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Reported Tuberculosis in the United States, 2021
Table 31. Tuberculosis Cases and Clusters by Cluster Size:1 United States, 2019–2021
See Surveillance Slide #61.
| Cluster size | Clusters | Cases2 | ||
|---|---|---|---|---|
| No. | (%)3 | No. | (%)4 | |
| Total | 1,241 | 100.0 | 3,565 | 100.0 |
| 2 case cluster | 836 | (67.4) | 1,672 | (46.9) |
| 3 case cluster | 206 | (16.6) | 618 | (17.3) |
| 4 case cluster | 95 | (7.7) | 380 | (10.7) |
| 5 case cluster | 30 | (2.4) | 150 | (4.2) |
| 6 case cluster | 18 | (1.5) | 108 | (3.0) |
| 7 case cluster | 12 | (1.0) | 84 | (2.4) |
| 8 case cluster | 11 | (0.9) | 88 | (2.5) |
| 9 case cluster | 4 | (0.3) | 36 | (1.0) |
| ≥10 case cluster | 29 | (2.3) | 429 | (12.0) |
1Clusters have two or more cases with matching spoligotype and 24-locus mycobacterial interspersed repetitive unit-variable number tandem repeat type (GENType) within a county during the specified 3-year time period.
2Cases with matching spoligotype and 24-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.
3Denominator is total number of clusters.
4Denominator is total number of cases.