title: Latent tuberculous infection prevalence among paediatric contacts of drug-resistant and drug-susceptible cases.
abstract: METHODS
  Tuberculosis (TB) clinic in Tijuana, México.
  
  
  BACKGROUND
  Tuberculin conversion rates in contacts of drug-resistant cases have been reported to be lower than among contacts of drug-susceptible cases.
  
  
  OBJECTIVE
  To determine if the prevalence of latent tuberculous infection (LTBI) among paediatric contacts of drug-resistant cases is lower than that of contacts of drug-susceptible cases.
  
  
  METHODS
  In a cross-sectional study, LTBI among paediatric contacts of culture-proven TB cases was evaluated using the tuberculin skin test and interferon-gamma release assay. Rates among contacts of drug-susceptible and drug-resistant cases were compared.
  
  
  RESULTS
  The TST was positive in 83.1% of the drug-susceptible group vs. 76.0% for the drug-resistant group (P = 0.25). Using the QuantiFERON Gold In-Tube (QFT-GIT) assay, drug-resistant cases had a higher rate of positivity than the drug-susceptible group, although this difference did not reach statistical significance (42.3% positivity among drug-susceptible cases vs. 57.7% among drug-resistant cases; P = 0.48).
  
  
  CONCLUSIONS
  The proportion of LTBI is similar among paediatric contacts, regardless of whether the index case is drug-resistant or -susceptible.
authors.affiliation: Clínica de Tuberculosis, Hospital General Tijuana, Tijuana, Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Laniado-Laborín
authors.affiliation: Clínica de Tuberculosis, Hospital General Tijuana, Tijuana, Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Cazares-Adame
authors.affiliation: Clínica de Tuberculosis, Hospital General Tijuana, Tijuana, Mexico.
authors.forename: M-L
authors.initials: ML
authors.lastname: Volker-Soberanes
authors.affiliation: Clínica de Tuberculosis, Hospital General Tijuana, Tijuana, Mexico.
authors.forename: C
authors.initials: C
authors.lastname: del Portillo-Mustieles
authors.affiliation: Clínica de Tuberculosis, Hospital General Tijuana, Tijuana, Mexico.
authors.forename: C
authors.initials: C
authors.lastname: Villa-Rosas
authors.affiliation: Clínica de Tuberculosis, Hospital General Tijuana, Tijuana, Mexico.
authors.forename: L
authors.initials: L
authors.lastname: Oceguera-Palao
authors.affiliation: Clínica de Tuberculosis, Hospital General Tijuana, Tijuana, Mexico.
authors.forename: J
authors.initials: J
authors.lastname: Magallanes-Mijares
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000995:Antitubercular Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D016358:Contact Tracing; D003430:Cross-Sectional Studies; D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007223:Infant; D059425:Interferon-gamma Release Tests; D055985:Latent Tuberculosis / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology* / Q000635:transmission*; D008297:Male; D008800:Mexico / Q000453:epidemiology; D011237:Predictive Value of Tests; D015995:Prevalence; D014374:Tuberculin Test; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology* / Q000635:transmission*
chemical_list: D000995:Antitubercular Agents