title: Trend in annual risk of tuberculous infection in north India.
abstract: METHODS
  Six selected districts in Northern India.
  
  
  OBJECTIVE
  To find out the trend in Annual risk of tuberculous infection (ARTI) in north India.
  
  
  METHODS
  Two rounds of community level surveys were conducted during 2000-2001 and 2009-10 respectively. Representative samples of children 1-9 years of age were tuberculin tested and maximum transverse diameter of induration was recorded in mm at about 72 hours. ARTI was computed from the estimated Prevalence of infection using mirror-image technique and anti-mode method.
  
  
  RESULTS
  ARTI was found to decline from 1.9% (confidence interval: 1.7-2.1) at round I to 1.1% (confidence interval: 0.8-1.3) at round II at the rate of 8% per year during the intervening period.
  
  
  CONCLUSIONS
  A significant reduction in the risk of tuberculous infection among children was observed between two rounds of surveys carried out at an interval of about 9 years.
authors.affiliation: Director's Office, New Delhi Tuberculosis Center, New Delhi, India. chopra_drkk@yahoo.co.in
authors.forename: Kamal
authors.initials: K
authors.lastname: Chopra
authors.forename: Vineet K
authors.initials: VK
authors.lastname: Chadha
authors.forename: Jitendra
authors.initials: J
authors.lastname: Ramachandra
authors.forename: Nishi
authors.initials: N
authors.lastname: Aggarwal
mesh_terms: D001500:BCG Vaccine / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D008297:Male; D009169:Mycobacterium tuberculosis / Q000472:pathogenicity*; D011159:Population Surveillance; D015995:Prevalence; D018570:Risk Assessment; D014376:Tuberculosis / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control
chemical_list: D001500:BCG Vaccine