ecuador. This research is potentially important because we’re used to thinking about networks and social contacts in this context as a way of spreading disease, but networks spread information, as well.