Dépôt numérique
RECHERCHER

Temperature diagnostic to identify high risk areas and optimize Legionella pneumophila surveillance in hot water distribution systems

Bédard, Émilie; Fey, Stéphanie; Charron, Dominique; Lalancette, Cindy; Cantin, Philippe; Dolcé, Patrick; Laferrière, Céline; Déziel, Éric; Prévost, Michèle (2015). Temperature diagnostic to identify high risk areas and optimize Legionella pneumophila surveillance in hot water distribution systems Water Research , vol. 71 . p. 244-56. DOI: 10.1016/j.watres.2015.01.006.

[img]
Prévisualisation
PDF - Version acceptée
Télécharger (583kB) | Prévisualisation
[img]
Prévisualisation
PDF - Matériel supplémentaire
Télécharger (1MB) | Prévisualisation
[img]
Prévisualisation
PDF - Matériel supplémentaire
Télécharger (575kB) | Prévisualisation
[img]
Prévisualisation
PDF - Matériel supplémentaire
Télécharger (553kB) | Prévisualisation
[img]
Prévisualisation
PDF - Matériel supplémentaire
Télécharger (376kB) | Prévisualisation

Résumé

Legionella pneumophila is frequently detected in hot water distribution systems and thermal control is a common measure implemented by health care facilities. A risk assessment based on water temperature profiling and temperature distribution within the network is proposed, to guide effective monitoring strategies and allow the identification of high risk areas. Temperature and heat loss at control points (water heater, recirculation, representative points-of-use) were monitored in various sections of five health care facilities hot water distribution systems and results used to develop a temperature-based risk assessment tool. Detailed investigations show that defective return valves in faucets can cause widespread temperature losses because of hot and cold water mixing. Systems in which water temperature coming out of the water heaters was kept consistently above 60 degrees C and maintained above 55 degrees C across the network were negative for Legionella by culture or qPCR. For systems not meeting these temperature criteria, risk areas for L. pneumophila were identified using temperature profiling and system's characterization; higher risk was confirmed by more frequent microbiological detection by culture and qPCR. Results confirmed that maintaining sufficiently high temperatures within hot water distribution systems suppressed L. pneumophila culturability. However, the risk remains as shown by the persistence of L. pneumophila by qPCR.

Type de document:
Mots-clés libres: Culturability; Legionella pneumophila; Premise plumbing; Temperature profile; Thermal control; Viable but not culturable (VBNC)
Centre: Centre INRS-Institut Armand Frappier
Date de dépôt: 05 janv. 2016 22:09
Dernière modification: 08 mai 2017 20:44
URI: http://espace.inrs.ca/id/eprint/3147

Actions (Identification requise)

Modifier la notice Modifier la notice