Tuberculosis Genotype Clusters and Transmission in the U.S., 2009–2018


      In the U.S., universal genotyping of culture-confirmed tuberculosis cases facilitates cluster detection. Early recognition of the small clusters more likely to become outbreaks can help prioritize public health resources for immediate interventions.


      This study used national surveillance data reported during 2009–2018 to describe incident clusters (≥3 tuberculosis cases with matching genotypes not previously reported in the same county); data were analyzed during 2020. Cox proportional hazards regression models were used to examine the patient characteristics associated with clusters doubling in size to ≥6 cases.


      During 2009–2018, a total of 1,516 incident clusters (comprising 6,577 cases) occurred in 47 U.S. states; 231 clusters had ≥6 cases. Clusters of ≥6 cases disproportionately included patients who used substances, who had recently experienced homelessness, who were incarcerated, who were U.S. born, or who self-identified as being of American Indian or Alaska Native race or of Black race. A median of 54 months elapsed between the first and the third cases in clusters that remained at 3–5 cases compared with a median of 9.5 months in clusters that grew to ≥6 cases. The longer time between the first and third cases and the presence of ≥1 patient aged ≥65 years among the first 3 cases predicted a lower hazard for accumulating ≥6 cases.


      Clusters accumulating ≥3 cases within a year should be prioritized for intervention. Effective response strategies should include plans for targeted outreach to U.S.-born individuals, incarcerated people, those experiencing homelessness, people using substances, and individuals self-identifying as being of American Indian or Alaska Native race or of Black race.
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to American Journal of Preventive Medicine
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Mindra G
        • Wortham JM
        • Haddad MB
        • Powell KM.
        Tuberculosis outbreaks in the United States, 2009-2015.
        Public Health Rep. 2017; 132: 157-163
        • National Tuberculosis Controllers Association, Centers for Disease Control and Prevention (CDC)
        Guidelines for the investigation of contacts of persons with infectious tuberculosis.
        MMWR Recomm Rep. 2005; 54: 1-47
        • Ghosh S
        • Moonan PK
        • Cowan L
        • Grant J
        • Kammerer S
        • Navin TR.
        Tuberculosis genotyping information management system: enhancing tuberculosis surveillance in the United States.
        Infect Genet Evol. 2012; 12: 782-788
        • Centers for Disease Control and Prevention
        Prioritizing tuberculosis genotype clusters for further investigation & public health action.
        HHS, Centers for Disease Control and Prevention, Atlanta, GAAugust 2017 (Published)
        • Althomsons SP
        • Kammerer JS
        • Shang N
        • Navin TR.
        Using routinely reported tuberculosis genotyping and surveillance data to predict tuberculosis outbreaks.
        PLoS One. 2012; 7: e48754
      1. Reported tuberculosis in the United States, 2018: Table 1. Tuberculosis cases, case rates per 100,000 population, deaths, and death rates per 100,000 population, and percent change: United States, 1953–2018.
        Centers for Disease Control and Prevention, September 6, 2019 (Updated)
        • Teeter LD
        • Kammerer JS
        • Ghosh S
        • et al.
        Evaluation of 24-locus MIRU-VNTR genotyping in Mycobacterium tuberculosis cluster investigations in four jurisdictions in the United States, 2006–2010.
        Tuberculosis (Edinb). 2017; 106: 9-15
      2. CDC tuberculosis surveillance data training - report of verified case of tuberculosis.
        Centers for Disease Control and Prevention, September 1, 2012 (Updated)
      3. Rural-urban continuum codes. U.S. Department of Agriculture. Economic Research Service. Updated December 10, 2020. Accessed December 31, 2020.

      4. Targeted tuberculin testing and treatment of latent tuberculosis infection.
        MMWR Recomm Rep. 2000; 49: 1-51
        • Yuen CM
        • Kammerer JS
        • Marks K
        • Navin TR
        • France AM.
        Recent transmission of tuberculosis - United States, 2011-2014.
        PLoS One. 2016; 11e0153728
        • Kammerer JS
        • Shang N
        • Althomsons SP
        • Haddad MB
        • Grant J
        • Navin TR.
        Using statistical methods and genotyping to detect tuberculosis outbreaks.
        Int J Health Geogr. 2013; 12: 15
        • Munn MS
        • Duchin JS
        • Kay M
        • Pecha M
        • Thibault CS
        • Narita M.
        Analysis of risk factors for tuberculous infection following exposure at a homeless shelter.
        Int J Tuberc Lung Dis. 2015; 19: 570-575
        • Lofy KH
        • McElroy PD
        • Lake L
        • et al.
        Outbreak of tuberculosis in a homeless population involving multiple sites of transmission.
        Int J Tuberc Lung Dis. 2006; 10: 683-689
        • Centers for Disease Control and Prevention (CDC)
        Tuberculosis outbreak associated with a homeless shelter - Kane County, Illinois, 2007-2011.
        MMWR Morb Mortal Wkly Rep. 2012; 61: 186-189
        • Powell KM
        • VanderEnde DS
        • Holland DP
        • et al.
        Outbreak of drug-resistant Mycobacterium tuberculosis among homeless people in Atlanta, Georgia, 2008-2015.
        Public Health Rep. 2017; 132: 231-240
        • Centers for Disease Control and Prevention (CDC)
        Notes from the field: tuberculosis cluster associated with homelessness–Duval County, Florida, 2004-2012.
        MMWR Morb Mortal Wkly Rep. 2012; 61: 539-540
        • Wille SM
        • Kemp KA
        • Greenfield BL
        • Walls ML.
        Barriers to healthcare for American Indians experiencing homelessness.
        J Soc Distress Homeless. 2017; 26: 1-8
        • Volkmann T
        • Moonan PK
        • Miramontes R
        • Oeltmann JE.
        Excess alcohol use and death among tuberculosis patients in the United States, 1997-2012.
        J Tuberc Res. 2016; 4: 18-22
        • Oeltmann JE
        • Kammerer JS
        • Pevzner ES
        • Moonan PK.
        Tuberculosis and substance abuse in the United States, 1997-2006.
        Arch Intern Med. 2009; 169: 189-197
        • Winston CA
        • Menzies HJ.
        Pediatric and adolescent tuberculosis in the United States, 2008–2010.
        Pediatrics. 2012; 130: e1425-e1432
        • Hamblion EL
        • Le Menach A
        • Anderson LF
        • et al.
        Recent TB transmission, clustering and predictors of large clusters in London, 2010–2012: results from first 3 years of universal MIRU-VNTR strain typing.
        Thorax. 2016; 71: 749-756
        • Izumi K
        • Murase Y
        • Uchimura K
        • et al.
        Transmission of tuberculosis and predictors of large clusters within three years in an urban setting in Tokyo, Japan: a population-based molecular epidemiological study.
        BMJ Open. 2019; 9e029295
      5. Essential components of a tuberculosis prevention and control program.
        MMWR Recomm Rep. 1995; 44: 1-16