title: First national tuberculin survey in Nepal.
abstract: METHODS
  The size of the tuberculosis (TB) problem in Nepal is unknown, as no national tuberculin or TB prevalence survey has yet been performed.
  
  
  OBJECTIVE
  To assess the prevalence of TB infection and the annual risk of TB infection (ARTI) in primary schoolchildren in the three ecological zones (mountains, hills and terai) and Kathmandu valley.
  
  
  METHODS
  A representative sample of primary schoolchildren were tuberculin skin tested using the Mantoux method. The data were analysed using cut-off levels to define infection and by the mirror method.
  
  
  RESULTS
  Of 19577 children registered, 17260 (88.2%) were available for analysis. Seventy-eight per cent had a visible bacille Calmette-Guérin scar. The best estimate of the prevalence of TB infection was 7.0% (95%CI 4.2-9.7), with an ARTI of 0.86% (95%CI 0.49-1.23) using the mirror method, with a mode at 16 mm. Although the ARTI was higher in Kathmandu and the mountains compared to the hills and terai, the difference between the areas was not significant.
  
  
  CONCLUSIONS
  The ARTI in Nepal is lower than previous estimates, indicating a decrease in transmission or overestimation of previous estimates. To obtain information about the trend of the ARTI in Nepal, the survey needs to be repeated in 5 to 7 years.
authors.affiliation: National Tuberculosis Centre, Kathmandu, Nepal.
authors.forename: K B
authors.initials: KB
authors.lastname: Shrestha
authors.forename: P
authors.initials: P
authors.lastname: Malla
authors.forename: K K
authors.initials: KK
authors.lastname: Jha
authors.forename: T M
authors.initials: TM
authors.lastname: Shakya
authors.forename: M
authors.initials: M
authors.lastname: Akhtar
authors.forename: C
authors.initials: C
authors.lastname: Gunneberg
authors.forename: M J
authors.initials: MJ
authors.lastname: van der Werf
mesh_terms: D002648:Child; D006306:Health Surveys; D006801:Humans; D009390:Nepal / Q000453:epidemiology; D014374:Tuberculin Test; D014376:Tuberculosis / Q000175:diagnosis / Q000453:epidemiology*