About
Key Highlights
- Six large outbreaks of TB detected in 2024 involved a total of 129 cases. Approximately half (53%) of cases in these outbreaks occurred in U.S.-born persons.
- Children <15 years old accounted for 36% of cases in large outbreaks.
- No outbreak cases had TB disease that was resistant to isoniazid or rifampin.
- Nearly 80% of outbreak cases were identified through contact investigations.
Data Table
Characteristics of Tuberculosis Cases in New Large Outbreaks:1 United States, 2024
| Characteristic | No. | (%) |
|---|---|---|
| Total | 129 | (100.0) |
| Genotyped cases | 48 | (37.2) |
| Origin of birth2 | ||
| U.S.-born | 68 | (52.7) |
| Non-U.S.–born | 61 | (47.3) |
| Unknown or missing | 0 | (0.0) |
| Sex | ||
| Male | 58 | (45.0) |
| Female | 71 | (55.0) |
| Unknown or missing | 0 | (0.0) |
| Age group (years) | ||
| 0–4 | 22 | (17.1) |
| 5–14 | 24 | (18.6) |
| 15–24 | 14 | (10.9) |
| 25–44 | 43 | (33.3) |
| 45–64 | 20 | (15.5) |
| ≥65 | 6 | (4.7) |
| Unknown or missing | 0 | (0.0) |
| Disease site | ||
| Pulmonary only | 119 | (92.2) |
| Extrapulmonary only | 2 | (1.6) |
| Both pulmonary and extrapulmonary | 8 | (6.2) |
| Unknown or missing | 0 | (0.0) |
| Sputum smear | ||
| Positive | 39 | (30.2) |
| Negative | 59 | (45.7) |
| Not done | 31 | (24.0) |
| Unknown or missing | 0 | (0.0) |
| Cavitary disease3 | ||
| Yes | 14 | (10.9) |
| No | 113 | (87.6) |
| Unknown or missing | 2 | (1.6) |
| Previous diagnosis of TB or LTBI4 | ||
| LTBI only | 7 | (5.4) |
| TB disease only | 0 | (0.0) |
| Both LTBI and TB disease | 0 | (0.0) |
| None | 113 | (87.6) |
| Unknown or missing | 9 | (7.0) |
| HIV status | ||
| Positive | 2 | (1.6) |
| Negative | 106 | (82.2) |
| Refused | 0 | (0.0) |
| Not offered | 20 | (15.5) |
| Unknown, missing, or indeterminate | 1 | (0.8) |
| Non-HIV immunosuppression5 | ||
| Yes | 4 | (3.1) |
| No | 108 | (83.7) |
| Unknown or missing | 17 | (13.2) |
| Diabetes | ||
| Yes | 14 | (10.9) |
| No | 107 | (82.9) |
| Unknown or missing | 8 | (6.2) |
| End-stage renal disease | ||
| Yes | 1 | (0.8) |
| No | 121 | (93.8) |
| Unknown or missing | 7 | (5.4) |
| Viral hepatitis | ||
| Yes | 6 | (4.7) |
| No | 118 | (91.5) |
| Unknown or missing | 5 | (3.9) |
| Experiencing homelessness6 | ||
| Yes | 9 | (7) |
| No | 119 | (92.2) |
| Unknown or missing | 1 | (0.8) |
| Excess alcohol use6 | ||
| Yes | 9 | (7) |
| No | 119 | (92.2) |
| Unknown or missing | 1 | (0.8) |
| Injecting drug use6 | ||
| Yes | 5 | (3.9) |
| No | 124 | (96.1) |
| Unknown or missing | 0 | (0.0) |
| Noninjecting drug use6 | ||
| Yes | 14 | (10.9) |
| No | 115 | (89.1) |
| Unknown or missing | 0 | (0.0) |
| Resident of correctional facility7 | ||
| Yes | 0 | (0.0) |
| No | 128 | (99.2) |
| Unknown or missing | 1 | (0.8) |
| Resident of long-term care facility7 | ||
| Yes | 0 | (0.0) |
| No | 129 | (100.0) |
| Unknown or missing | 0 | (0) |
| Initial reason of evaluation for TB disease | ||
| Contact investigation | 103 | (79.8) |
| Screening | 1 | (0.8) |
| TB symptoms | 21 | (16.3) |
| Other | 3 | (2.3) |
| Unknown or missing | 1 | (0.8) |
| Resistant to isoniazid or rifampin8 | ||
| Yes | 0 | (0.0) |
| No | 49 | (100.0) |
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1Defined as 10 or more cases of tuberculosis related by recent transmission during a 3-year period. These large outbreaks met the minimum of 10 cases in 2024, but might also include cases reported during 2021–2024. Cases from ongoing large outbreaks that were detected before 2024 are not included.
2Persons 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.
3Evidence of cavitation on any chest imaging (X-ray, computed tomography [CT], magnetic resonance imaging [MRI], or positron emission tomography [PET]).
4LTBI, latent tuberculosis infection.
5Includes persons receiving tumor necrosis factor-α (TNF-alpha) inhibitors at time of diagnostic evaluation, persons who have ever received a solid organ transplant, and persons who have ever been immunocompromised because of a medical condition (other than HIV) or immunosuppressive therapy.
6Within 12 months prior to TB diagnostic evaluation.
7At the time of TB diagnostic evaluation.
8Among persons with susceptibility results for at least isoniazid and rifampin. Starting 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.
See Technical Notes.