Infections due to non-tuberculous mycobacteria

**Definition:** Any condition caused by an infection with Mycobacteria excluding infections due to Mycobacterium tuberculosis complex and Mycobacterium leprae. These conditions commonly present with lung disease; however, symptoms are dependent on the site of infection. Transmission is by direct contact with non-tuberculous Mycobacteria in the environment. Confirmation is by identification of non-tuberculous Mycobacteria from the affected site(s).

**Long definition:** Acid-fast mycobacteria other than M. Tuberculosis and M. leprae are ubiquitous and can cause a range of diseases in humans. They are known collectively as non-tuberculous or atypical mycobacteria. Disseminated infection is usually a consequence of profound immunosuppression such as that due to AIDS. The commonest presentation, however, is with localized or regional cutaneous infection. A wide variety of other presentations may be seen, amongst which lymphadenitis and pulmonary disease are prominent.

**Exclusions:** - Leprosy - Tuberculosis