Evaluation of the usefulness of phage amplification technology in the diagnosis of patients with paucibacillary tuberculosis

The present study was undertaken to assess the performance of the Fast Plaque TB(TM) (FPTB) test in the diagnostically difficult group of paucibacillary tuberculosis (TB) and to compare its results with the conventional bacteriological methods. The study was conducted on a total of 139 patients, who were negative for TB in sputum-smear examination. Bronchoalveolar lavage (BAL) or pleural biopsy specimens collected from these patients were subjected to smear examination, LJ culture and FPTB test. The smear, culture and the FPTB positivity rates were compared between patients with pulmonary and pleuro-pulmonary involvement. The FPTB test was found to register an overall sensitivity of 58.8% and specificity of 97.9%. The positive and negative predictive values of the test were 98.1 and 56.5, respectively. Among patients with paucibacillary TB, on head-to-head comparison, we found that the sensitivity and specificity values of the FPTB test were marginally better than smear-microscopy and inferior to culture on LJ media.