Between 2017 and 2023, the US Centers for Disease Control and Prevention investigated 50 large tuberculosis outbreaks across 23 states, accounting for 1,092 cases (Raz et al., Morbidity and Mortality Weekly Report, Volume 75, Issue 16, April 30, 2026). Black or African American patients made up 42 percent of those outbreak-associated cases, compared with about 9 percent of non-outbreak US TB cases over the same period. That is a 4.7-fold over-representation of Black patients inside outbreak settings relative to the non-outbreak baseline, in a country with one of the lowest national TB incidence rates in the world.
Of the 50 outbreaks, 34 (68 percent) were primarily associated with family or social networks. Thirteen (26 percent) were primarily associated with congregate settings: workplaces, correctional facilities, senior care facilities. US tuberculosis-outbreak surveillance and prevention programs were built around congregate settings. The Black-patient majority in the outbreak case count sits in the gap between where the outbreaks are happening and where the prevention infrastructure has historically been concentrated.
The setting-shift the surveillance picture shows
For most of the post-World-War-II US tuberculosis-control era, large outbreaks meant jails, homeless shelters, hospitals, and other congregate facilities where unrelated people share air for extended periods. Contact-investigation protocols and TB-program funding flowed to those settings. The Raz team's 2017 to 2023 surveillance picture changes the load-bearing question.
In family-and-social-network outbreaks, transmission moves through the people a patient sees most often: a parent, a sibling, a partner, a coworker who is also a friend, a regular guest in the home. Contact investigation in that setting requires a different mix of skills than congregate-setting investigation: more time per case, more home visits, more language and culturally specific outreach, more trust-building with people who may not be in the formal health-care system. The 4.7-fold Black-disparity in outbreak cases sits inside this mix because the US TB programs investigating these outbreaks have historically been resourced for the congregate-setting model, not the family-and-social-network model.
The MMWR's verbatim conclusion frames the implication tightly: "Maintaining public health capacity for TB outbreak detection, prevention, and response remains essential, even in jurisdictions with low TB incidence." A low national rate does not equal a low risk inside specific community networks; the surveillance picture is doing the work the national rate cannot.
Why earlier detection is the prevention lever
The Raz team documents a second finding that explains where the prevention lever sits. Cases identified through contact investigation showed infectious markers in 23 percent of cases. Cases identified through symptom-driven evaluation, after the patient was already coughing, fever-ridden, or losing weight, showed infectious markers in 61 percent of cases. The difference is roughly three-fold. Earlier intervention through contact investigation catches cases when they are less infectious to the people around them, which means fewer secondary transmissions, smaller outbreaks, and a more manageable downstream caseload.
That is the prevention lever the disparity finding sits next to. If contact investigation in Black family and social networks is under-resourced compared with contact investigation in other settings, the 4.7-fold over-representation continues. If contact investigation in Black family and social networks is well-resourced, with home visits, language-access support, primary-care linkage, and trust-building, the disparity contracts because cases get caught earlier in the transmission chain.
What the peer-reviewed projection adds
A 2024 paper in JAMA Network Open led by Nicole A. Swartwood at Harvard T.H. Chan School of Public Health, with senior authors at the CDC Division of Tuberculosis Elimination, projected the cost and quality-adjusted-life-year consequences of eliminating racial and ethnic disparities in US-born TB incidence and case fatality from 2023 through 2035 (Swartwood et al., JAMA Network Open 2024; PMID 39254977). The cohort included 31,811 US-born persons with reported TB 2010 through 2019, stratified by non-Hispanic American Indian or Alaska Native, non-Hispanic Asian, non-Hispanic Black, Hispanic, non-Hispanic Native Hawaiian or Other Pacific Islander, and non-Hispanic White populations.
Absent intervention, the Swartwood team projects that the existing racial and ethnic disparities persist through 2035. The Raz 2026 MMWR finding that outbreak-driven Black-disparity acceleration is concentrated in 2017 through 2023 family-and-social-network transmission suggests the projection may understate the trajectory. The peer-reviewed projection paper and the MMWR surveillance picture together describe a problem that is documented at population scale and projected forward at policy scale.
The risk-factor pattern in outbreak cases
The Raz team also documented elevated rates of three risk factors in outbreak-associated cases compared with non-outbreak US TB baseline. Substance use was reported in 27 percent of outbreak cases versus 12 percent of non-outbreak cases. Homelessness was reported in 9 percent versus 5 percent. Recent incarceration was reported in 11 percent versus 3 percent.
These three risk factors are documented in the surveillance data; they are not the editorial conclusion. The structural reading the article carries: substance use, homelessness, and recent incarceration are themselves downstream of housing access, primary-care access, criminal-legal-system contact patterns, and the broader Black social-determinant pattern that the cycle-32 state-level Black-mortality framework documents. The 4.7-fold Black over-representation in outbreak cases is not a story about individual risk behavior; it is a story about which communities have historically had the thinnest TB-program contact-investigation coverage and the thinnest primary-care safety nets.
Five voices on the evidence and policy layers
The published evidence base is anchored by Kala M. Raz, MPH (CDC Division of Tuberculosis Elimination, lead author MMWR 75:16); Suzanne M. Marks, MPH, MA (CDC Division of Tuberculosis Elimination, senior author MMWR 75:16 and co-author Swartwood 2024); Terrika Barham, MPH (CDC Office of Health Equity, National Center for HIV, Viral Hepatitis, STD, and TB Prevention, co-author Swartwood 2024); Nicole A. Swartwood, MS (lead author Swartwood 2024 at Harvard T.H. Chan School of Public Health Department of Global Health and Population); and Alexandre White, PhD (Departments of History of Medicine and Sociology at Johns Hopkins University, structural-racism-and-medicine scholar whose work places the current TB-disparity finding inside the longer historical context of TB-and-Black-community-health in the United States).
What the evidence does not yet tell us
Three things the published record does not currently pin down. The MMWR's 23-state geographic distribution is not disaggregated by Black-share at the state or outbreak level; whether the 42 percent Black share is concentrated in specific regions or distributed across the affected states is unclear from the published surveillance data. Whether the 42 percent share differs by US-born versus foreign-born Black populations is similarly not disaggregated; the Swartwood 2024 paper restricts to US-born persons and the MMWR does not break out nativity for outbreak cases. And the CDC TB Statistics annual surveillance report URL was inaccessible at the time of memo preparation, so the most current 2024 US TB incidence rate per 100,000 by race and ethnicity is pending direct retrieval from the CDC TB Statistics annual report PDF.
Three things to ask, depending on who you are
For Black readers who have a household contact, social-network member, or close coworker recently diagnosed with active TB. Ask the TB-program contact investigator who reaches you what specific contact-investigation services are available: tuberculin skin test or interferon-gamma release assay at no cost, home visit by a public-health nurse, treatment for latent tuberculosis infection if the test is positive, and follow-up after the initial encounter. If the program is under-resourced and the contact-investigation visit is rushed or delayed, ask the local health department's TB program director for a follow-up appointment and a written record of what testing was offered. The Raz team's contact-investigation finding shows the difference between catching TB at 23 percent infectious-marker rates (contact-traced) and 61 percent (symptom-driven) is the work of trained TB-program staff with enough time and language-access support to do home visits in the affected social networks.
For Black readers in jurisdictions with low overall TB incidence. A low national or state TB rate does not mean low TB risk inside your own community network. The MMWR's verbatim conclusion makes this explicit: "Maintaining public health capacity for TB outbreak detection, prevention, and response remains essential, even in jurisdictions with low TB incidence." If your state legislator or local health department is considering TB-program funding reductions on the basis of a low overall state TB rate, the MMWR data is the document to point at. Your state's TB-program capacity to do family-and-social-network contact investigation is what the Raz team's data shows is doing the prevention work.
For Black readers in Black-led public-health advocacy or community-health-worker programs. The MMWR's documentation that outbreaks are concentrated in family and social networks rather than congregate settings reframes the operational question. Community health workers embedded in Black social networks, with trust and language-access, are the lever the data supports. Black-led community-health-worker programs at the state and county level are positioned to argue for TB-program contact-investigation funding integrated with their existing networks. The Black Health provider directory lists primary-care clinicians, infectious-disease specialists, and pulmonologists with verified active licenses for readers who want a clinician comfortable with TB testing, latent-TB-infection treatment, and family-network management of TB exposure.
Update plan
We will update this piece when the CDC TB Statistics annual surveillance report for 2024 publishes (typically late spring or early summer), when state-level disaggregation of the MMWR's 42 percent Black share is published, when US-born versus foreign-born Black-disparity disaggregation appears in peer-reviewed analysis, or when state-level TB-program funding reductions or expansions in the affected 23 states are documented.
Citations
- Raz KM, Gwynn LK, Reed M, Fortin K, Doe N, Cain KP, Schwartz NG, Marks SM, Stewart RJ. Large Tuberculosis Outbreaks in the United States, 2017-2023. Morbidity and Mortality Weekly Report. 2026 Apr 30;75(16):205-210. cdc.gov/mmwr/volumes/75/wr/mm7516a1.htm.
- Swartwood NA, Li Y, Regan M, Marks SM, Barham T, et al. Estimated Health and Economic Outcomes of Racial and Ethnic Tuberculosis Disparities in US-Born Persons. JAMA Network Open. 2024. PMID 39254977.
- Springer YP, Filardo TD, Woodruff RS, Self JL. Racial and Ethnic Disaggregation of Tuberculosis Incidence and Risk Factors Among American Indian and Alaska Native Persons-United States, 2001-2020. American Journal of Public Health. 2024. PMID 38335486.
