While ‘temperature’ is the standard ‘traditional method of control’ for monitoring waterborne bacteria such as Legionella in hospitals and healthcare water distribution systems, there are nowadays many ways to suitably disinfect those systems (physical, chemical as well as thermal) so that it mitigates the risk of system-wide colonisation and associated disease and infection – when patients are in contact with waterborne pathogens. Even though these measures can mitigate the risks, it is always a good idea to run a professional Legionella risk assessment to ensure your premises are minimising their exposure and risks.
Strategies to monitor waterborne pathogens
It is well known that the sufficient turnover of water (including the flushing of not frequently used outlets) as well as adherence to the prescribed cold and hot water temperatures determine the strategies of water treatment that can be used to monitor waterborne pathogens like Pseudomonas and Legionella in health structures. First of all, the speed or movement of water while under sufficient pressure will create a ‘shearing’ force inside the system that prevents the formation of planktonic bacterial cells on the inner surface of pipe work. Thus, these planktonic cells (widespread in the environment) as well as system-wide particulate are moved in the water system and harmlessly flushed to drain. Then, waterborne pathogens like Legionella usually grow or multiply between the temperatures of 20-45°C. Therefore, ensured that the hot water is ‘hot’ (stored at 60°C and retuned at ≥55°C – in healthcare…) and the cold water is ‘cold’ (≤20°C), the sufficient turnover of water and a good temperature control remain effective methods for monitoring the bacterial weight and associated waterborne pathogens in hospitals and health structures.
Reduce the risk of colonisation
Getting rid of the stagnation of water is imperative for reducing the risk of biofilm formation – both inside the asset (shower or tap) and the system. Therefore, as well as guaranteeing an outlet is in frequent use, it is also important to ensure that these outlets are free from scale and suitably cleaned. The sufficient cleaning of assets will help to reduce the risk of colonisation from biofilm bacteria like Pseudomonas, that is an opportunistic microorganism which often colonises inadequately maintained or infrequently used outlets. Pseudomonas is considered a ‘primary infecting organism’ because of its biofilm-forming nature and often offers a suitable environment for other – sometimes pathogenic – organisms to grow inside, like Legionella – considered a ‘secondary infecting organism’. Legionella bacteria will infrequently survive outside of a protozoan host or biofilm, thus in making sure that outlets are free from scale, this will help to reduce the risk of people getting a waterborne infection. Therefore, it is imperative to monitor the environment in which aquatic bacteria can grow and proliferate as well as to control the risk…
Scale formation vary based on the structure’s geographic location, thus, deep consideration must be given to the ‘natural chemistry’ of the water system that is managed and cleaning frequency, ‘hard water’ areas (those with an abundance of calcium carbonate) undoubtedly requiring greater vigilance than ‘soft water’ areas because they are more likely to produce scale. For this reason ‘periodic’ cleaning is advised.
Reduce the risk of cross-contamination
The importance of adequately cleaning outlets while making sure that assets are not misused (WHB are used for hand washing…), is imperative to reduce the risk of sensitive or augmented care patients from being affected by Pseudomonas aeruginosa thus making water hygiene a matter of the utmost importance. This is to not only ensure that assets are suitably cleaned, but to also reduce the risk of cross-contamination of assets (WHB & taps) with waterborne bacteria like Pseudomonas. Thus, it is important to understand that while it is known that tap and shower outlets can be a reservoir for contamination by bacteria like Pseudomonas, we must also consider that Pseudomonas bacteria are widespread. Therefore, if an outlet becomes colonised with these bacteria, it doesn’t mean that the associated water system always represent the cause of the problem especially when non-conformances have been observed from either a misuse or cleaning perspective.