I’ve been reading the new book Connected by Nicholas Christakis and James Fowler that provides a take on public health through the lens of social network analysis. Christakis and Fowler introduce the “Three Degrees of Influence Rule” that claims we influence and are influenced by people up to three degrees separated from us, a majority of whom we do not know. Several studies have shown, in addition to communicable diseases, conditions such as depression, hysteria, infectious laughter, and even suicide can spread surprisingly quickly through social networks. Particularly relevant to infection control and epidemiology, they described how fellow researchers used the movement of currency, data, and phone calls to predict the movement of pathogens like SARS globally over the course of a several days. The pattern identified was a Lévy flight characterized by many short legs followed by a small number of long legs.
It’s an interesting book that has a few case studies relevant to infection control and many that are analyzed using similar principles (elections, stock markets, video games). Some food for thought and a potential intersection where those in the infection control profession and those in other professions (marketing, economics, and politics) can share ideas and interventions. Connected shows how materials, ideas, and conditions can spread in a similar fashion to infectious disease.