Figure 3

Underlying transmission dynamics in urban and rural models. We fit urban and rural models to the distribution of transmission cluster size data to infer the degree of individual heterogeneity in secondary cases. While all models show that TB transmission is characterized by a high degree of individual heterogeneity, the rural model suggests a substantially higher propensity for explosive outbreaks of recent transmission. (A) Probability of observing large outbreaks originating from a single index case; (B) Probability density of expected number of secondary cases for each individual (i.e., underlying individual reproductive number, \(\nu\)). The uncertainty interval integrates across the entire range of 95% confidence intervals for both \(\hat{R}\) and \(\hat{k}\).