One-third of the world’s population is infected with latent TB (LTBI). Along the Mexico-Arizona border, LTBI is diagnosed using the tuberculin skin test (TST). Cross reactive responses due to BCG vaccination or environmental mycobacteria can lead to false positive results, leading to unnecessary follow-up. New methods of detection more specific than TST have been developed, such as Quantiferon TB gold In-Tube (QFT-GIT). Our objective is to demonstrate utility and feasibility of the QFT-GIT test to detect LTBI among border populations.