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Reported Tuberculosis in the United States, 2017
Table 25. Tuberculosis Cases and Clusters, by Cluster Size1: 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.