Last update:
16-Oct-2008

Although nontuberculous mycobacteria (NTM) were observed soon after Koch's discovery of Mycobacterium tuberculosis, the clinical significance of NTM was not appreciated until the 1950s when they were classified as "atypical mycobacteria" on the basis of their in vitro characteristics. Since this time many large series of both HIV-positive and -negative patients, suffering from pulmonary and extrapulmonary diseases attributable to what are now named "nontuberculous mycobacteria" have been described. Most NTM organisms have been isolated from water, soil and dust, so their growth in respiratory secretion culture may raise the question of specimen contamination and can not always document disease. Many epidemiologic studies have demonstrated that the prevalence of NTM disease is variable and differs between geographic regions. NTM cause variable clinical and radiographic features which are not usually distinct from those caused by M. tuberculosis. The increase in HIV prevalence in developed countries and improvements in methods of detection and culture have contributed to the apparent increase in disease burden. In response to this increase in the burden of the disease the American Thoracic Society (ATS) in 1997 and the British Thoracic Society (BTS) in 1999 issued guidelines on the diagnosis and management of NTM infections. Both sets of guidelines highlight the difficulties of identifying patients with clinical disease, and indicate that the success rates with the suggested therapeutic regimens are often poor, with failure to eradicate the organisms and recurrence of disease after cessation of therapy.

Key words: Diagnosis, Epidemiology, Nontuberculous mycobacteria, Treatment.