A cluster of cases of nosocomial legionnaires disease linked to a contaminated hospital decorative water fountain.
BACKGROUND
Nosocomial outbreaks of Legionnaires disease have been linked to contaminated water in hospitals. Immunocompromised patients are particularly vulnerable and, when infected, have a high mortality rate. We report the investigation of a cluster of cases of nosocomial pneumonia attributable to Legionella pneumophila serogroup 1 that occurred among patients on our stem cell transplantation unit.


METHODS
We conducted a record review to identify common points of potential exposure, followed by environmental and water sampling for Legionella species from those sources. We used an air sampler to in an attempt to detect aerosolized Legionella and pulsed-field gel electrophoresis to compare clinical and environmental isolates.


RESULTS
The most likely sources identified were the water supply in the patients' rooms and a decorative fountain in the radiation oncology suite. Samples from the patients' rooms did not grow Legionella species. Cultures of the fountain, which had been restarted 4 months earlier after being shut off for 5 months, yielded L. pneumophila serogroup 1. The isolates from both patients and the fountain were identical by pulsed-field gel electrophoresis. Both patients developed pneumonia within 10 days of completing radiation therapy, and each reported having observed the fountain at close range. Both patients' infections were identified early and treated promptly, and both recovered.


CONCLUSIONS
This cluster was caused by contamination of a decorative fountain despite its being equipped with a filter and ozone generator. Fountains are a potential source of nosocomial Legionnaires disease despite standard maintenance and sanitizing measures. In our opinion, fountains present unacceptable risk in hospitals serving immunocompromised patients.
Palmore
Tara N
TN
Warren Grant Magnusen Clinical Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-1888, USA. tpalmore@mail.nih.gov
Stock
Frida
F
White
Margaret
M
Bordner
MaryAnn
M
Michelin
Angela
A
Bennett
John E
JE
Murray
Patrick R
PR
Henderson
David K
DK
D000328:Adult; D016000:Cluster Analysis; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission*; D004866:Equipment Contamination; D006757:Hospital Units; D006801:Humans; D016867:Immunocompromised Host; D016952:Legionella pneumophila / Q000145:classification / Q000302:isolation & purification; D007877:Legionnaires' Disease / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission*; D008297:Male; D014871:Water Microbiology