--- title: Chain of Infection, a reservoir of organisms description: Background to Legionella and Pseudomonas aeruginosa, including those who are most susceptible, favourable conditions, and control strategies.  image: https://www.waterhygienecentre.com/hubfs/IIRSM%20-%20COI.jpg --- [![Water-Hygiene-Centre-Logo1-2](https://www.waterhygienecentre.com/hs-fs/hubfs/Water-Hygiene-Centre-Logo1-2.png?width=225&height=80&name=Water-Hygiene-Centre-Logo1-2.png "Water-Hygiene-Centre-Logo1-2")](https://www.waterhygienecentre.com/) [![white-logo](https://www.waterhygienecentre.com/hs-fs/hubfs/WaterHygieneCentre-2019/Images/white-logo.png?width=198&height=69&name=white-logo.png "white-logo")](https://www.waterhygienecentre.com/) - [** ](https://www.facebook.com/sharer/sharer.php?u=https://www.waterhygienecentre.com/academy/chain-of-infection&title=Chain%20of%20Infection, a%20reservoir%20of%20organisms&picture=https://2896031.fs1.hubspotusercontent-na1.net/hubfs/2896031/IIRSM%20-%20COI.jpg&description=Background%20to%20Legionella%20and%20Pseudomonas%20aeruginosa, including%20those%20who%20are%20most%20susceptible,%20favourable%20conditions,%20and%20control%20strategies. ) - [**](https://twitter.com/share?source=https://www.waterhygienecentre.com/academy/chain-of-infection&text=Chain%20of%20Infection, a%20reservoir%20of%20organisms%20-%20https://www.waterhygienecentre.com/academy/chain-of-infection) - [**](http://www.linkedin.com/shareArticle?mini=true&url=https://www.waterhygienecentre.com/academy/chain-of-infection&title=Chain%20of%20Infection, a%20reservoir%20of%20organisms&summary=Background%20to%20Legionella%20and%20Pseudomonas%20aeruginosa, including%20those%20who%20are%20most%20susceptible,%20favourable%20conditions,%20and%20control%20strategies. ) # **Chain of Infection, a reservoir of organisms** by [Water Hygiene Centre](https://www.waterhygienecentre.com/academy/author/water-hygiene-centre), on 14-05-2026 Find me on: [LinkedIn](https://www.linkedin.com/company/water-hygiene-centre/?viewAsMember=true) [![IIRSM - COI](https://www.waterhygienecentre.com/hs-fs/hubfs/IIRSM%20-%20COI.jpg?width=651&height=366&name=IIRSM%20-%20COI.jpg)](https://www.waterhygienecentre.com/chain-of-infection-water) Water out of the tap, what’s the issue...?  Water is the giver of life.  Water is also the home of ‘waterborne pathogens’ such as Legionella and *Pseudomonas aeruginosa*.  These are naturally occurring bacteria that thrive in water systems.   ## Reducing the risk of Legionella and *Pseudomonas aeruginosa* This short presentation, delivered to [IIRSM ](https://www.iirsm.org/)provides detail on the background to Legionella and *Pseudomonas aeruginosa*, including those who are most susceptible, favourable conditions, and control strategies.    Looking at those possible opportunities that allow them to thrive within a water system and identifications of three key stakeholders that can impact on quality of water within the systems allowing these waterborne pathogens to establish in the first place and how they can easily be spread further and affect patients.    [![New call-to-action](https://no-cache.hubspot.com/cta/default/2896031/30cae303-224d-4299-9a43-10e08bb0888e.png)](https://cta-redirect.hubspot.com/cta/redirect/2896031/30cae303-224d-4299-9a43-10e08bb0888e)   With knowledge on the ‘Chain of Causation’ and some simple ‘dos’ and ‘don'ts’ will allow you to appreciate how they can assist with improved water safety.  To support this video, here are also some additional blogs you may find useful: - [Controlling the Chain of Infection](https://www.waterhygienecentre.com/blog/controlling-the-chain-of-infection) - [Water Safety and Legionella Training for Infection Prevention and Control](https://www.waterhygienecentre.com/blog/legionella-training-ipc) - [The Hidden Dangers in Hospital Water Systems](https://www.waterhygienecentre.com/blog/dangers-in-healthcare-water-system)   Feel free to reach out if you have any questions about the issues mentioned above or if you would like to [consult with one of our experts on water hygiene.](https://www.waterhygienecentre.com/contact) Editor’s Note: The information provided in this blog is correct as of the date of original publication – May 2026. © Water Hygiene Centre 2026  Click on the image above to view the full recording. [![New Call-to-action](https://no-cache.hubspot.com/cta/default/2896031/ba3583be-f15a-4dcf-973b-e071ac813d2d.png)](https://cta-redirect.hubspot.com/cta/redirect/2896031/ba3583be-f15a-4dcf-973b-e071ac813d2d) #### About the author #### [Water Hygiene Centre](https://www.waterhygienecentre.com/academy/author/water-hygiene-centre) The Water Hygiene Centre was established in 2009 to address the lack of independent water hygiene consultancy within the industry. From our humble beginnings, we have established ourselves as a market leader, helping clients identify and minimise the risk of waterborne contamination and disease, whilst improving compliance performance. ### Recent News ### [Watch Our Free Webinar: Water Safety Group (WSG) Explained](https://www.waterhygienecentre.com/academy/water-safety-group-webinar) by [Water Hygiene Centre](https://www.waterhygienecentre.com/academy/author/water-hygiene-centre), on 02-06-2026 Whether you're establishing a Water Safety Group (WSG) for the first time or reviewing your existing arrangements, this free webinar provides practical guidance to help your organisation strengthen... [Read More](https://www.waterhygienecentre.com/academy/water-safety-group-webinar) ### [IWFM Safe Water Management for Facilities Managers](https://www.waterhygienecentre.com/academy/iwfm-safe-water-management) by [Water Hygiene Centre](https://www.waterhygienecentre.com/academy/author/water-hygiene-centre), on 01-10-2025 Your tap water should be refreshing, not a breeding ground for harmful bacteria. Legionella and Pseudomonas aeruginosa could be lurking in your water systems, putting vulnerable individuals at risk. [Read More](https://www.waterhygienecentre.com/academy/iwfm-safe-water-management) ##### Share your thoughts ### Subscribe to our weekly email updates [![New call-to-action](https://no-cache.hubspot.com/cta/default/2896031/a09ebb17-596b-42dd-b32b-de5b8408a5c4.png)](https://cta-redirect.hubspot.com/cta/redirect/2896031/a09ebb17-596b-42dd-b32b-de5b8408a5c4) **About** **Services** **Training** **Knowledge Spa** [![Water-Hygiene-Centre-Logo1](https://www.waterhygienecentre.com/hs-fs/hubfs/WaterHygieneCentre-2019/Images/Water-Hygiene-Centre-Logo1.jpg?width=241&height=86&name=Water-Hygiene-Centre-Logo1.jpg "Water-Hygiene-Centre-Logo1")](https://www.waterhygienecentre.com/) ### Connect with us - [![Facebook](https://www.waterhygienecentre.com/hubfs/WaterHygieneCentre-2019/Images/facebook.png "Water Hygiene Centre on Facebook")](https://www.facebook.com/WaterHygieneCentre/) - [![LinkedIn](https://www.waterhygienecentre.com/hubfs/WaterHygieneCentre-2019/Images/linkedin.png "Water Hygiene Centre on LinkedIn")](https://www.linkedin.com/company/water-hygiene-centre/) - [![YouTube](https://www.waterhygienecentre.com/hubfs/WaterHygieneCentre-2019/Images/youtube.png "Water Hygiene Centre on YouTube")](https://www.youtube.com/channel/UCFc94KlCXe3HNXT-uXuBd8w)                                                                             © Copyright 2026. 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