SETTING: Tuberculosis sanatoria and villages in Bangalore district. OBJECTIVES: To study the appropriateness of continuing to use 1TU dilutions prepared by the BCG Laboratory, Guindy, in Chennai, India, from a freeze-dried form of PPD RT23 with Tween 80 received from Statens Serum Institut (SSI), Copenhagen, for tuberculin surveys in India. DESIGN: The responses to dual tuberculin tests were compared among: 1) 63 smear-positive cases using 2TU PPD prepared by the Guindy laboratory (Dilution-G), and 2TU PPD prepared by the SSI (Dilution-S); 2) 124 smear-positive cases using 1TU and 2TU Dilution-G; and 3) 1,338 apparently healthy children using 1TU and 2TU Dilution-G. Test sites were allocated randomly using the double-blind technique. Tuberculin responses obtained during studies conducted in India and in other countries were compared. RESULTS: The differences in sensitivity of tuberculin testing using the different preparations were found to be small and statistically non-significant. Among children, a higher proportion of reaction sizes in 10-14 mm and 15 + mm categories was observed to 2TU compared to 1TU of Dilution-G. This could reflect lower specificity of 2TU in the study area where non-specific sensitivity is highly prevalent. Studies in India and other countries do not suggest any loss in potency of 1TU PPD RT23 with Tween 80. CONCLUSION: 1TU dilutions of PPD RT23 with Tween 80 provided by the BCG Laboratory, Guindy, may continue to be used for tuberculin surveys in India.
RCT Entities:
SETTING:Tuberculosis sanatoria and villages in Bangalore district. OBJECTIVES: To study the appropriateness of continuing to use 1TU dilutions prepared by the BCG Laboratory, Guindy, in Chennai, India, from a freeze-dried form of PPD RT23 with Tween 80 received from Statens Serum Institut (SSI), Copenhagen, for tuberculin surveys in India. DESIGN: The responses to dual tuberculin tests were compared among: 1) 63 smear-positive cases using 2TU PPD prepared by the Guindy laboratory (Dilution-G), and 2TU PPD prepared by the SSI (Dilution-S); 2) 124 smear-positive cases using 1TU and 2TU Dilution-G; and 3) 1,338 apparently healthy children using 1TU and 2TU Dilution-G. Test sites were allocated randomly using the double-blind technique. Tuberculin responses obtained during studies conducted in India and in other countries were compared. RESULTS: The differences in sensitivity of tuberculin testing using the different preparations were found to be small and statistically non-significant. Among children, a higher proportion of reaction sizes in 10-14 mm and 15 + mm categories was observed to 2TU compared to 1TU of Dilution-G. This could reflect lower specificity of 2TU in the study area where non-specific sensitivity is highly prevalent. Studies in India and other countries do not suggest any loss in potency of 1TU PPD RT23 with Tween 80. CONCLUSION: 1TU dilutions of PPD RT23 with Tween 80 provided by the BCG Laboratory, Guindy, may continue to be used for tuberculin surveys in India.
Authors: Madhukar Pai; Rajnish Joshi; Sandeep Dogra; Deepak K Mendiratta; Pratibha Narang; Shriprakash Kalantri; Arthur L Reingold; John M Colford; Lee W Riley; Dick Menzies Journal: Am J Respir Crit Care Med Date: 2006-05-11 Impact factor: 21.405
Authors: M Pai; R Joshi; S Dogra; A A Zwerling; D Gajalakshmi; K Goswami; M V R Reddy; A Kalantri; P C Hill; D Menzies; P C Hopewell Journal: Int J Tuberc Lung Dis Date: 2009-01 Impact factor: 2.373