MOLECULAR DIAGNOSIS OF TUBERCULOSIS - CURRENT CLINICAL VALIDITY AND FUTURE PERSPECTIVES

The rapid development and availability of a variety of new molecular g enetic technologies present the clinician with an array of options for the accurate diagnosis of infectious diseases. This is particularly t he case for tuberculosis, since molecular methods have been rapidly in troduced into all working areas of the mycobacteriology laboratory, Nu cleic acid amplification methods to detect Mycobacterium tuberculosis in clinical specimens are increasingly used as a tool to diagnose tube rculosis. The bulk of recently available data from clinical evaluation s performed under routine laboratory conditions indicate that these mo lecular methods are rapid and sensitive, but yet inferior, to culture with regard to sensitivity and specificity, Therefore, until gene ampl ification tests have proved to be reliable and quality control procedu res exist, their clinical validity remains controversial, Consequently , definition of selected clinical applications of gene amplification t o routine diagnosis of tuberculosis is important and need to be discus sed. This review will focus on the clinical role of molecular methods in the direct detection and diagnosis of M. tuberculosis in clinical s amples. In addition, molecular genetic approaches designed to determin e drug susceptibility and to discriminate strains below the species le vel will be outlined and discussed in terms of their current and futur e clinical applicability.