title: Survey for tuberculosis in a tribal population in North Arcot District.
abstract: METHODS
  Tribal villages in the jungles of the Jawadhu hills, South India.
  
  
  OBJECTIVE
  To estimate the prevalence of tuberculosis (TB) infection and disease in a remote tribal population.
  
  
  METHODS
  A cross-sectional survey with two-stage screening for identification of cases. A stratified probability proportional sample with the hamlet as the unit.
  
  
  METHODS
  Among 56 revenue divisions with a population of about 66,000, 24 revenue divisions were selected. Among 26,320 persons registered, children < 10 years were tuberculin tested and reactions were read after 72 hours. Those over 15 were X-rayed, and tuberculosis symptoms were investigated. Sputum was collected from those with abnormal X-ray or symptoms and examined for smear and culture positivity and sensitivity.
  
  
  RESULTS
  Of the 6952 children tested and read, 5% had BCG scars and the prevalence of infection was 5%. The annual risk of infection was 1.1. Among adults, the prevalence of bacillary cases was 8/1000 and X-ray cases 29/1000. The prevalence of bacillary disease was higher among males, particularly with increasing age. Thirty symptomatic cases had normal X-rays and 63 X-ray cases had no symptoms. Thus prevalence would have been underestimated if either method had been used alone for screening. Isoniazid resistance was seen in 12% of patients, two of whom also had rifampicin resistance (2.6%).
  
  
  CONCLUSIONS
  The prevalence and pattern of tuberculosis in this tribal group is similar to that observed in non-tribal areas.
authors.affiliation: Tuberculosis Research Centre (Indian Council of Medical Research), Chetput, Chennai, India. manjulad@yahoo.com
authors.forename: M
authors.initials: M
authors.lastname: Datta
authors.forename: M P
authors.initials: MP
authors.lastname: Radhamani
authors.forename: K
authors.initials: K
authors.lastname: Sadacharam
authors.forename: R
authors.initials: R
authors.lastname: Selvaraj
authors.forename: D L
authors.initials: DL
authors.lastname: Rao
authors.forename: R S
authors.initials: RS
authors.lastname: Rao
authors.forename: B N
authors.initials: BN
authors.lastname: Gopalan
authors.forename: R
authors.initials: R
authors.lastname: Prabhakar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000995:Antitubercular Agents / Q000494:pharmacology; D001500:BCG Vaccine; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D008297:Male; D008400:Mass Chest X-Ray; D008403:Mass Screening; D008826:Microbial Sensitivity Tests; D015995:Prevalence; D012424:Rural Population; D012494:Sampling Studies; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control
chemical_list: D000995:Antitubercular Agents; D001500:BCG Vaccine