Trends in the annual risk of tuberculous infection in India

Int J Tuberc Lung Dis. 2013 Mar;17(3):312-9. doi: 10.5588/ijtld.12.0330. Epub 2013 Jan 14.

Abstract

Setting: Twenty-four districts in India.

Objectives: To evaluate trends in annual risk of tuberculous infection (ARTI) in each of four geographically defined zones in the country.

Study design: Two rounds of house-based tuberculin surveys were conducted 8-9 years apart among children aged 1-9 years in statistically selected clusters during 2000-2003 and 2009-2010 (Surveys I and II). Altogether, 184,992 children were tested with 1 tuberculin unit (TU) of purified protein derivative (PPD) RT23 with Tween 80 in Survey I and 69,496 children with 2TU dose of PPD in Survey II. The maximum transverse diameter of induration was measured about 72 h after test administration. ARTI was computed from the prevalence of infection estimated using the mirror-image method.

Results: Estimated ARTI rates in different zones varied between 1.1% and 1.9% in Survey I and 0.6% and 1.2% in Survey II. The ARTI declined by respectively 6.1% and 11.7% per year in the north and west zones; no decline was observed in the south and east zones. National level estimates were respectively 1.5% and 1.0%, with a decline of 4.5% per year in the intervening period.

Conclusion: Although a decline in ARTI was observed in two of the four zones and at national level, the current ARTI of about 1% in three zones suggests that further intensification of TB control activities is required.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antitubercular Agents / therapeutic use
  • BCG Vaccine / administration & dosage
  • Chi-Square Distribution
  • Child
  • Child, Preschool
  • Cluster Analysis
  • Communicable Disease Control / methods
  • Health Surveys
  • Humans
  • India / epidemiology
  • Infant
  • Predictive Value of Tests
  • Prevalence
  • Risk Assessment
  • Risk Factors
  • Rural Health
  • Time Factors
  • Tuberculin Test
  • Tuberculosis / diagnosis
  • Tuberculosis / epidemiology*
  • Tuberculosis / prevention & control
  • Urban Health

Substances

  • Antitubercular Agents
  • BCG Vaccine