A pseudoepidemic due to atypical mycobacteria in a hospital water supply
T. M. Stine, A. A. Harris, S. Levin, N. Rivera and R. L. Kaplan
We describe a pseudoepidemic due to atypical mycobacteria contaminating the
water used by a pathology laboratory and bronchoscopy suite on two floors
of the same hospital building. Inspection of laboratory procedures revealed
that contamination occurred during specimen processing in pathology and
while obtaining the bronchoscopic specimens. Mycobacterium gordonae,
Mycobacterium avium complex, and Mycobacterium scrofulaceum were
identified. During an eight-month period, a total of 22 (31%) of 70
patients with positive acid-fast smears had either an illness inconsistent
with tuberculosis or a known alternate diagnosis. Control was easily
obtained by insertion of a 0.2-micron polymer filter into the outflow
tubing of our pathology tap water-deionizing unit and the tap water source
in the bronchoscopy suite. The pseudoepidemic led to additional
diagnostic-therapeutic intervention, but no patient experienced delay in
appropriate diagnosis. Pseudoepidemics due to atypical mycobacteria will
likely be of increased importance in institutions providing care to
patients with acquired immunodeficiency syndrome.
