Fig. 3.

Overall disease implications of modular subdivisions in synthetic modular networks. (A) Average outbreak size, measured as the percentage of infected individuals, over increasing subdivided social networks and pathogen transmissibility. Outbreak size values have been normalized to the maximum observed outbreak. The solid line indicates epidemic threshold—namely, the threshold value of pathogen contagiousness below which there is no risk of a large outbreak ($>$10% outbreak size; Materials and Methods). (B) Epidemic robustness of networks with increasing value of relative modularity, measured as the percentage reduction in outbreak size compared with outbreak size experienced by homogeneous ($Q_{rel}=0$) networks. The solid line indicates the modularity threshold, where networks experience at least a 10% reduction in outbreak size. (C) Infection transmission events, expressed as the percentage of total outbreak size, within subgroups (local) and between subgroups (global); pathogen transmissibility = 0.18. (D) Disease implications of modular subdivisions as a function of subgroup cohesion and network fragmentation (measured as the log-number of subgroups present in the network).