Validating sporicidal efficacy of ultrasound probe high-level disinfection devices in clinical settings
Discuss this preprint
Start a discussion What are Sciety discussions?Listed in
This article is not in any list yet, why not save it to one of your lists.Abstract
Introduction
In accordance with AS5369:2023 and ISO 15883-1:2024 Standards, in-field validation testing of automated high-level disinfection (HLD) devices in clinical settings is necessary to qualify their performance. Responding to reports that some ultraviolet-C (UV-C) devices were failing to achieve sporicidal efficacy during routine in-field validation, we evaluated the sporicidal efficacy of these devices via a performance qualification test.
Methods
Sporicidal efficacy was assessed using commercially available stainless steel biological indicators (BIs) inoculated with 10 6 Geobacillus stearothermophilus spores (ATCC ® 7953). BIs were clamped in top and bottom locations inside chambers of devices [UV-C light-emitting diode (LED), UV-C lamp and hydrogen peroxide (H 2 O 2 ) mist]. BI test conditions included packaged, unwrapped and non-flamed and unwrapped and flame sterilised on the clamped coupon end. Results were evaluated on a pass (no growth) or fail (growth) basis.
Results
The results showed that the UV-C LED device failed to inactivate spores in all tested positions and conditions (n=18). The UV-C lamp device passed 2/6 tests in the flamed condition but failed all other tests (n=12). The H 2 O 2 mist system passed all tests, inactivating spores for all conditions and chamber positions (n=18).
Conclusion
Our findings show that despite claiming sporicidal efficacy, the UV-C devices both failed in-field validation tests using bacterial endospores. These results indicate that the UV-C devices were not sporicidal in these tests. The H 2 O 2 mist device was the only system in this study that passed all tests, achieving sporicidal efficacy.
