Mycobacterial infection

Last updated: Thursday, 23, December, 2010
Key InformationAppropriate Tests

Mycobacteria testing on appropriate specimens to detect acid fast bacilli.

Histological examination of a biopsy will often suggest the diagnosis. It is important that appropriate handling of the biopsy is discussed with the pathologist before the specimen is collected.

HIV testing if appropriate, with consent and after counselling.

See HIV infection, Infection (increased susceptibility)



Atypical mycobacterial infection

Lung infection, especially

  • Mycobacterium avium complex, M. kansasii, M. chelonae

Sputum microscopy and culture; bronchial brush, wash; bronchoalveolar lavage for mycobacteria testing.

Skin infection, especially

  • M. chelonae, M. abscessus, M. fortuitum, M. marinum, M. ulcerans

Skin biopsy is much more likely to detect infection than a wound swab.

If an ulcer is present, deep biopsy of the edge is preferred, eg, Bairnsdale (Buruli) ulcer caused by M. ulcerans.

Cervical lymphadenopathy, especially

  • M. avium, M. intracellulare, M. scrofulaceum

Lymph node biopsy, including  FNAB, with mycobacteria testing.

Arthritis/tenosynovitis, especially

  • M. marinum, M. fortuitum, M. chelonae

Synovial fluid examination is of less value than synovial tissue biopsy for mycobacteria testing.

Disseminated/multifocal, especially

  • M. avium, M. intracellulare

More likely to occur in patients on steroid therapy or with other immunodeficient states eg, AIDS.