title: Prevalence and risk factors for transmission of infection among children in household contact with adults having pulmonary tuberculosis.
abstract: OBJECTIVE
  To study the prevalence of tuberculosis infection among children in household contact with adults having pulmonary tuberculosis, and identify the possible risk factors.
  
  
  METHODS
  Children under the age of 5 years who were in household contact with 200 consecutive adults with pulmonary tuberculosis underwent tuberculin skin testing. Transverse induration of greater than 10 mm was defined as positive tuberculin test suggestive of tubercular infection. Infected children underwent chest radiography and analysis of gastric lavage fluid or induced sputum for detection of acid fast bacilli.
  
  
  RESULTS
  Tuberculin test was positive in 95 of 281 contacts (33.8%), of which 65 were contacts of sputum positive patients, while 30 were contacts of sputum negative patients. Nine of these children were diagnosed as having tuberculosis based on clinical features and/or recovery of acid fast bacilli; seven were in contact with sputum positive adults. The important risk factors for transmission of infection were younger age, severe malnutrition, absence of BCG vaccination, contact with an adult who was sputum positive, and exposure to environmental tobacco smoke.
  
  
  CONCLUSIONS
  The prevalence of tuberculosis infection and clinical disease among children in household contact with adult patients is higher than in the general population, and risk is significantly increased by contact with sputum positive adults.
authors.affiliation: Department of Pediatrics, Postgraduate Institute of Medical Education and Research, Chandigarh, India. meenusingh4@rediffmail.com
authors.forename: M
authors.initials: M
authors.lastname: Singh
authors.forename: M L
authors.initials: ML
authors.lastname: Mynak
authors.forename: L
authors.initials: L
authors.lastname: Kumar
authors.forename: J L
authors.initials: JL
authors.lastname: Mathew
authors.forename: S K
authors.initials: SK
authors.lastname: Jindal
mesh_terms: D000328:Adult; D000367:Age Factors; D001500:BCG Vaccine; D002675:Child, Preschool; D005192:Family Health; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D044342:Malnutrition / Q000150:complications; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D012307:Risk Factors; D013183:Sputum / Q000382:microbiology; D014028:Tobacco Smoke Pollution / Q000009:adverse effects; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000635:transmission*
chemical_list: D001500:BCG Vaccine; D014028:Tobacco Smoke Pollution