Why This Matters:
- CPE are priority AMR threats: Carbapenemase producing Enterobacterales (CPE) are resistant to last line β lactams and associated with high morbidity, mortality, and transmission risk in healthcare settings. Hospital plumbing and water fixtures have been identified as environmental reservoirs that can lead to patient colonization and infection.
- Biofilms complicate control: CPE establish biofilms within drains, sink traps, and shower outlets, protecting organisms from conventional disinfectants and facilitating persistent reservoirs.
- Infection prevention integration needed: Broader infection prevention and control (IPC) practices must be implemented rather than relying solely on one type of disinfectant or single intervention.
Key Findings: In their scoping review of 22 studies (2014–2024) on disinfection and environmental control strategies targeting CPE in hospitals, Ali et al. organized the available evidence into three broad strategy classes1:
1. Chemical Disinfection: Single chemical interventions often fail against biofilm-associated CPE in hospital water systems. Sustained reductions are most consistently achieved when chemical disinfection is integrated with physical interventions (plumbing modifications, steam cleaning, and drain covers) and complementary infection prevention and control (IPC) practices. Classes reviewed included:
- Oxidizing agents: Sodium hypochlorite (3 studies) and hydrogen peroxide (1 study) reduce bacterial loads but are short-lived in effect; efficacy is limited by biofilms, sink type, and organic load. Frequent or foam-based applications improve outcomes.
- Organic acids: Acetic acid (3 outbreak studies) provides more sustained reductions when applied regularly, highlighting its utility in persistent contamination scenarios.
- Quaternary ammonium compounds: 0.5% Glucoprotamin (1 study) demonstrated effectiveness under controlled protocols; however, standardisation of application (e.g., concentration, contact time) is necessary to achieve consistent results.
2. Physical and Infrastructure Measures: Structural interventions are effective but often resource-intensive, requiring facility investment and IPC planning. Measures reviewed included:
- Steam cleaning: steam disinfection of sink outlets and drains reduced CPE presence significantly in some case reports (1 study).
- Drain covers and plumbing modifications: Physical barriers and structural changes (2 studies) can curtail the spread of contamination, reduce splash dispersion, and limit microbial regrowth niches.
- Plumbing upgrades/sink removal: Replacing or redesigning contaminated fixtures (2 studies) or removing water sources entirely (3 studies) can disrupt environmental reservoirs and significantly reduce CPE recovery rates.
3. Integrated Strategies: A multidisciplinary control approach—spanning chemical, physical, and procedural interventions aligned with IPC principles—offers the most robust outcomes reported to date. Emerging technologies such as ultraviolet (UV) irradiation and biofilm-targeting foams are highlighted as promising adjuncts, though evidence remains preliminary.
Bigger Picture: This scoping review consolidates fragmented evidence and underscores that no single strategy on its own consistently eliminates CPE from hospital water systems. Instead, effective control appears to rely on a combination of tailored disinfection, infrastructure modification, and IPC workflow integration. Biofilm presence remains a formidable barrier against disinfection and must be explicitly addressed in future interventions and guidelines.
References:
- Ali et al. 2025. A Scoping Review of Disinfection Strategies for Carbapenemase Producing Enterobacterales in Hospital Water Systems. The Journal of Hospital Infection.
