WATER SYSTEM HYGIENE AND SAFETY
How to successfully manage Legionella risk
Les Szabo, NSW (New South Wales) State manager at Australian water treatment specialist, HydroChem, discusses work to implement an effective Legionella risk management and prevention strategy for the hot water system at a Sydney hospital. Among the key steps taken to address the existing protocols’ shortcomings were establishing a proper sampling protocol, implementing a monthly maintenance programme for chlorine dosing, taking samples from locations on each floor – with a focus on showers, and installing a chorine dosing unit equipped with remote telemetry.
Legionnaires’ disease, and the control of Legionella bacteria in potable water systems, are challenges particular to healthcare facilities for two main reasons: 1 Hospitals require the delivery of warm water for the use of patients at handbasins and showers.
2 Patients in hospitals have a higher risk of developing illness than the general population.
Hot water delivered from either instantaneous or stored water boilers is usually maintained and delivered to outlets at approximately 60 °C. At this temperature there is a risk of scalding. As a result, it is a general requirement in hospitals that the water delivered at outlets is mixed with cold water to deliver water at a temperature no higher than 45 °C.
A difficult balance Unfortunately, maintaining water at a safe level to prevent scalding is the ideal temperature to promote the proliferation of Legionella bacteria. The genus Legionella, which comprises over 50 different species, has evolved to survive in the natural environment in soil, rivers, and lakes. Legionella cannot fulfil its lifecycle without invading a host, taking nutrients from the host, and then multiplying. Typically, a warm, swamp-like environment is the ideal location where Legionella can multiply in the presence of other microorganisms like slimes and amoeba. While in nature, the temperature
variations between seasons and overnight help to mitigate the rate of bacterial multiplication, in our highly controlled environments we often create a constant temperature range that is perfect for certain microorganisms. Legionella will generally remain dormant below 20 °C, and will die above 60 °C. The ideal temperature for proliferation is the same as the target temperature for warm water systems. Given that Legionella have evolved over millions of years, and survive in the natural environment, it is highly likely that most of us have been exposed to the bacteria
30 Health Estate Journal February 2024
Figure 1: A simple flowchart showing the simplified process used by the case study small hospital in Sydney to address Legionella risk.
without becoming ill. Legionnaires’ disease is predominantly identified in patients with weakened immune systems or other underlying health conditions. The proximity of such patients in the hospital environment increases the likelihood of an outbreak should the bacteria contaminate the water distribution system.
Compliance The control of warm water to prevent scalding is mandatory in all states and territories of Australia. The regulators recognise the increased risk of Legionella bacteria and, as a result, water hygiene within the hospital environment is also
either regulated or stipulated through guidelines issued to the healthcare industry, including aged care facilities. For operational managers within healthcare facilities, one of the major impetuses for taking steps is the requirement to ensure compliance with regulations, to the letter of the expectation. Prima facie, this will satisfy the duty of care, and mitigate any claims of negligence. In my experience, the first step taken by operational managers is often seeking to meet the requirements stipulated. At times, this step is taken without the understanding of how each individual component fits together to achieve an outcome.
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
