Reported Tuberculosis in the United States, 2017

Return to Main Menu

Table 25. Tuberculosis Cases and Clusters, by Cluster Size1: United States, 2015–2017

Table 25. Tuberculosis Cases and Clusters, by Cluster Size: United States, 2015-2017
Cluster Size Clusters Cases2
No. (%)3 No. (%)4
Total 1,409 (100.0) 4,259 (100.0)
2 case cluster 928 (65.9) 1,856 (43.6)
3 case cluster 229 (16.3) 687 (16.1)
4 case cluster 110 (7.8) 440 (10.3)
5 case cluster 46 (3.3) 230 (5.4)
6 case cluster 22 (1.6) 132 (3.1)
7 case cluster 17 (1.2) 119 (2.8)
8 case cluster 11 (0.8) 88 (2.1)
9 case cluster 10 (0.7) 90 (2.1)
≥10 case cluster 36 (2.6) 617 (14.5)

1 Clusters have two or more cases with matching spoligotype and 24-locus locus mycobacterial interspersed repetitive unit-variable number tandem repeat type (GENType) within a county during the specified 3-year time period.
2 Cases with matching spoligotype and 24-locus locus mycobacterial interspersed repetitive unit-variable number tandem repeat type (GENType) are members of a cluster within a county during the specified 3-year time period.
3 Denominator is total number of clusters.
4 Denominator is total number of cases.