Diagnosis and management of tuberculosis

Traditional laboratory methods used in the diagnosis of Mycobacterium tuberculosis are hindered by the organism being fastidiously slow growing. This has previously meant that species identification and drug sensitivity testing could take several weeks. New molecular biological techniques, which can be applied to both clinical samples and cultured isolates, have accelerated this diagnostic process to a number of days. The molecular biological methods used to identify M. tuberculosis and allow rapid drug susceptibility testing are reviewed. Novel molecular strain typing ("fingerprinting") techniques to discriminate between different isolates are discussed. The impact of these new methods on management is also reviewed.