Annual risk of tuberculous infection in rural areasof Kota district.

ABSTRACT

Background: A nation wide tuberculin study was undertaken to estimate the Annual Risk of Tuberculous Infection (ARTI) in different parts of India. The study in the rural areas of Kota, one of the districts selected for the survey, is described in this article. Material & Methods: A total of 6264 children 1-9 years of age, residing in 64 clusters were registered into the study. The children were subjected to the standard tuberculin test using 1 TU PPD RT23 with Tween 80 procured from BCG Laboratory, Guindy and the maximum transverse diameter of the induration was measured at about 72 hours. Results: A total of 3157 children without BCG scar and 1520 with BCG scar was successfully test read. The prevalence of infection among children without BCG scar using the mirror image technique was estimated as 13.6% and the ARTI was computed at 2.6%. Using similar technique, the prevalence of infection among the entire study group-irrespective of BCG scar was estimated as 14.9% and the ARTI was computed at 2.8%. Conclusion: The findings indicate a high rate of transmission of tuberculous infection in rural areas of Kota and emphasise the need for further strengthening of tuberculosis control measures.