UV light-based decontamination: an effective and fast way for disinfection of endoscopes in otorhinolaryngology?

Reprocessing of endoscopes becomes increasingly complex, due to rising demands of hygiene. Established methods are often expensive/time-consuming. Recent studies suggest beneficial aspects of disinfection by UV light. In this study we analyzed the efficiency of UV light disinfection of rigid otorhinolaryngological endoscopes.

After mechanical pre-cleaning, the endoscopes were decontaminated for 25 s in the D25 using Impelux™ UV C light technology (UV Smart B.V., Delft, The Netherlands). First, the surface contact samples were taken from 50 used endoscopes to evaluate the bacterial load. Additionally, surface contact samples were taken from further 50 used endoscopes after reprocessing with the D25. Another 50 endoscopes were tested on protein residuals. Furthermore, the absolute effectiveness of the D25 was tested on 50 test bodies (RAMS) with a standardized contamination of 10⁷ colony-forming units (CFU) of Enterococcus faecium.

The used endoscopes showed a high bacterial contamination with an average value of 66.908 (± 239.215) CFU. After reprocessing, only a minimal contamination on 10% (n = 5) of the endoscopes with a mean value of 0.12 CFU (± 0.39) was found, resulting in a log-5 reduction in a clinical environment. The documented bacteria were components of the normal skin flora. All tested endoscopes were practically protein-free (< 1 μg). Furthermore, the average absolute germ reduction of the D25 was about 10⁶ CFU on the tested RAMS.

The D25 UV light system seems to be an effective device for the reprocessing of rigid ORL endoscopes, and therefore, might be suitable for the usage in clinical practice on site.