Disinfection strategies for CPE in hospital water systems

Ahead of the next IPC Partners journal club (which you can register for here), I’ve taken an in depth look at the paper I’ll be covering from the Journal of Hospital Infection which you can read here.

Why did I choose this article?

I have been fascinated by the role of water in the transmission of healthcare associated infections (HAIs), as well as the role of disinfection to control outbreaks and attempt to eliminate reservoirs (including biofilms) in water systems. Disinfection of water systems is also something I’ve actively been involved in researching. Recently I led a study looking at the role of continuous UV-C on bacterial contamination in handwash basins.

This scoping review attracted my attention as I am aware of the different technologies and strategies for disinfection of water systems but there still seems to be a lot of variability in the reported success of the different options.

Methods

A scoping review was undertaken, in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) and the Extension for Scoping Reviews (PRISMA-ScR) standards. Of 1,188 records screened, 22 met inclusion criteria and thematic analysis categorised findings into chemical, physical and integrative strategies which included both proactive water management strategies and reactive interventions during known contamination or outbreaks. Studies addressing surface or air disinfection, non-healthcare settings and non-CPE bacteria were all excluded.

Key findings

• Water outlets, drains and sink traps consistently acted as long-term reservoirs for CPE.
• Point-of-use filtration offered reliable short-term protection.
• Chemical disinfection showed variable efficacy depending on implementation. Chemical disinfection agents included sodium hypochlorite, hydrogen peroxide, acetic acid and quaternary ammonium compounds.
• Physical and mechanical disinfection showed promise with evidence for steam cleaning, mechanical modifications and source removal (i.e. water free) in reducing outbreaks and colonisation of CPE.
• Integrative strategies combining disinfection, infrastructural upgrades, healthcare staff training and IPC policies were most effective
• Recolonisation after interventions was common, highlighting the need for sustained strategies.
• Novel disinfection approaches including the use of nanoparticles, bacteriophages and UV-C light have shown promise in published literature.

Points for discussion

• How do we standardise testing and evaluating efficacy of disinfectants used for water systems? Particularly against biofilms.
• Is there a role for continuous disinfectant dosing? If so, is this safe?
• Is there a way to more effectively monitor biofilm build up of CPE (and other Gram negative organisms) in water systems?
• How do we ensure we continue to innovate in this space to provide new technologies and solutions to keep water systems safe?

What this means for IPC

• Early detection and ongoing monitoring remain essential.
• Engineering-led solutions are often required to remove persistent biofilm reservoirs.
• Point-of-use filtration can offer short-term protection in high‑risk areas.
• Coordination between estates and IPC teams is critical for sustainable control.
• If possible water safety planning must be embedded into routine operations rather than delivered reactively.

Conclusion

The paper suggests  that CPE control in hospital water systems cannot rely on standalone interventions and there is no one size fits all to keep water systems safe. As research grows in the area more evidence will support informed decision making to keep the water system safe, however I believe a unified approach is years away.