Fig. 5.

Summary of Fowlkes–Mallows indices of concordance between any two partitions: (a) for pairwise comparisons of the six partitions, (b) for pairwise comparisons of each of the six partitions with the reference outbreak clusters. The Fowlkes–Mallows index can take values on the interval 0–1, where values closer to 0 indicate absence of correlation, while values closer to 1 indicate close to perfect correlation. The asterisks indicate the P values for pairwise t -test: *difference with P<0.05; **difference with P<0.01.