Sensitivity of amplicor mtb on direct detection of Mycobacterium tuberculosis in smear-negative specimens from outpatients in Rio de Janeiro

We evaluated the performance of the AMPLICOR MTB assay for detection of M. tuberculosis in clinical specimens obtained from 98 smear-negative tuberculous patients (43 with positive and 55 with negative culture results). The sensitivity of the AMPLICOR MTB was 44.9(per cent) (44/98) and that of culture was 43.8(per cent) (43/98). No significant difference was observed between the results obtained by AMPLICOR MTB and by culture. We conclude that amplification assays could be used for testing smear-negative specimens because a rapid diagnosis will benefit those patients.