Fig. 4.

Mechanisms behind the effect of modular organization on disease spread of a moderately transmissible pathogen (= 0.1). (A) Structural delay effect in a moderately fragmented network (fragmentation = 2.30): We considered the time to disease invasion for a subgroup as the number of time steps it takes for at least 2$\%$ of individuals to acquire infection. Subgroups at the x axis are sorted according to the increasing disease invasion time. (B) Structural trapping effect in a highly fragmented network (fragmentation = 4.83): High fragmentation and subgroup cohesion localize infection to a small proportion of subgroups in the social network. Structural trapping also increases the likelihood of stochastic extinction of disease outbreaks.