About
Key Highlights
- During 2022–2024, 18% of TB cases were part of a whole-genome multilocus sequence type (wgMLSType) cluster. Of those, 38% were part of a medium alert cluster and 23% were part of a high alert cluster.
- The percentage of cases in high alert clusters was larger among U.S.-born persons (36%) than non-U.S.–born persons (11%).
- Among race and ethnicity groups, persons identifying as American Indian or Alaska Native had the highest percentage of cases in high alert clusters (83%), and persons identifying as Asian had the lowest (8%).
- Persons reporting residence in a correctional facility at diagnosis (37%), noninjecting drug use (33%), injecting drug use (30%), and excess alcohol use (28%) were overrepresented in high alert clusters.
Data Table
Characteristics of Tuberculosis Cases in wgMLSType Clusters1 by Alert Levels Based on Log-Likelihood Ratio (LLR):2 United States, 2022–2024
| Characteristics | Unique | Clustered | Alert levels for clustered cases3 | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Non-alerted | Medium | High | ||||||||
| (LLR<4) | (LLR4 – <10) | (LLR≥10) | ||||||||
| No. | (%) | No. | (%) | No. | (%) | No. | (%) | No. | (%) | |
| Total | 17,387 | (82.1) | 3,794 | (17.9) | 1,490 | (39.3) | 1,440 | (38.0) | 864 | (22.8) |
| Origin of birth4 | ||||||||||
| U.S.-born | 2,867 | (61.7) | 1,783 | (38.3) | 502 | (28.2) | 641 | (36.0) | 640 | (35.9) |
| Non-U.S.–born | 14,441 | (87.9) | 1,996 | (12.1) | 981 | (49.1) | 793 | (39.7) | 222 | (11.1) |
| Unknown or missing | 79 | (84.0) | 15 | (16.0) | 7 | (46.7) | 6 | (40.0) | 2 | (13.3) |
| Sex | ||||||||||
| Male | 6441 | (84.2) | 1213 | (15.8) | 441 | (36.4) | 488 | (40.2) | 284 | (23.4) |
| Female | 10928 | (80.9) | 2577 | (19.1) | 1048 | (40.7) | 949 | (36.8) | 580 | (22.5) |
| Unknown or missing | 18 | (81.8) | 4 | (18.2) | 1 | (25.0) | 3 | (75.0) | 0 | (0.0) |
| Race and ethnicity5 | ||||||||||
| Hispanic or Latino | 5,922 | (76.5) | 1,819 | (23.5) | 935 | (51.4) | 679 | (37.3) | 205 | (11.3) |
| American Indian or Alaska Native | 73 | (30.3) | 168 | (69.7) | 10 | (6.0) | 18 | (10.7) | 140 | (83.3) |
| Asian | 6,611 | (94.7) | 369 | (5.3) | 170 | (46.1) | 170 | (46.1) | 29 | (7.9) |
| Black or African American | 2,725 | (75.9) | 866 | (24.1) | 194 | (22.4) | 341 | (39.4) | 331 | (38.2) |
| Native Hawaiian or Other Pacific Islander | 146 | (42.0) | 202 | (58.0) | 41 | (20.3) | 83 | (41.1) | 78 | (38.6) |
| White | 1,488 | (82.9) | 306 | (17.1) | 117 | (38.2) | 124 | (40.5) | 65 | (21.2) |
| Multiple race | 245 | (86.9) | 37 | (13.1) | 13 | (35.1) | 15 | (40.5) | 9 | (24.3) |
| Unknown or missing | 51 | (81.0) | 12 | (19.0) | 3 | (25.0) | 3 | (25.0) | 6 | (50.0) |
| Age group (years) | ||||||||||
| 0–4 | 67 | (32.7) | 138 | (67.3) | 34 | (24.6) | 70 | (50.7) | 34 | (24.6) |
| 5–14 | 145 | (58.2) | 104 | (41.8) | 28 | (26.9) | 40 | (38.5) | 36 | (34.6) |
| 15–24 | 1,748 | (75.1) | 581 | (24.9) | 252 | (43.4) | 207 | (35.6) | 122 | (21.0) |
| 25–44 | 5,284 | (78.8) | 1,422 | (21.2) | 573 | (40.3) | 552 | (38.8) | 297 | (20.9) |
| 45–64 | 4,710 | (81.1) | 1,096 | (18.9) | 404 | (36.9) | 418 | (38.1) | 274 | (25.0) |
| ≥65 | 5,405 | (92.4) | 446 | (7.6) | 196 | (43.9) | 149 | (33.4) | 101 | (22.6) |
| Unknown or missing | 28 | (80.0) | 7 | (20.0) | 3 | (42.9) | 4 | (57.1) | 0 | (0.0) |
| Disease site | ||||||||||
| Pulmonary only | 12,684 | (80.7) | 3,042 | (19.3) | 1,179 | (38.8) | 1,179 | (38.8) | 684 | (22.5) |
| Extrapulmonary | 2,473 | (90.2) | 270 | (9.8) | 114 | (42.2) | 98 | (36.3) | 58 | (21.5) |
| Both | 2,194 | (82.2) | 476 | (17.8) | 192 | (40.3) | 162 | (34.0) | 122 | (25.6) |
| Unknown or missing | 36 | (85.7) | 6 | (14.3) | 5 | (83.3) | 1 | (16.7) | 0 | (0.0) |
| Sputum smear | ||||||||||
| Positive | 8,626 | (79.6) | 2,208 | (20.4) | 864 | (39.1) | 859 | (38.9) | 485 | (22.0) |
| Negative | 7,107 | (85.0) | 1,259 | (15.0) | 514 | (40.8) | 447 | (35.5) | 298 | (23.7) |
| Not done | 1,448 | (83.7) | 282 | (16.3) | 101 | (35.8) | 114 | (40.4) | 67 | (23.8) |
| Unknown or missing | 206 | (82.1) | 45 | (17.9) | 11 | (24.4) | 20 | (44.4) | 14 | (31.1) |
| Cavitary disease6 | ||||||||||
| Yes | 6,779 | (79.0) | 1,806 | (21.0) | 715 | (39.6) | 720 | (39.9) | 371 | (20.5) |
| No | 10,188 | (84.3) | 1,903 | (15.7) | 744 | (39.1) | 690 | (36.3) | 469 | (24.6) |
| Unknown or missing | 420 | (83.2) | 85 | (16.8) | 31 | (36.5) | 30 | (35.3) | 24 | (28.2) |
| Experiencing homelessness7 | ||||||||||
| Yes | 875 | (65.2) | 467 | (34.8) | 232 | (49.7) | 140 | (30.0) | 95 | (20.3) |
| No | 16,249 | (83.2) | 3,288 | (16.8) | 1,241 | (37.7) | 1,284 | (39.1) | 763 | (23.2) |
| Unknown or missing | 263 | (87.1) | 39 | (12.9) | 17 | (43.6) | 16 | (41.0) | 6 | (15.4) |
| Excess alcohol use7 | ||||||||||
| Yes | 1,229 | (69.6) | 538 | (30.4) | 191 | (35.5) | 197 | (36.6) | 150 | (27.9) |
| No | 15,874 | (83.3) | 3,192 | (16.7) | 1,259 | (39.4) | 1,225 | (38.4) | 708 | (22.2) |
| Unknown or missing | 284 | (81.6) | 64 | (18.4) | 40 | (62.5) | 18 | (28.1) | 6 | (9.4) |
| Injecting drug use7 | ||||||||||
| Yes | 127 | (58.5) | 90 | (41.5) | 27 | (30.0) | 36 | (40.0) | 27 | (30.0) |
| No | 16,961 | (82.4) | 3,632 | (17.6) | 1,421 | (39.1) | 1,389 | (38.2) | 822 | (22.6) |
| Unknown or missing | 299 | (80.6) | 72 | (19.4) | 42 | (58.3) | 15 | (20.8) | 15 | (20.8) |
| Noninjecting drug use7 | ||||||||||
| Yes | 914 | (54.8) | 755 | (45.2) | 279 | (37.0) | 229 | (30.3) | 247 | (32.7) |
| No | 16,180 | (84.5) | 2,972 | (15.5) | 1,172 | (39.4) | 1,195 | (40.2) | 605 | (20.4) |
| Unknown or missing | 293 | (81.4) | 67 | (18.6) | 39 | (58.2) | 16 | (23.9) | 12 | (17.9) |
| Current or former smoker8 | ||||||||||
| Yes | 4532 | (78.5) | 1241 | (21.5) | 478 | (38.5) | 426 | (34.3) | 337 | (27.2) |
| No | 9800 | (84.4) | 1816 | (15.6) | 751 | (41.4) | 744 | (41.0) | 321 | (17.7) |
| Unknown or missing | 3055 | (80.6) | 737 | (19.4) | 261 | (35.4) | 270 | (36.6) | 206 | (28.0) |
| Resident of correctional facility8 | ||||||||||
| Yes | 422 | (67.7) | 201 | (32.3) | 65 | (32.3) | 61 | (30.3) | 75 | (37.3) |
| No | 16,743 | (82.5) | 3,544 | (17.5) | 1,394 | (39.3) | 1,363 | (38.5) | 787 | (22.2) |
| Unknown or missing | 222 | (81.9) | 49 | (18.1) | 31 | (63.3) | 16 | (32.7) | 2 | (4.1) |
| HIV status | ||||||||||
| Positive | 721 | (76.9) | 217 | (23.1) | 86 | (39.6) | 76 | (35.0) | 55 | (25.3) |
| Negative | 14,954 | (81.7) | 3,346 | (18.3) | 1,316 | (39.3) | 1,268 | (37.9) | 762 | (22.8) |
| Refused | 244 | (88.4) | 32 | (11.6) | 17 | (53.1) | 12 | (37.5) | 3 | (9.4) |
| Not offered | 277 | (87.9) | 38 | (12.1) | 11 | (28.9) | 18 | (47.4) | 9 | (23.7) |
| Unknown, missing, or indeterminate | 1,191 | (88.1) | 161 | (11.9) | 60 | (37.3) | 66 | (41.0) | 35 | (21.7) |
| Diabetes | ||||||||||
| Yes | 4638 | (85.7) | 772 | (14.3) | 320 | (41.5) | 325 | (42.1) | 127 | (16.5) |
| No | 11,305 | (80.8) | 2,695 | (19.2) | 1,110 | (41.2) | 965 | (35.8) | 620 | (23.0) |
| Unknown or missing | 1444 | (81.5) | 327 | (18.5) | 60 | (18.3) | 150 | (45.9) | 117 | (35.8) |
| Non-HIV immunosuppression9 | ||||||||||
| Yes | 1491 | (88.3) | 197 | (11.7) | 78 | (39.6) | 78 | (39.6) | 41 | (20.8) |
| No | 13913 | (81.4) | 3179 | (18.6) | 1325 | (41.7) | 1,171 | (36.8) | 683 | (21.5) |
| Unknown or missing | 1983 | (82.6) | 418 | (17.4) | 87 | (20.8) | 191 | (45.7) | 140 | (33.5) |
| Multidrug-resistant TB10 | ||||||||||
| Yes | 265 | (88.9) | 33 | (11.1) | 7 | (21.2) | 21 | (63.6) | 5 | (15.2) |
| No | 16,395 | (82.0) | 3,593 | (18.0) | 1,419 | (39.5) | 1,353 | (37.7) | 821 | (22.8) |
| Unknown or missing | 727 | (81.2) | 168 | (18.8) | 64 | (38.1) | 66 | (39.3) | 38 | (22.6) |
1Clusters have two or more cases with matching whole-genome multilocus sequence type (wgMLSType).
2Alert levels are based on a LLR log-likelihood ratio, which calculates the geographical concentration of a genotype in a county compared to the rest of the country during a 3-year period.
3There were 3,794 cases in 1,268 clusters: 864 cases were in 89 (7.0%) high alert clusters; 1,440 cases were in 536 (42.3%) medium alert clusters, and 1,490 cases were in 643 (50.7%) non-alert clusters.
4Persons born in the United States, certain U.S. territories, or elsewhere to at least one U.S. citizen parent are categorized as U.S.-born. All other persons are categorized as non-U.S.–born.
5Persons who identified as Hispanic or Latino were categorized as "Hispanic," regardless of self-reported race. Persons who did not identify as Hispanic or Latino were categorized by self-reported race; if more than one race was reported, the person was categorized as "Multiple race." Due to "Other race" being first reported as a new race category in 2023, information for 126 persons reporting "Other race" was not included in this table.
6Evidence of cavitation on any chest imaging (X-ray, computed tomography [CT], magnetic resonance imaging [MRI], or positron emission tomography [PET]).
7Within 12 months prior to TB diagnostic evaluation.
8At the time of TB diagnostic evaluation.
9Includes tumor necrosis factor-α (TNF) inhibitors, post-organ transplantation, immunosuppressive therapy, and other immunosuppressive medical conditions such as malignancy.
10Starting in 2023, information on drug resistance included results of molecular drug susceptibility testing in addition to growth-based susceptibility testing for isoniazid and rifampin. An isolate is considered resistant to isoniazid or rifampin if either the growth-based test or molecular test detects resistance.
Notes
Data for all years are updated through July 10, 2025.