Fig 3. The posterior probability that each individual is the index case for a cluster versus the time of diagnosis of the individual.

The individual with highest posterior probability to be the index case is shown in red for each cluster. In some clusters, the first diagnosed case was the estimated index case, in that it had the highest probability of being the index case (e.g., CL002). In contrast, in the majority of clusters the most likely index case was not the first diagnosed individual (e.g., CL010 and CL023) or was not sampled (e.g., CL016 and CL003). The Psamp values are the posterior probability that the index case was any of the sampled individuals—in some clusters (e.g., CL003) the index case was likely to have been an unsampled individual.