Yield of testing and treatment for tuberculosis among foreign-born persons during contact investigations in the United States: A semi-systematic review

PLoS One. 2018 Jul 19;13(7):e0200485. doi: 10.1371/journal.pone.0200485. eCollection 2018.


Background: Contact investigation is an important strategy for maintaining control of tuberculosis (TB) in the United States. However, testing and treatment outcomes specifically to foreign-born populations are poorly understood. We reviewed literature on testing and LTBI identified during contact investigations in foreign-born populations living in the US.

Methods: We conducted a comprehensive search of peer-reviewed and grey literature using Cochrane systematic review methods. We included studies with adult and adolescent populations that were at least 50% foreign-born. Pooled proportions and 95% confidence intervals (CIs) were calculated via inverse-variance weighted meta-analysis, and cumulative proportions were calculated as products of adjacent step proportions.

Results: We identified 22 studies published between 1997 and 2014 that included at least 50% foreign-born participants. From studies of predominantly (>90%) foreign-born populations, almost all identified contacts were recruited and had valid test results, and 54.8% (95% CI 45.1-62.5%) of contacts with valid test results tested positive. From studies of majority (50% to 90%) foreign-born populations, 78.4% (95% CI 78.0-78.9%) of identified contacts were recruited, 92.0% (95% CI 91.6-92.3%) of recruited contacts had valid test results, and 38.5% (95% CI 31.9%-44.2%) of persons with valid results tested positive. These proportions varied by test type in studies of predominantly foreign-born populations. For every 1000 contacts identified in predominantly foreign-born populations, we estimate that 535 (95% CI 438 to 625) will test positive, and 354 (95% CI 244 to 453) will complete LTBI treatment. For every 1000 contacts identified in majority foreign-born populations, these estimates are 276 (95% CI 230 to 318), and 134 (95% CI 44 to 264), respectively.

Conclusions: Contact investigation is a high yield activity for identifying and treating foreign-born persons with LTBI, but must be complemented by other tuberculosis control activities in order to achieve continued progress toward TB elimination.

Publication types

  • Research Support, U.S. Gov't, P.H.S.
  • Systematic Review

MeSH terms

  • Adolescent
  • Adult
  • Communicable Disease Control / methods
  • Communicable Disease Control / statistics & numerical data*
  • Diagnostic Tests, Routine
  • Emigrants and Immigrants / statistics & numerical data*
  • Humans
  • Latent Tuberculosis / diagnosis*
  • Latent Tuberculosis / ethnology
  • Latent Tuberculosis / therapy*
  • Population Surveillance / methods
  • United States / epidemiology

Grant support

This research was supported by the National Center for HIV, Viral Hepatitis, STD, and TB Prevention Epidemiologic and Economic Modeling Agreement (https://www.cdc.gov/nchhstp/default.htm), cooperative agreement #5U38PS004649, to principal investigator JGK. Funding for this study was via a cooperative agreement, which means that the funder was actively involved in research design and manuscript preparation, and one of our co-authors (SM) is an employee of the funding agency. No additional external funding was received for this study.