Reported Tuberculosis in the United States, 2021

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Table 30. Characteristics of Tuberculosis Cases in GENType Clusters1 by Alert Levels Based on Log-Likelihood Ratio (LLR):2 United States, 2019–2021

See Surveillance Slide #62.

Characteristics of clustered tuberculosis cases by log-likelihood ratio-based alert levels.
Characteristics Unique Clustered   Alert levels for clustered cases3
Non-alerted Medium High
(LLR <5) (LLR 5 – <10) (LLR >=10)
No. (%) No. (%) No. (%) No. (%) No. (%)
Total 15,025 (80.8) 3,565 (19.2) 2,200 (61.7) 836 (23.5) 529 (14.8)
Origin of birth4
U.S.-born 3,266 (65.4) 1,726 (34.6) 782 (45.3) 528 (30.6) 416 (24.1)
Non-U.S.–born 11,723 (86.5) 1,828 (13.5) 1,409 (77.1) 307 (16.8) 112 (6.1)
Unknown or missing 36 (76.6) 11 (23.4) 9 (81.8) 1 (9.1) 1 (9.1)
Race and ethnicity5
Hispanic or Latino 4,308 (77.1) 1,277 (22.9) 846 (66.2) 292 (22.9) 139 (10.9)
American Indian or Alaska Native 85 (45.7) 101 (54.3) 15 (14.9) 21 (20.8) 65 (64.4)
Asian 6,098 (88.3) 810 (11.7) 700 (86.4) 100 (12.3) 10 (1.2)
Black or African American 2,514 (74.1) 880 (25.9) 385 (43.8) 287 (32.6) 208 (23.6)
Native Hawaiian or Other Pacific Islander 112 (47.5) 124 (52.5) 64 (51.6) 30 (24.2) 30 (24.2)
 White 1,709 (83.9) 329 (16.1) 162 (49.2) 95 (28.9) 72 (21.9)
Multiple race 131 (85.6) 22 (14.4) 12 (54.5) 5 (22.7) 5 (22.7)
Unknown or missing 68 (75.6) 22 (24.4) 16 (72.7) 6 (27.3) 0 (0.0)
Age group, years
0–4 66 (38.4) 106 (61.6) 49 (46.2) 37 (34.9) 20 (18.9)
5–14 121 (65.8) 63 (34.2) 34 (54.0) 19 (30.2) 10 (15.9)
15–24 1,344 (76.4) 416 (23.6) 251 (60.3) 120 (28.8) 45 (10.8)
25–44 4,304 (79.2) 1,127 (20.8) 643 (57.1) 294 (26.1) 190 (16.9)
45–64 4,468 (79.0) 1,185 (21.0) 726 (61.3) 256 (21.6) 203 (17.1)
≥65 4,722 (87.6) 668 (12.4) 497 (74.4) 110 (16.5) 61 (9.1)
Disease site
Pulmonary only 10,543 (79.6) 2,702 (20.4) 1,620 (60.0) 687 (25.4) 395 (14.6)
Extrapulmonary 2,507 (86.2) 403 (13.8) 274 (68.0) 61 (15.1) 68 (16.9)
Both 1,967 (81.0) 460 (19.0) 306 (66.5) 88 (19.1) 66 (14.3)
Unknown 8 (100.0) 0 (0.0) 0 0 0
Sputum smear
Positive 7,221 (78.8) 1,941 (21.2) 1,152 (59.4) 491 (25.3) 298 (15.4)
Negative 6,092 (83.0) 1,249 (17.0) 836 (66.9) 255 (20.4) 158 (12.7)
Not done 1,688 (81.9) 374 (18.1) 211 (56.4) 90 (24.1) 73 (19.5)
Unknown or missing 24 (96.0) 1 (4.0) 1 (100.0) 0 (0.0) 0 (0.0)
Cavitary disease6
Yes 158 (78.6) 43 (21.4) 29 (67.4) 7 (16.3) 7 (16.3)
No 1,329 (79.6) 341 (20.4) 232 (68.0) 62 (18.2) 47 (13.8)
Unknown or missing 16 (72.7) 6 (27.3) 3 (50.0) 2 (33.3) 1 (16.7)
Homeless within past year
Yes 510 (61.2) 324 (38.8) 168 (51.9) 75 (23.1) 81 (25.0)
No 14,371 (81.8) 3,198 (18.2) 2,010 (62.9) 750 (23.5) 438 (13.7)
Unknown or missing 144 (77.0) 43 (23.0) 22 (51.2) 11 (25.6) 10 (23.3)
Excess alcohol use within past year
Yes 1,109 (67.7) 530 (32.3) 243 (45.8) 153 (28.9) 134 (25.3)
No 13,675 (82.2) 2,956 (17.8) 1,907 (64.5) 665 (22.5) 384 (13.0)
Unknown or missing 241 (75.3) 79 (24.7) 50 (63.3) 18 (22.8) 11 (13.9)
Injecting drug use within past year
Yes 107 (51.2) 102 (48.8) 57 (55.9) 26 (25.5) 19 (18.6)
No 14,672 (81.3) 3,383 (18.7) 2,093 (61.9) 792 (23.4) 498 (14.7)
Unknown or missing 246 (75.5) 80 (24.5) 50 (62.5) 18 (22.5) 12 (15.0)
Noninjecting drug use within past year
Yes 771 (57.3) 575 (42.7) 266 (46.3) 152 (26.4) 157 (27.3)
No 14,009 (82.8) 2,913 (17.2) 1,891 (64.9) 663 (22.8) 359 (12.3)
Unknown or missing 245 (76.1) 77 (23.9) 43 (55.8) 21 (27.3) 13 (16.9)
Resident of a correctional facility at time of diagnosis
Yes 296 (69.0) 133 (31.0) 50 (37.6) 27 (20.3) 56 (42.1)
No 14,632 (81.1) 3,403 (18.9) 2,128 (62.5) 805 (23.7) 470 (13.8)
Unknown or missing 97 (77.0) 29 (23.0) 22 (75.9) 4 (13.8) 3 (10.3)
HIV status
Positive 604 (77.3) 177 (22.7) 92 (52.0) 39 (22.0) 46 (26.0)
Negative 12,811 (80.3) 3,135 (19.7) 1,943 (62.0) 735 (23.4) 457 (14.6)
Refused 313 (88.9) 39 (11.1) 22 (56.4) 15 (38.5) 2 (5.1)
Not offered 923 (84.7) 167 (15.3) 113 (67.7) 38 (22.8) 16 (9.6)
Unknown, missing or indeterminate 374 (88.8) 47 (11.2) 30 (63.8) 9 (19.1) 8 (17.0)
Multidrug-resistant TB
Yes 179 (81.0) 42 (19.0) 28 (66.7) 7 (16.7) 7 (16.7)
No 14,414 (80.7) 3,444 (19.3) 2,126 (61.7) 810 (23.5) 508 (14.8)
Unknown or missing 432 (84.5) 79 (15.5) 46 (58.2) 19 (24.1) 14 (17.7)

1GENType clusters have two or more cases with matching spoligotype and 24-locus mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) type within a county during the specified 3-year time period.
2Alert levels are based on a 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 3,565 cases in 1,241 clusters: 529 cases were in 56 (4.5%) high alert clusters; 836 cases were in 279 (22.5%) medium alert clusters, and 2,200 cases were in 906 (73.0%) 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 or Latino,” 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.”
6Cavitary disease only assessed for persons with pulmonary TB and an abnormal x-ray.

Note: Ellipses (…) indicate that the percentage cannot be calculated, and the denominator is 0.