WATER HYGIENE AND SAFETY ‘‘
Design and commissioning are important aspects for microbial control, yet during the build stage many parts of the water systems are left stagnant following pressure testing, which results in water contamination prior to occupation
A ‘trained and competent’ WSG The establishment of a trained and competent Water Safety Group is crucial to the safe management of the healthcare water system, and the WSG needs to ensure that the Water Safety Plan identifies inherent risks within the building. This will involve reviewing i) the physical build – by inspecting the cold water tanks to ensure that they are clean and not oversized, that calorifiers are reaching at least 60 °C, pipes are insulated, water is moving through all the loops, and that water is being effectively drawn off at all the outlets to avoid stagnation and microbial growth, and ii), assessing the temperature of both the hot and cold water system is crucial to controlling the growth of microorganisms, i.e. keeping the cold water below 20 °C and the hot water distributed above 55 °C (Figure 3). Measuring temperatures is normally carried out manually by someone with a thermometer, with ward staff operating outlets and recording this using paper log sheets. More recently, automated temperature recording of the cold water storage, and calorifier flow and return temperatures, has been introduced through building management systems. However, to understand whether temperature and flow regimens across the hospital and, particularly in the augmented care units, are controlling L. pneumophila, remote monitoring should be considered. By deploying temperature sensors on the hot and cold water supplies including water outlets, frequent temperature measurements can be recorded automatically, and analysed using algorithms, in real time, to identify microbial risks. Good preventative practice could then include automated flushing of underused outlets. Even when these control measures
are followed, verified, and documented, it is critical for Water Safety Groups to measure their effectiveness by sampling for Legionella. WSGs should focus their efforts and testing on L. pneumophila, as efforts to address non-pneumophila species use valuable resources, and draw focus away from the detection and remediation of L. pneumophila to minimise the risk to vulnerable patients.
References 1 Llewellyn AC, Lucas CE, Roberts SE, Brown EW, Nayak BS, Raphael BH. Distribution of Legionella and bacterial
community composition among regionally diverse US cooling towers. PLoS One, 2017; 12(12).
2 Muder RR, Yu LV. (2002) Infection Due to Legionella Species Other Than L. pneumophila, Clin Infect Dis 2002; 35(8) 990-8.
3 ISO. ISO 11731:2017, Water quality – Enumeration of Legionella. 2017; Available from
https://www.iso.org/obp/ ui/#iso:std:11731:ed-2v1:en
4 PHE. Legionnaires’ disease in residents in England and Wales – 2016. 2018; Available from
https://assets.publishing.
service.gov.uk/government/uploads/ system/uploads/attachment_data/ file/696376/2016_Annual_Report_final. pdf
5 Campese C, Bitar D, Jarraud S, Maine C, Forey F, Etienne J Progress in the surveillance and control of Legionella infection in France, 1998-2008. Int J Infect Dis 2011; 15(1):e30–7.
6 ECDC. Legionnaires’ disease – Annual Epidemiological Report for 2019. European Centre for Disease Prevention and Control [Internet]. 2021; Available from:
https://www.ecdc.europa.eu/en/ publications-data/legionnaires-disease- annual-epidemiological-report-2019
7 Amemura-Maekawa J, Kura F, Chida K, Ohya H, Kanatani J, Isobe J. Legionella pneumophila and other Legionella species isolated from Legionellosis patients in Japan between 2008 and 2016. Appl Environ Microbiol 2018; 84(18).
8 CDC. National Outbreak Reporting System (NORS) Dashboard. 2021 [cited 2022 Apr 6]; Available from: https://
wwwn.cdc.gov/norsdashboard/
9 Beauté J, Plachouras D, Sandin S, Giesecke J, Sparén P. Healthcare- Associated Legionnaires’ Disease, Europe, 2008–2017. Emerg Infect Dis 2020; 26(10): 2309–18.
10 Wee BA, Alves J, Lindsay DSJ, Klatt A-B, Sargison FA, Cameron RL Population analysis of Legionella pneumophila reveals a basis for resistance to complement-mediated killing. Nat Commun 2021;12(1):7165.
11 Berdal BP, Farshy CE, Feeley JC. Detection of Legionella pneumophila antigen in urine by enzyme-linked immunospecific assay. J Clin Microbiol 1979;9 (5):575–8.
12 Uldum SA, Helbig JH. Legionella serogroup and subgroup distribution among patients with Legionnaires’ Disease in Denmark. In: Legionella. John
Dr Jimmy Walker
Jimmy Walker PhD, BSc, is a microbiologist with over 30 years’ experience in water microbiology and decontamination. He previously worked for Public Health England, managing a range of projects on biofilms and pathogens such as Legionella spp., Pseudomonas aeruginosa, and Mycobacteria spp. Through PHE, he worked with the Department of Health and the HSE in writing and developing national and international guidance on the microbiology of water and decontamination in healthcare. On leaving PHE he established his independent consultancy, Walker on Water. The current Chair of the Central Sterilising Club, and the Decontamination Professional Experts Committee Forum, he regularly publishes on water microbiology, and is currently writing a new book, entitled Safe Water in Healthcare, as ‘a practical guide for the non-expert’, to be published later this year.
May 2022 Health Estate Journal 35 Wiley & Sons, Ltd; 2001. p. 200–3.
13 SSI. Legionnaires’ disease 2019. EPI- NEWS No 20 2020 [Internet]. 2020 [cited 2022 Apr 6]; Available from: https://
en.ssi.dk/news/epi-news/2020/no-20--- 2020
14 SSI. Legionnaires’ disease in Denmark 2020. EPI-NEWS Nos 18 [Internet]. 2021 [cited 2022 Apr 6]; Available from:
https://en.ssi.dk/news/epi-news/2021/ no-18---2021
15 SSI. Legionella 2020 Annual Report. [internet] 2021 [cited April 6, 2022]. Available from
https://en.ssi.dk/ surveillance-and-preparedness/ surveillance-in-denmark/annual-reports- on-disease-incidence/legionella-2020- annual-report
16 ASHRAE. Guidance on reducing the risk of Legionella 2020 [cited 2022 Apr 6]; Available from:
https://www.ashrae. org/technical-resources/standards-and- guidelines/guidance-on-reducing-the- risk-of-legionella
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76
