- Design
- Exploratory, single-centre, prospective randomised surveillance study
- Population
- 222 reprocessing episodes of patient-used gastrointestinal endoscopes
- Primary outcome
- Surveillance culture success after automated reprocessing
- Effect
- 90.5% acidic electrolysed water vs 95.9% peracetic acid; risk difference −5.4 points (95% CI −14.6 to 3.2)
A single Japanese centre randomised 222 episodes of reprocessing used upper and lower gastrointestinal endoscopes to one of three automated disinfectants after standard bedside pre-cleaning and manual cleaning: strongly acidic electrolysed water, ozonated water, or peracetic acid.
Surveillance cultures passed (20 colony-forming units or fewer at every sampled site, with no indicator organisms) in 90.5% with acidic electrolysed water, 95.9% with ozonated water and 95.9% with peracetic acid. Against peracetic acid, the difference was −5.4 percentage points for acidic electrolysed water (95% CI −14.6 to 3.2) and zero for ozonated water. Repeated failures clustered in one physical endoscope.
The authors frame this as quality-assurance data, not evidence about infection risk. For infection prevention teams, the practical lessons are that functional-water systems were not shown to match peracetic acid on a tight margin, and that surveillance should track individual scopes, because one scope can account for a run of failures.
- Track surveillance culture results by individual endoscope, not only by reprocessing system.
- Withdraw and inspect a scope that fails surveillance more than once.
- Treat functional-water disinfection as not yet shown equivalent to peracetic acid.
- Keep manual cleaning standards high; automated reprocessing depends on it.
Why it matters
Prospective comparisons of disinfectant systems under routine conditions are scarce, and this one flags a gap.
Don't overread it
Exploratory, single-centre and measured by culture, not by patient infections.
The statistics, in plain English
The confidence interval for acidic electrolysed water (−14.6 to 3.2 percentage points) is wide and includes both a real shortfall and no difference. The non-inferiority analyses were added after the fact, which makes them weaker than a pre-planned test.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for infectious diseases, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free