title: A baseline survey of the prevalence of tuberculosis in a community in south India at the commencement of a DOTS programme.
abstract: OBJECTIVE
  To determine the baseline prevalence of culture-positive and smear-positive tuberculosis and the annual risk of tuberculous infection (ARTI) in a community in south India where DOTS is being implemented.
  
  
  METHODS
  Using cluster sampling, 50 rural panchayats (villages) and three urban units in Tiruvallur district were selected randomly. All adults aged > or = 15 years underwent symptom and radiographic examination, and those with abnormal shadows and/or chest symptoms had sputum smear and culture examination. In another cluster sample of 73 villages and three urban units, all children aged < 10 years were tuberculin tested.
  
  
  RESULTS
  The prevalence of culture-positive and smear-positive tuberculosis was respectively 605 and 323/100,000. Both increased appreciably with age, and were substantially higher in males than in females at all ages; the overall male:female ratio was 5.5 for culture-positive and 6.5 for smear-positive tuberculosis. The ARTI in children aged under 10 years was 1.6%, and was unaffected by sex. Over three decades there was an overall decline of 1.8% per annum in the prevalence of culture-positive and 2.1% for smear-positive tuberculosis.
  
  
  CONCLUSIONS
  Tuberculosis is a major problem in this rural community in south India, with a prevalence of 605/100,000 for culture-positive tuberculosis and 323/100,000 for smear-positive tuberculosis.
authors.affiliation: Tuberculosis Research Centre, Chetput, Chennai, India.
authors.forename: P G
authors.initials: PG
authors.lastname: Gopi
authors.forename: R
authors.initials: R
authors.lastname: Subramani
authors.forename: S
authors.initials: S
authors.lastname: Radhakrishna
authors.forename: C
authors.initials: C
authors.lastname: Kolappan
authors.forename: K
authors.initials: K
authors.lastname: Sadacharam
authors.forename: T S
authors.initials: TS
authors.lastname: Devi
authors.forename: T R
authors.initials: TR
authors.lastname: Frieden
authors.forename: P R
authors.initials: PR
authors.lastname: Narayanan
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D016000:Cluster Analysis; D003625:Data Collection; D003906:Developing Countries; D023801:Directly Observed Therapy / Q000592:standards* / Q000639:trends; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012111:Residence Characteristics; D018570:Risk Assessment; D012424:Rural Population; D017678:Sex Distribution; D013183:Sputum / Q000382:microbiology; D016019:Survival Analysis; D014374:Tuberculin Test; D014376:Tuberculosis / Q000175:diagnosis* / Q000453:epidemiology*; D014505:Urban Population