Annual risk of tuberculous infection in three districts of maharashtra

摘要

A nation wide tuberculin survey to estimate the annual risk of tuberculous infection (AR1) in different parts of India is cunently under progress. Three districts viz. Nagpur, Thane and Ratnagiri were selected from the state of Maharashtra, as a part of the survey. A total of 29,966 children in the age group 1 to 9 years from the rural and urban areas of these three districts were subjected to tuberculin testing with 'ITU PPDRT23 with Tween 80' and maximum transverse diameter of induration was measured about 72 hours later. The cut-off point for identification of 'infection with tubercle bacilli' was identified at 15 mm, based on the frequency distribution of reaction sizes.The ARI rates estimated among children without BCG scar in the rural areas of Nagpur, Thane and Ratnagiri districts were 1.2%, 1.6% and 1.8% respectively. In urban areas of Nagpur and Thane districts, the estimated ARI rates of 1.6% and 3.3% respectively were significantly higher than in rural areas.The findings indicate a high rate of transmission of tuberculous infection in the community and suggest further intensification of tuberculosis control measures, especially in urban areas.