An official website of the United States government
Reported Tuberculosis in the United States, 2018
Table 25. Tuberculosis Cases and Clusters, by Cluster Size1: United States, 2016–2018
See Surveillance Slide #40
| Cluster Size | Clusters | Cases2 | ||
|---|---|---|---|---|
| No. | (%)3 | No. | (%)4 | |
| Total | 1,349 | (100.0) | 4,001 | (100.0) |
| 2-case cluster | 893 | (66.2) | 1,786 | (44.6) |
| 3-case cluster | 224 | (16.6) | 672 | (16.8) |
| 4-case cluster | 90 | (6.7) | 360 | (9.0) |
| 5-case cluster | 42 | (3.1) | 210 | (5.2) |
| 6-case cluster | 33 | (2.4) | 198 | (4.9) |
| 7-case cluster | 21 | (1.6) | 147 | (3.7) |
| 8-case cluster | 5 | (0.4) | 40 | (1.0) |
| 9-case cluster | 12 | (0.9) | 108 | (2.7) |
| ≥10-case cluster | 29 | (2.1) | 480 | (12.0) |
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.
2Cases 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.
3Denominator is total number of clusters.
4Denominator is total number of cases.