What are the risks of harmful bacteria in healthcare water systems?
Healthcare water systems are a recognised source of harmful bacteria, including Legionella, which causes Legionnaires’ disease, and Pseudomonas aeruginosa, which can colonise and infect vulnerable patients. Because Legionella grows where water is stored at between 20°C and 60°C, keeping water stored and distributed above 60°C is a key way to control the risk.
In this article, adapted from IDRONICS UK Issue 2, we look at where the risk comes from, how Legionnaires’ disease spreads and the guidance healthcare facilities managers need to follow.
Why water safety matters in healthcare settings
Patients in hospitals and healthcare settings are often at their most vulnerable, so the water systems used in their care need to be reliable, safe and effective. The same is true in care homes, where many residents are vulnerable too.
Healthcare estates have also had to perform beyond their designed capacity at times, including bringing dormant spaces back into use for vulnerable patients.
What Is HTM 04-01?
For healthcare facilities managers, HTM 04-01 – Safe Water in Healthcare Premises is a fundamental memorandum. It must be adhered to when working with the wider operations team to adapt dormant spaces so they’re safe to accommodate vulnerable patients. Altecnic Academy’s free CIBSE-approved CPD sessions on Legionella control include a dedicated session on Legionella considerations when reactivating buildings.
What HTM 04-01 Part C Says About Pseudomonas aeruginosa
HTM 04-01 Part C – Pseudomonas aeruginosa – advice for augmented care units, describes how:
“Hospital water is a recognised potential source of Pseudomonas aeruginosa, which is a microorganism that can act as an opportunistic pathogen and colonise and infect vulnerable patients. Several outbreaks of P. aeruginosa have been attributed to contaminated water systems in hospitals.”
How is Legionnaires’ Disease spread?
Legionnaires’ disease is responsible for approximately 2–9% of pneumonia cases. It’s spread by breathing in aerosolised water contaminated with Legionella bacteria.
Where can contaminated water droplets be created?
Aerosolised water contaminated with Legionella can be created in environments such as:
● Hot and cold water outlets
● Atomisers
● Wet air conditioning plants
● Whirlpool or hydrotherapy baths
Temperature ss the key to controlling Legionella
Harmful bacteria, such as Legionella, grow in water systems where water is stored at between 20°C and 60°C. So it makes sense to keep water stored and distributed at temperatures above 60°C to thermally disinfect systems, without the use of chemicals.
Hot water storage brings its own challenges
Storing water at disinfection temperatures controls bacterial growth, but it raises two further issues that the rest of this series covers:
● Scalding risk – HBN 00-10 Part C advises that outlets above 46°C present a scalding risk. In Part 2, we look at how thermostatic mixing valves (TMVs) blend hot and cold water to deliver a safe, constant temperature at the outlet.
● The dead leg – The pipework between a TMV and the outlet, known as the dead leg, is where bacteria can still form. Part 5 explains why thermal disinfection needs to reach right up to the outlet. This content was originally published in IDRONICS UK Issue 2 in September 2021.
Adapted from an editorial by Stephanie Allchurch, Product Development Manager at Altecnic.
FAQs
What temperature does Legionella grow at?
Legionella grows in water systems where water is stored at between 20°C and 60°C. Storing and distributing water above 60°C thermally disinfects the system without the need for chemicals.
What is HTM 04-01?
HTM 04-01 – Safe Water in Healthcare Premises is a Health Technical Memorandum and a fundamental reference for healthcare facilities managers. It must be adhered to when working with wider operations teams to adapt dormant spaces so they’re safe for vulnerable patients. Part C gives specific advice on Pseudomonas aeruginosa in augmented care units.
How is Legionnaires’ disease spread?
Legionnaires’ disease is spread by breathing in aerosolised water contaminated with Legionella bacteria. It accounts for approximately 2–9% of pneumonia cases.
Where can Legionella grow in a building’s water system?
Legionella grows in water systems where water is stored at between 20°C and 60°C. The contaminated water droplets that spread Legionnaires’ disease can be created at hot and cold water outlets, atomisers, wet air conditioning plants, and whirlpool or hydrotherapy baths.
Why is Pseudomonas aeruginosa a concern in hospitals?
HTM 04-01 Part C describes hospital water as a recognised potential source of Pseudomonas aeruginosa, a microorganism that can act as an opportunistic pathogen and colonise and infect vulnerable patients. Several outbreaks have been attributed to contaminated water systems in hospitals.