Case 6 Fight Against Nosocomial Infections
Decontamination and microbiological surveillance of endoscopes Prof. dr. Isabel Leroux-Roels Laboratory of Medical Microbiology & Infection Control Team UZ Gent In collaboration with Dr. Thomas Vanzieleghem ONE Life bemedtech Symposium - Brussels - 11/10/2017
Overview Presentation of the study performed at the Endoscopy Unit of UZ Gent (Cattoir et al. ICHE 2017) Sneakpreview of a multicenter trial (case study) in Endoscopy Units of Belgian hospitals (2018) Further discussion and questions during the network drink 3
Background Spaulding classification Endoscopy-related infections Incidence: 1/1,8 million procedures Medical device most frequently linked to healthcare associated outbreaks Probably only the tip of the iceberg (MDRO) Explanations Complex design Development of a biofilm inside the channels of the endoscope Use of defective equipment Failure to comply with established cleaning and disinfection guidelines 4
Rationale of the study Microbiological surveillance of endoscopes could allow for early detection of endoscope contamination, thereby preventing cross-transmission and infections of patients If microbiological surveillance of endoscopes is done, how should it be performed? Which method gives the highest microbiological yield? Many different guidelines (US and European), with lack of agreement on the sampling technique, frequency, incubation conditions and acceptance criteria 5
Overview of guidelines on microbial surveillance of endoscopes Guideline Year Frequency of routine samples HGR Belgium 2010 annually SFERD Netherlands 2014 none Sampling technique flushing with sterile saline flushing with sterile saline +brush Sampling Volume 20 ml per channel 20 ml per channel Volume used for culture Culture medium Incubation temperature Duration of incubation 20 ml / / /? Criterion of acceptance 20 ml / / / < 20 CFU/channel CTINILS France 2007 annually flushing with sterile tensioactive fluid 100-200 ml 100-200 ml non-selective agar 30 C 5days < 25 CFU; no indicator MO BSG UK 2008 none / / / / / / / ESGE-ESGENA Europe GESA-GENCA Australia MACID Canada ASGE-SHEA US 2008 4x/year - annualy 2010 2000 depending on the type of scope none or 2-3x/year APIC US 2000 none flushing with sterile saline flushing with sterile water or saline + brush flushing with sterile water + brush 20 ml per channel 10 ml per channel 1 ml 100 µl (after centrifug ation) 10 ml 100 µl non-selective agar 2 blood agars blood agar Sabouraud agar 30 C 2days 28 C 35 C 37 C 30 C 7days 2days 5days 2011 none / / / / / / / flushing with sterile saline + brush MO, microorganisms; CFU, Colony Forming Units; /, not mentioned;?, unclear. / / / / / < 20 CFU/mL; no indicator MO each unit should set its own threshold < 20 CFU/0,1 ml no vegetative bacteria
Aim of the study Comparison of different endoscope sampling techniques (sensitivity) In an endoscope model (laboratory setting) In various types of flexible heat-sensitive endoscopes (in real life conditions) Cattoir et al. Infect Control Hosp Epidemiol 2017; 38: 1062-69 7
Materials and methods (1/2) Setting: Endoscopy unit University Hospital Ghent 42 endoscope 13 000 procedures/year, high turnover, limited storage tim Method: manual cleaning (Aniozyme, Olympus standard cleaning brush), high level disinfection in an automated endoscope reprocessor (Olympus ETD3, glutaraldehyde) 80 endoscopes were sampled 20 gastroscopes 20 colonoscopies 10 duodenoscopes and 10 echo-endoscopes 20 bronchoscopes Sampling techniques 1. flushing with 100mL of physiological saline (=100PHYS) 2. flush-brush-flush with 100mL of physiological saline and a PULL THRU TM brush (=100PHYS+PT) Cattoir et al. Infect Control Hosp Epidemiol 2017; 38: 1062-69 8
Materials and methods (2/2) ATP (in duplicate) Culture Aquasnap TM Total test SystemSURE Plus luminometer Relative Light Units (RLU) 100 µl directly on TSA Fitration-membrane on TSA Incubation for 7 days at 30 C CFU count + Maldi TOF identification (detection of indicator MO) Acceptance criteria < 25 CFU/endoscope AND absence of indicator MO (French criteria) Indicator MO: S. aureus, Enterobacteriaceae, Pseudomonas aeruginosa, Pseudomonas spp., Acinetobacter spp., Stenotrophomonas maltophilia, Candida spp. Cattoir et al. Infect Control Hosp Epidemiol 2017; 38: 1062-69 9
Results Culture results obtained from endoscopic samples using 100PHYS and 100PHYS+PT sampling and results of negative controls 100PHYS+PT method yields statistically significantly higher CFU counts as compared to the 100 PHYS method, except for bronchoscopes 10
Results Culture 3 indicator MO with PHYS method, 2 with PHYS + PT Higher number of endoscopes classified as unacceptable using PHYS +PT (p = 0,03) No changes in classification ((un)acceptable) after 48 hours of incubation ATP No statistically significant difference in ATP results (p=0,25) Cattoir et al. Infect Control Hosp Epidemiol 2017; 38: 1062-69 11
Results ATP values of samples classified as unacceptable (> 25 CFU or presence of indicator MO) were higher compared to those classified as acceptable (p = 0,002) Subgroup analysis: only true for PHYS+PT method (p = 0,001), not for PHYS only method (p = 0,9) Cattoir et al. Infect Control Hosp Epidemiol 2017; 38: 1062-69 12
Conclusions Addition of a PULL THRU TM brush to the endoscope sampling procedure increases the yield of microbial surveillance culture. The added value of ATP needs to be confirmed in future studies. In our study, all endoscopes were classified correctly as (un)acceptable at 48 hours of incubation. However, given the concern about slow-growing microorganisms, it seems prudent to extend the incubation period to 7 days. For the future, there is a need for internationally recognized acceptance criteria to enable assessment of the clinical relevance of more sensitive sampling techniques. Cattoir et al. Infect Control Hosp Epidemiol 2017; 38: 1062-69 13
What s next? Research question: Can we decrease the level of microbial contamination of endoscopes by applying a bundle of interventions, thereby reducing the risk of transmission to patients? 14
Bundled approach Implementation of a new protocol for endoscope reprocessing based on latest literature and guidelines Use of enzymatic detergents manufactured by ONELife that specifically dissolve biofilms (enzimed Prevent for routine cleaning and enziqure for curative treatment) Implementation of a sampling method with improved yield and less false negative results (Cattoir et al. 2017) Audits to document compliance with reprocessing guidelines Take the lead in endoscope safety : Meet us at OneLife booth to discuss this proposal 15
Thank you! Dr. Lien Cattoir Dr. Thomas Vanzieleghem, R&D manager, ONE Life & other co-authors of the manuscript Lab technicians of the Microbiology lab UZ Gent Collaborators of the Endocopy Unit UZ Gent 16
Limitations comments Limited sample size (2 x 40 endoscopes) Interval between sampling with both techniques Endoscope age Non-sterile brushes and ATP tests No neutralizer Other incubation conditions to evaluate Cattoir et al. Infect Control Hosp Epidemiol 2017; 38: 1062-69 17
Call for action more info at table with case 6 Fight Against Nosocomial Infections Symposium 18