title: Can BCG-vaccinated children be included in tuberculin surveys to estimate the annual risk of tuberculous infection in India?
abstract: METHODS
  Selected villages in three defined zones of India.
  
  
  OBJECTIVE
  To compare the estimated prevalence of tuberculous infection among children with and without bacille Calmette-Guérin (BCG) scar.
  
  
  METHODS
  During a nationwide tuberculin survey, 1-9-year-old children were tuberculin tested using 1TU-PPD RT23 with Tween 80.
  
  
  RESULTS
  In the 5-9 year age group, subgroups of tuberculous infected children could be seen as distinct humps among those with or without BCG scar, but not in those aged 1-4 years. In children aged 1-4 years, the estimated prevalence of infection was respectively 3.5%, 3.8% and 3.6% among children without BCG scar, and 4.8%, 4.7% and 4.5% among children with BCG scar in the western, northern and eastern zones. In those aged 5-9 years, the estimated prevalence was respectively 10.4%, 11.0% and 9.1% among children without BCG scar and 11%, 11.9% and 8.7% among children with BCG scar in the three zones. Thus, in children aged 1-4 years, the estimated prevalence among those with BCG scar was considerably higher than in those without BCG scar. This difference was small in those aged 5-9 years.
  
  
  CONCLUSIONS
  Tuberculin surveys may be conducted irrespective of BCG scar status among children aged 5-9 years, when BCG vaccination is given using Danish 1331 strain during infancy under the Expanded Program of Immunization.
authors.affiliation: National Tuberculosis Institute, Bangalore, Karnataka, India. vin_chadha@rediffmail.com
authors.forename: V K
authors.initials: VK
authors.lastname: Chadha
authors.forename: P S
authors.initials: PS
authors.lastname: Jagannatha
authors.forename: P
authors.initials: P
authors.lastname: Kumar
mesh_terms: D017677:Age Distribution; D001500:BCG Vaccine / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D003625:Data Collection; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D015995:Prevalence; D018570:Risk Assessment; D014374:Tuberculin Test / Q000706:statistics & numerical data*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control*
chemical_list: D001500:BCG Vaccine