Agreement between skin testing and QuantiFERON-TB Gold In-Tube assay (QFT-TB) in detecting latent tuberculosis infection among household contacts in India.

AIMS: The present study was designed to find the agreement between Tuberculin Skin Test and interferon gamma assay test in detecting latent tuberculosis infection in household contacts of sputum culture positive tuberculosis cases. SETTING: Department of Community Medicine, Christian Medical College, Vellore. METHODS: One hundred and fifty household contacts of sputum culture positive tuberculosis cases were tested with both the methods simultaneously and actual as well as kappa agreement was determined. RESULTS: The overall actual agreement between both the tests was found to be 82% with a kappa agreement of 0.57. CONCLUSION: The agreement was very high (both percentage agreement and Kappa) in pediatric contacts but it was poor in adult contacts.