title: Tuberculosis screening by tuberculosis skin test or QuantiFERON-TB Gold In-Tube Assay among an immigrant population with a high prevalence of tuberculosis and BCG vaccination.
abstract: BACKGROUND
  Each year 1 million persons acquire permanent U.S. residency visas after tuberculosis (TB) screening. Most applicants undergo a 2-stage screening with tuberculin skin test (TST) followed by CXR only if TST-positive at > 5 mm. Due to cross reaction with bacillus Calmette-Guérin (BCG), TST may yield false positive results in BCG-vaccinated persons. Interferon gamma release assays exclude antigens found in BCG. In Vietnam, like most high TB-prevalence countries, there is universal BCG vaccination at birth.
  
  
  OBJECTIVE
  1. Compare the sensitivity of QuantiFERON-TB Gold In-Tube Assay (QFT) and TST for culture-positive pulmonary TB. 2. Compare the age-specific and overall prevalence of positive TST and QFT among applicants with normal and abnormal CXR.
  
  
  METHODS
  We obtained TST and QFT results on 996 applicants with abnormal CXR, of whom 132 had TB, and 479 with normal CXR.
  
  
  RESULTS
  The sensitivity for tuberculosis was 86.4% for QFT; 89.4%, 81.1%, and 52.3% for TST at 5, 10, and 15 mm. The estimated prevalence of positive results at age 15-19 years was 22% and 42% for QFT and TST at 10 mm, respectively. The prevalence increased thereafter by 0.7% year of age for TST and 2.1% for QFT, the latter being more consistent with the increase in TB among applicants.
  
  
  CONCLUSIONS
  During 2-stage screening, QFT is as sensitive as TST in detecting TB with fewer requiring CXR and being diagnosed with LTBI. These data support the use of QFT over TST in this population.
authors.affiliation: National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: John A
authors.initials: JA
authors.lastname: Painter
authors.affiliation: The Methodist Hospital Research Institute, Houston, Texas, United States of America.
authors.forename: Edward A
authors.initials: EA
authors.lastname: Graviss
authors.affiliation: Cho Ray Hospital, Visa Medical Unit, Ho Chi Minh City, Vietnam.
authors.forename: Hoang Hoa
authors.initials: HH
authors.lastname: Hai
authors.affiliation: Cho Ray Hospital, Visa Medical Unit, Ho Chi Minh City, Vietnam.
authors.forename: Duong Thi Cam
authors.initials: DT
authors.lastname: Nhung
authors.affiliation: Cho Ray Hospital, Visa Medical Unit, Ho Chi Minh City, Vietnam.
authors.forename: Tran Thi Thanh
authors.initials: TT
authors.lastname: Nga
authors.affiliation: The Methodist Hospital Research Institute, Houston, Texas, United States of America.
authors.forename: Ngan P
authors.initials: NP
authors.lastname: Ha
authors.affiliation: Denver Health and Hospital Authority, Denver, Colorado, United States of America.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Wall
authors.affiliation: Cho Ray Hospital, Visa Medical Unit, Ho Chi Minh City, Vietnam.
authors.forename: Le Thien Huong
authors.initials: le TH
authors.lastname: Loan
authors.affiliation: Denver Health and Hospital Authority, Denver, Colorado, United States of America.
authors.forename: Matt
authors.initials: M
authors.lastname: Parker
authors.affiliation: National Center for HIV, Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Lilia
authors.initials: L
authors.lastname: Manangan
authors.affiliation: Foundation for Innovative New Diagnostics, Geneva, Switzerland.
authors.forename: Rick
authors.initials: R
authors.lastname: O'Brien
authors.affiliation: Center for Global Health, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Maloney
authors.affiliation: Biostatistics and Information Management Office, Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: R M
authors.initials: RM
authors.lastname: Hoekstra
authors.affiliation: Denver Health and Hospital Authority, Denver, Colorado, United States of America.
authors.forename: Randall
authors.initials: R
authors.lastname: Reves
mesh_terms: D000293:Adolescent; D000328:Adult; D001500:BCG Vaccine / Q000627:therapeutic use*; D054242:Emigrants and Immigrants; D005260:Female; D006801:Humans; D008297:Male; D012680:Sensitivity and Specificity; D012882:Skin Tests / Q000379:methods*; D014376:Tuberculosis / Q000175:diagnosis* / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D001500:BCG Vaccine