Evaluation of an Amplified Mycobacterium Tuberculosis Direct Test in clinical specimens

SETTING: An increase in tuberculosis cases has been observed since the last decade, and rapid and specific tests are needed to directly detect Mycobacterium tuberculosis in respiratory specimens. The Amplified Mycobacterium Tuberculosis Direct Test (AMTDT) is a direct specimen assay for the identification of M. tuberculosis. OBJECTIVE: To evaluate the sensitivity and specificity of the AMTDT. METHODS: We performed the test in 426 patients: 58 patients who had culture-proven and/or clinically diagnosed tuberculosis, and 368 patients who were negative for M. tuberculosis by culture and clinical criteria (the control group). The results were compared to culture and clinical diagnosis of tuberculosis. RESULTS: AMTDT was found to be positive in 35 of the 58 patients who had culture-proven and/or clinically diagnosed tuberculosis and 71 of the 368 controls. Seventeen of the tuberculosis group were smear-negative, and AMTDT was positive in 11 of these patients. The sensitivity and specificity of the test were respectively 60% and 80%. CONCLUSION: AMTDT can be used as a complementary technique in tuberculosis patients in the presence of high clinical suspicion.