title: Mycobacterium Tuberculosis Infection, Immigration Status, and Diagnostic Discordance: A Comparison of Tuberculin Skin Test and QuantiFERON-TB Gold In-Tube Test Among Immigrants to the U.S.
abstract: OBJECTIVE
  We used a recent source of nationally representative population data on tuberculosis (TB) infection to characterize concordance between the tuberculin skin test (TST) and the QuantiFERON-TB Gold In-Tube (QFT-GIT) blood test for immigrants in the United States.
  
  
  METHODS
  We used TB screening data from the 2011-2012 National Health and Nutrition Examination Survey to examine concordance between the TST and QFT-GIT--an interferon-gamma release assay (IGRA) blood test--for 7,097 U.S. natives, naturalized citizens, and noncitizens.
  
  
  RESULTS
  Consistent with prior findings, one in five immigrants in the survey was identified with latent TB infection (LTBI), a rate 14 times higher than for U.S. natives. We also found higher rates of discordant TST/IGRA results among immigrants than among U.S. natives. Unadjusted discordance between TST and IGRA was 3% among U.S. natives (weighted N=5,684,274 of 191,179,213) but ranged up to 19% for noncitizens (weighted N=3,722,960 of 19,377,147). Adjusting for age, sex, and race/ethnicity, noncitizens had more than nine times the odds of having a positive TST result but negative QFT-GIT result compared with U.S. natives.
  
  
  CONCLUSIONS
  Our findings suggest that whether and how either of these tests should be deployed is highly context sensitive. Significant discordance in test results when used among immigrants raises the possibility of missed opportunities for harm reduction in this already at-risk population. However, we found little distinction between the tests in terms of diagnostic outcome when used in a U.S. native population, suggesting little benefit to the adoption and use of the QFT-GIT test in place of TST on the basis of test performance alone for this population.
authors.affiliation: University of Nebraska Medical Center, Department of Health Services Research and Administration, Omaha, NE.
authors.forename: Fernando A
authors.initials: FA
authors.lastname: Wilson
authors.affiliation: University of North Texas Health Science Center, Department of Health Management and Policy, Fort Worth, TX.
authors.forename: Thaddeus L
authors.initials: TL
authors.lastname: Miller
authors.affiliation: City University of New York, New York, NY.
authors.forename: Jim P
authors.initials: JP
authors.lastname: Stimpson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D002648:Child; D003365:Costs and Cost Analysis; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D059425:Interferon-gamma Release Tests / Q000191:economics / Q000706:statistics & numerical data*; D055985:Latent Tuberculosis / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology*; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000191:economics / Q000379:methods / Q000592:standards; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D009749:Nutrition Surveys; D013902:Radiography, Thoracic; D012680:Sensitivity and Specificity; D014374:Tuberculin Test / Q000191:economics / Q000706:statistics & numerical data*; D014397:Tuberculosis, Pulmonary / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000276:immunology*; D014481:United States; D055815:Young Adult