Retrospective analysis of P. aeruginosa persistence in hospital water systems among pediatric patients in EnglandOne hospital water system kept bacteria alive for eight years

medRxiv Published April 25, 2026 Study authors: Sheth, E.; Case, L.; Shaw, F.; Dwyer, N.; Poland, J.; Wan, Y.; Larru, B. DOI ↗ Editorial oversight: Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

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Key Takeaway

Note the difficulty in eradicating P. aeruginosa in hospital water systems and the need for continuous controls.

This retrospective analysis examines environmental and clinical P. aeruginosa isolates collected from taps, sinks, showers, baths, and various clinical specimens at a 330-bed NHS hospital in England. The study period spanned from July 2016 to September 2024, analyzing a total of 457 P. aeruginosa isolates. The primary outcome assessed the persistence of P. aeruginosa in the water system and potential transmission between environmental and clinical sources.

The analysis identified 56 isolate clusters. Of these, 19 of 56 clusters, representing 34%, contained at least one invasive isolate. One cluster, designated Cluster 1, demonstrated significant persistence, spanning the entire study duration from July 2016 to September 2024 and involving n=20 isolates.

The authors acknowledge limitations, specifically the difficulty in detecting and eradicating P. aeruginosa in hospital water and wastewater systems. No adverse events or discontinuations were reported. The practice relevance underscores the necessity for continuous rigorous water system controls to develop effective strategies for water-safe care, rather than inferring causation or overstating eradication capabilities based on these observational data.

Imagine a hospital water system that acts like a hidden reservoir for dangerous germs. A new look at data from a large children's hospital in England reveals exactly how long these bacteria can survive. Over eight years, from July 2016 to September 2024, researchers tracked 457 samples of P. aeruginosa. This germ is known for causing serious infections in sick patients, especially those with weak immune systems.

The team found 56 groups of identical bacteria. Surprisingly, 34% of these groups included strains that caused invasive infections. One specific group of bacteria stayed in the water system for the entire eight-year period. This shows that water systems can act as a long-term home for these germs, allowing them to move from the environment into patients.

This study highlights a major challenge for hospital safety. It is very difficult to detect and completely remove these bacteria once they are in the water pipes. The findings reinforce the urgent need for strict, continuous controls over hospital water systems to keep patients safe.

What this means for you:

Hospital water systems can harbor dangerous bacteria for years, making strict ongoing controls essential for patient safety.

Study Details

Sample sizen = 20

EvidenceLevel 5

PublishedApr 2026

View Original Abstract ↓

Background Pseudomonas aeruginosa is a major cause of healthcare-associated infections in paediatric settings, where its persistence in moist environments such as hospital water and wastewater systems poses a particular risk to neonates and immunocompromised children. Aim The aim of this study was to showcase the long-term survival and transmission of P. aeruginosa in a large tertiary children's hospital in England which is crucial to develop strategies for water-safe care. Methods Environmental P. aeruginosa isolates were collected from taps, sinks, showers, and baths in augmented care areas of a 330-bed tertiary children's hospital built to NHS water-safety standards. Clinical isolates were classified as invasive (blood, cerebrospinal fluid, and bronchoalveolar lavage) or non-invasive (respiratory, urine, ear, abdominal, and rectal surveillance). Variable number tandem repeat (VNTR) profiles and metadata were extracted from PDF reports, de-identified, deduplicated, and curated using Python and R. Findings This retrospective study analysed nine-locus VNTR profiles of 457 P. aeruginosa isolates submitted to the UK Health Security Agency from a large tertiary children's hospital, identifying 56 isolate clusters (each with [≥]2 isolates), of which 19 (34%) contained at least one invasive isolate. The most persistent cluster (Cluster 1, n=20) spanned from July 2016 to September 2024, containing environmental and clinical (invasive and non-invasive) isolates. Conclusion These findings demonstrate long-term persistence of certain genotypes and temporal overlap between environmental and clinical isolates, highlighting the difficulty in detecting and eradicating P. aeruginosa in hospital water and wastewater systems and reinforcing the need for continuous rigorous water system controls.

Retrospective analysis of P. aeruginosa persistence in hospital water systems among pediatric patients in EnglandOne hospital water system kept bacteria alive for eight years

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Retrospective analysis of P. aeruginosa persistence in hospital water systems among pediatric patients in EnglandOne hospital water system kept bacteria alive for eight years

Study Details

Intrawound tobramycin plus vancomycin did not reduce deep infection risk compared with vancomycin alone in high-risk tibial fractures

Adding Antibiotics to Bone Surgery Didn't Lower Infection Risk

Clinical research that matters. Delivered to your inbox.

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