Survey for tuberculosis in a tribal population in North Arcot District.
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.
Datta
M
M
Tuberculosis Research Centre (Indian Council of Medical Research), Chetput, Chennai, India. manjulad@yahoo.com
Radhamani
M P
MP
Sadacharam
K
K
Selvaraj
R
R
Rao
D L
DL
Rao
R S
RS
Gopalan
B N
BN
Prabhakar
R
R
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
D000995:Antitubercular Agents; D001500:BCG Vaccine