title: Estimating the burden of tuberculosis among foreign-born persons acquired prior to entering the U.S., 2005-2009.
abstract: BACKGROUND
  The true burden of reactivation of remote latent tuberculosis infection (reactivation TB) among foreign-born persons with tuberculosis (TB) within the United States is not known. Our study objectives were to estimate the proportion of foreign-born persons with TB due reactivation TB and to describe characteristics of foreign-born persons with reactivation TB.
  
  
  METHODS
  We conducted a cross-sectional study of patients with an M. tuberculosis isolate genotyped by the U.S. National TB Genotyping Service, 2005-2009. TB cases were attributed to reactivation TB if they were not a member of a localized cluster of cases. Localized clusters were determined by a spatial scan statistic of cases with isolates with matching TB genotype results. Crude odds ratios and 95% confidence intervals were used to assess relations between reactivation TB and select factors among foreign-born persons.
  
  
  RESULTS
  Among the 36,860 cases with genotyping and surveillance data reported, 22,151 (60%) were foreign-born. Among foreign-born persons with TB, 18,540 (83.7%) were attributed to reactivation TB. Reactivation TB among foreign-born persons was associated with increasing age at arrival, incidence of TB in the country of origin, and decreased time in the U.S. at the time of TB diagnosis.
  
  
  CONCLUSIONS
  Four out of five TB cases among foreign-born persons can be attributed to reactivation TB and present the largest challenge to TB elimination in the U.S. TB control strategies among foreign-born persons should focus on finding and treating latent tuberculosis infection prior to or shortly after arrival to the United States and on reducing the burden of LTBI through improvements in global TB control.
authors.affiliation: Division of Tuberculosis Elimination, United States Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Philip M
authors.initials: PM
authors.lastname: Ricks
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Cain
authors.forename: John E
authors.initials: JE
authors.lastname: Oeltmann
authors.forename: J Steve
authors.initials: JS
authors.lastname: Kammerer
authors.forename: Patrick K
authors.initials: PK
authors.lastname: Moonan
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002648:Child; D002675:Child, Preschool; D017281:Cost of Illness; D004641:Emigration and Immigration / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D013997:Time Factors; D014376:Tuberculosis / Q000175:diagnosis / Q000453:epidemiology* / Q000635:transmission; D014481:United States / Q000453:epidemiology