Sources of the atypical mycobacteria:
(1) tap water or ice given to a patient prior to sputum collection
(2) tap water used to rinse bronchoscopy or endoscopy equipment
(3) tap water used to prepare smears or slides for acid fast staining
Patients at risk for being misdiagnosed and receiving unnecessary therapy:
(1) immunosuppressed
(2) have granulomatous inflammation
(3) have fever of unknown origin, weight loss or other findings compatible with tuberculosis
How the problem may be detected:
(1) There is a cluster of cases over a short period of time.
(2) The presence or number of the acid fast bacilli is not compatible with the clinical picture.
(3) Acid fast bacilli are seen outside of areas showing granulomatous inflammation, especially when outside of section or smear.
(4) Someone correlates the appearance of the problem with recent work or change in water supply.
(5) The species of myobacterium isolated on culture is an unusual cause of human disease.
NOTE: People who are unaware of the problem of contaminated water supplies can come up with some very creative ways to explain the findings.
