TABLE 1.

Clustering of M. tuberculosis isolates in Norway from 1994 to 1998 based on IS6110 and DR fingerprinting

Clustering using IS6110 probe				Clustering using DR probe
No. of IS6110 copies	No. of isolates	No. of clusters	Cluster sizea	No. of nonclustered isolates	No. of clusters	Cluster sizea	Country of origin of patients in clusters (no. of patients)
0	4			2	1	2	Vietnam (1), Pakistan (1)
1	54	4	27	15	5	3	Somalia (3)
						3	Sri Lanka (2), Pakistan (1)
						2	Somalia (1), Vietnam (1)
						2	Vietnam (1), Thailand (1)
						2	Somalia (1), Ethiopia (1)
			2	2	0
			15	4	2	9	Vietnam (9)
						2	Somalia (2)
			10	2	1	8	Ethiopia (1), Norway (4), Somalia (3)
2	6	0		6	0
3	11	1	2	9	1	2	Somalia (2)
4	6	1	3	6	0

^aCluster size is expressed as the number of isolates per cluster.