Summary of results of the transmission analysis. Each horizontal panel corresponds to one of the 15 groups defined in Figure 1a. Each circle represents a CDI case, and is located on the x-axis according to the isolation date. Cases are linked by horizontal lines where the genomic analysis found that transmission was possible. The 15 genomes in group 9 are labeled from A to O as in Figure 1b. Within each group, cases that are connected with one another based on the epidemiological analysis are indicated by circles of the same unique color, and cases with no identified epidemiological connections are shown in gray. The same colors are used to label isolates in Additional file 3.