The annual risk of tuberculous infection in the eastern zone of India.
METHODS
Rural and urban areas of eight selected districts in the eastern zone of India.


OBJECTIVE
To estimate the annual risk of tuberculous infection (ARTI).


METHODS
A community-based, cross-sectional tuberculin survey was conducted among children aged 1-9 years residing in a sample of rural and urban areas. Stratified two-stage cluster sampling was adopted for selection of rural and urban clusters. A total of 40964 children in 515 clusters underwent tuberculin testing and reading with 1TU PPD RT23 with Tween 80; the maximum transverse diameter of induration was measured about 72 h after the test.


RESULTS
A bacille Calmette-Gúerin (BCG) scar was observed in 51.5% of the test-read children. The frequency distribution of tuberculin reaction size among 19332 children without BCG scar was found to be bimodal, with the mode of reactions attributable to infection with tubercle bacilli at 20 mm. The prevalence of infection was estimated as 6.9%. The ARTI computed from the estimated prevalence was 1.3%. Children residing in the urban areas were found to be at a significantly higher risk of infection than those residing in rural areas.


CONCLUSIONS
The high rate of ARTI in the eastern zone of India suggests a need for committed, sustained action in provision of quality tuberculosis control services.
Chadha
V K
VK
National Tuberculosis Institute, Bangalore, Karnataka, India. vin_chadha@rediffmail.com
Kumar
P
P
Gupta
J
J
Jagannatha
P S
PS
Lakshminarayana
Magesh
V
V
Jameel
A
A
Sanjay
S
S
Srivastava
R K
RK
Prasad
N
N
Vaidyanathan
P S
PS
D001500:BCG Vaccine / Q000009:adverse effects / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D002921:Cicatrix / Q000453:epidemiology / Q000209:etiology; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D015995:Prevalence; D018570:Risk Assessment; D012424:Rural Population / Q000706:statistics & numerical data; D014374:Tuberculin Test; D014376:Tuberculosis / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission*; D014505:Urban Population / Q000706:statistics & numerical data
D001500:BCG Vaccine