Introduction
In otorhinolaryngology (ORL), flexible endoscopes without a working
channel (FEs) are used to examine the nasal cavity, pharynx and larynx.
FEs are frequently used and thus reprocessed several times a day.
Previous research demonstrated that contamination with secretions, blood
and microorganisms after use can be extensive(1). Inadequate
reprocessing of endoscopes is considered the most important factor of
contamination from endoscopy procedures, possibly resulting in outbreaks
of health-care-associated infections(2). Therefore, thorough
reprocessing of FEs is critical for limiting pathogen transmission and
reducing infections.
To determine the strategy for sterilization or disinfection of a
specific medical devices, the level of disinfection is determined. There
are three disinfection levels: high, intermediate and low-level
disinfection. Each disinfection level can be distinguished from one
another based on the specific marker or indicator microorganisms that
each can or cannot destroy. According to Spaulding’s classification
scheme, FEs are considered semi-critical medical devices and require
high-level disinfection(3).
Several standard guidelines for reprocessing endoscopes have been
developed by several professional organizations, such as the European
Society for Gastrointestinal Endoscopy(ESGE), the American Society for
Gastrointestinal Endoscopy(ASGE), the Healthcare Infection Control
Practices Advisory Committee(HICPAC) and the Dutch Flexible Endoscopes
Cleaning and Disinfection Steering Committee(SFERD) or guidelines are
provided by the manufacturer of the FEs(4-7). No international standard
has been implemented and the methods used are often time-consuming. This
could lead to longer waiting times for patients, or additional costs,
because the long reprocessing times require more FEs in inventory. In
addition, large amounts of water and chemicals are used. Disinfection
with ultraviolet light(UVL) could be an alternative method.
UVL can be divided into three groups depending on the length of their
bands: A(315-400 nm), B(280-315 nm) and C(100-280 nm)(8). UVL group
C(UV-C) is known to be the most harmful to living organisms, with peak
efficiency at 254nm(8).
Previous research has shown that UVL disinfection of medical surfaces
can be highly effective in reducing microorganisms, such as Clostridium
difficile, Methicillin-resistant Staphylococcus aureus (MRSA),
biofilm-forming bacteria and fungal spores(9-12). UV-C light
disinfection for ORL endoscopes showed a bacterial reduction of
106 Colony Forming Units(CFUs) for rigid endoscopes
and a 107 CFU reduction for FEs(13, 14).
The current reprocessing method for FEs is done using water and
chemicals with the Endoscope Washer Disinfector (EWD). However, this
process is time-consuming and should therefore be improved. UV-C light
disinfection has shown to be a promising tool for surface and endoscope
disinfection in previous research. The goal of this study was to
investigate the CFU reduction on contaminated FEs without a working
channel after UV-C light disinfection, compared to the current
disinfection method with the EWD.