<  Back to the Polytechnique Montréal portal

Energy conservation and the promotion of Legionella pneumophila growth: The probable role of heat exchangers in a nosocomial outbreak

Émilie Bédard, Simon Levesque, Philippe Martin, Linda Pinsonneault, Kirand Paranjape, Cindy Lalancette, Charles-Éric Dolce, Manuela Villion, Louis Valiquette, Sébastien P. Faucher and Michèle Prévost

Article (2016)

Published Version
Terms of Use: Creative Commons Attribution .
Download (398kB)
Cite this document: Bédard, É., Levesque, S., Martin, P., Pinsonneault, L., Paranjape, K., Lalancette, C., ... Prévost, M. (2016). Energy conservation and the promotion of Legionella pneumophila growth: The probable role of heat exchangers in a nosocomial outbreak. Infection Control & Hospital Epidemiology, 37(12), p. 1475-1480. doi:10.1017/ice.2016.205
Show abstract Hide abstract


OBJECTIVE To determine the source of a Legionella pneumophila serogroup 5 nosocomial outbreak and the role of the heat exchanger installed on the hot water system within the previous year. SETTING A 400-bed tertiary care university hospital in Sherbrooke, Canada. METHODS Hot water samples were collected and cultured for L. pneumophila from 25 taps (baths and sinks) within wing A and 9 taps in wing B. Biofilm (5) and 2 L water samples (3) were collected within the heat exchangers for L. pneumophila culture and detection of protists. Sequence-based typing was performed on strain DNA extracts and pulsed-field gel electrophoresis patterns were analyzed. RESULTS Following 2 cases of hospital-acquired legionellosis, the hot water system investigation revealed a large proportion of L. pneumophila serogroup 5 positive taps (22/25 in wing A and 5/9 in wing B). High positivity was also detected in the heat exchanger of wing A in water samples (3/3) and swabs from the heat exchanger (4/5). The outbreak genotyping investigation identified the hot water system as the source of infections. Genotyping results revealed that all isolated environmental strains harbored the same related pulsed-field gel electrophoresis pattern and sequence-based type. CONCLUSIONS Two cases of hospital-acquired legionellosis occurred in the year following the installation of a heat exchanger to preheat hospital hot water. No cases were reported previously, although the same L. pneumophila strain was isolated from the hot water system in 1995. The heat exchanger promoted L. pneumophila growth and may have contributed to confirmed clinical cases. Infect. Control Hosp. Epidemiol. 2016;1475-1480.

Uncontrolled Keywords

Canada; Conservation of Energy Resources/methods; Cross Infection/*microbiology/*transmission; Disease Outbreaks; Electrophoresis, Gel, Pulsed-Field; Environment, Controlled; Female; Genotype; Hospitals, University; Hot Temperature/*adverse effects; Humans; Legionella pneumophila/genetics/*isolation & purification; Legionnaires' Disease/*transmission; Male; *Water Microbiology; Water Supply

Open Access document in PolyPublie
Subjects: 1000 Génie civil > 1000 Génie civil
1000 Génie civil > 1007 Ressources et approvisionnement en eau
5200 Microbiologie > 5201 Bactériologie
Department: Département des génies civil, géologique et des mines
Research Center: Non applicable
Funders: NSERC Industrial Chair on Drinking Water, Fonds de Recherche Nature et Technologie Québec (FQRNT)
Date Deposited: 07 Apr 2021 11:01
Last Modified: 08 Apr 2021 10:43
PolyPublie URL: https://publications.polymtl.ca/4774/
Document issued by the official publisher
Journal Title: Infection Control & Hospital Epidemiology (vol. 37, no. 12)
Publisher: Cambridge University Press
Official URL: https://doi.org/10.1017/ice.2016.205


Total downloads

Downloads per month in the last year

Origin of downloads


Repository Staff Only