TABLE 1.

Characteristics of the TG classified in this study

TG	No. of patients	Description
1	44	Patients with a clear epidemiological link, confirmed by IS6110-PGRS typing
2	13	Patients with links as clear as those in TG1, confirmed by IS6110-PGRS typing, who should have been, but were not, detected by contact tracing
3	54	Patients with an epidemiological link which was initially unclear but became likely after IS6110-PGRS typing and the second interview
4	14	Patients for whom meticulous analysis of all available data ruled out an epidemiological link but whose IS6110-PGRS typing results suggested that they belonged to a certain cluster