In-use tests of disinfectants

Area of Science:

• Microbiology
• Hospital Infection Control
• Public Health

Background:

• Disinfectant efficacy is crucial for preventing hospital-acquired infections.
• Standardized in-use testing methods are needed to ensure disinfectant quality in clinical settings.
• Previous evaluations of disinfectant testing methods have yielded varied results.

Purpose of the Study:

• To compare the efficacy of three different in-use disinfectant testing methods.
• To evaluate the suitability of these methods for routine use in hospital laboratories.
• To assess the quality control of disinfectants in Danish hospitals.

Main Methods:

• In-use testing of 400 disinfectant samples (aldehyde and phenolic solutions) from 11 Danish hospitals.
• Application of three testing methods: Kelsey-Maurer test, membrane filtration technique, and a standardized challenge test.
• Analysis of results for concordance and identification of inefficient samples.

Main Results:

• Complete accordance was observed between the Kelsey-Maurer test and membrane filtration.
• The standardized challenge test identified a slightly higher number of inefficient disinfectant samples.
• Approximately 3% of all samples failed the tests, with 10% failure rate for initial samples, indicating educational opportunities.

Conclusions:

• Established methods like Kelsey-Maurer and membrane filtration are suitable for routine hospital laboratory use.
• A standardized challenge test offers a more sensitive approach to detecting disinfectant failures.
• In-use disinfectant testing is valuable for hospital infection control policies and ensuring disinfectant efficacy.