Fluid retention in endoscopes: A real-world study on drying effectiveness.

BACKGROUND: Outbreaks linked to inadequate endoscope drying have infected numerous patients, and current standards and guidelines recommend at least 10 minutes of forced air for drying channels. This study evaluated a new forced-air drying system (FADS) for endoscopes. METHODS: Drying was assessed using droplet detection cards; visual inspection of air/water connectors, suction connectors, and distal ends; and borescope examinations of endoscope interiors. Assessments were performed after automated endoscope reprocessor (AER) alcohol flush and air purge cycles and after 10-minute FADS cycles. RESULTS: Researchers evaluated drying during encounters with 22 gastroscopes and 20 colonoscopes. After default AER alcohol and air purge cycles, 100% (42/42) of endoscopes were still wet. Substantial fluid emerged from distal ends during the first 15 seconds of the FADS cycle, and droplets also emerged from air/water and suction connectors. Following FADS cycle completion, 100% (42/42) were dry, with no retained fluid detected by any of the assessment methods. CONCLUSIONS: Multiple endoscope ports and channels remained wet after AER cycles intended to aid in drying but were dry after the FADS cycle. This study reinforced the need to evaluate the effectiveness of current drying practices and illustrated the use of practical tools in a real-world setting.

Feasibility and efficacy of newly developed eco-friendly, automatic washer for endoscope using electrolyzed alkaline and acidic water.

INTRODUCTION: As well as preventing nosocomial and healthcare-associated infections, a reliable and eco-friendly washer for medical equipment would also be safe for the global environment. The aim of this study was to evaluate the efficacy of a newly developed automatic washing system (Nano-washer) that uses electrolyzed water and ultrasonication without detergent for washing endoscopes. METHODS: Patients who underwent laparoscopic lobectomy or laparoscopic colectomy at Nagasaki University between 2018 and 2022 were included. A total of 60 cases of endoscope use were collected and classified according to endoscope washing method into the Nano-washer group (using no detergent) (n = 40) and the manual washing group (n = 20). Protein and bacterial residues were measured before and after washing, using absorbance spectrometry and 16S rRNA polymerase chain reaction. The effectiveness of protein and bacterial removal and endoscope surface damage after washing were compared under specular vision between the groups. RESULTS: Nano-washer did not use detergent unlike manual washing. There was no difference in demographic or clinical characteristics between the groups except for the presence of comorbidities in the lobectomy group (Nano-washer, 85%; manual washing, 40%, P = .031). Compared with the manual washing group, residual protein levels in the Nano-washer group were significantly reduced after washing (lobectomy, 0.956 mg/mL vs 0.016 mg/mL, P < .001; colectomy, 0.144 mg/mL vs 0.002 mg/mL, P = .008). Nano-washer group showed a significant reduction in bacteria between before and after lobectomy (9437 copies/cm2 vs 4612 copies/cm2 , P = .024). CONCLUSION: Nano-washer is a promising, effective, and eco-friendly automatic washing device that is safer and more efficient than manual washing.

Evaluation of two detergent-disinfectants and a detergent on a Klebsiella pneumoniae biofilm formed within Tygon tubes.

BACKGROUND: Transmission of infections via contaminated endoscopes is a common problem. Manual cleaning, using at least a detergent, is an important step in endoscope processing and should be performed as soon as possible to avoid drying of organic residues that might interfere with high-level disinfection and promote biofilm formation. AIM: To assess the efficacy of two detergent-disinfectants, enzymatic and non-enzymatic, and of an enzymatic detergent used during the manual cleaning against a Klebsiella pneumoniae biofilm. METHODS: A 24 h biofilm statically formed in a Tygon tube was exposed to detergent-disinfectants at 20 °C and 35 °C for 10 mn, and to enzymatic detergent at 45 °C for 60 mn. The logarithmic reduction in bacteria in the Tygon tube and the number of bacteria in the product supernatant were calculated. FINDINGS: Biofilm formation was reproducible between assays. After exposure to detergent-disinfectants, the logarithmic reduction was between 6.32 and 6.71 log10 cfu/cm2 in the Tygon tubes. No bacteria were found in their supernatants. Results in the detergent-disinfectant group were not affected by the exposure temperature or the addition of enzymes. No decrease in the bacterial load was observed in the Tygon tubes after exposure to the enzymatic detergent. Bacteria were found in its supernatant. CONCLUSION: These results show the importance of the choice of products used during the manual cleaning phase. They also show the potential benefit of combining detergent and disinfectant activity to decrease the bacterial load during the manual cleaning step of endoscope processing.

[A systematic analysis of nosocomial outbreaks of nosocomial infections after gastrointestinal endoscopy]. / Eine systematische Analyse nosokomialer Ausbrüche von Infektionskrankheiten in der gastrointestinalen Endoskopie.

Esophagogastroduodenoscopy (EGD), endoscopic retrograde cholangiopancreatography (ERCP) and colonoscopy (CLN) come with a potential risk of pathogen transmission. Unfortunately, up to now data on the causes and the distribution of pathogens is rather sparse.We performed a systematic review of the medical literature using the Worldwide Outbreak Database, the PubMed, and Embase. We then checked so-retrieved articles for potential sources of the outbreak, the spectrum of pathogens, the attack rates, mortality and infection control measures.In total 73 outbreaks (EGD: 24, ERCP: 42; CLN: 7) got included. The corresponding attack rates were 3.5%, 7.1% and 12.8% and mortality rates were 6.3%, 12.7% and 10.0% respectively. EGD was highly associated with transmission of enterobacteria including a large proportion of multi-drug resistant strains. ERCP led primarily to transmission of non-fermenting gram-negative rods. The most frequent cause was human failure during reprocessing regardless of the type of endoscope.Staff working in the field of endoscopy should always be aware of the possibility of pathogen transmission in order to detect and terminate those events at the early most time point. Furthermore, proper ongoing education of staff involved in the reprocessing and maintenance of endoscopes is crucial. Single-use devices may be an alternative option and lower the risk of pathogen transmission, but on the downside may also increase costs and waste.

Efficacy of high-level disinfection of endoscopes contaminated with Streptococcus equi subspecies equi with 2 different disinfectants.

BACKGROUND: Prevention of spread of Streptococcus equi subspecies equi (S. equi) after an outbreak is best accomplished by endoscopic lavage of the guttural pouch, with samples tested by culture and real time, quantitative polymerase chain reaction (qPCR). Disinfection of endoscopes must eliminate bacteria and DNA to avoid false diagnosis of carrier horses of S. equi. HYPOTHESIS/OBJECTIVES: Compare failure rates of disinfection of endoscopes contaminated with S. equi using 2 disinfectants (accelerated hydrogen peroxide [AHP] or ortho-phthalaldehyde [OPA]). The null hypothesis was that there would be no difference between the AHP and OPA products (based on culture and qPCR results) after disinfection. METHODS: Endoscopes contaminated with S. equi were disinfected using AHP, OPA or water (control). Samples were collected before and after disinfection and submitted for detection of S. equi by culture and qPCR. Using a multivariable logistic regression model-adjusted probability, with endoscope and day as controlled variables, the probability of an endoscope being qPCR-positive was determined. RESULTS: After disinfection, all endoscopes were culture-negative (0%). However, the raw unadjusted qPCR data were positive for 33% AHP, 73% OPA, and 71% control samples. The model-adjusted probability of being qPCR-positive after AHP disinfection was lower (0.31; 95% confidence interval [CI], -0.03-0.64) compared to OPA (0.81; 95% CI, 0.55-1.06), and control (0.72; 95% CI, 0.41-1.04). CONCLUSION AND CLINICAL IMPORTANCE: Disinfection using the AHP product resulted in significantly lower probability of endoscopes being qPCR-positive compared to the OPA product and control.

Significant increased bacterial contamination with endoscope overnight and weekend storage times.

BACKGROUND AND AIM: Forced-air drying (FAD) cabinets are recommended for storage of reprocessed endoscopes, but financial constraints prevent their universal application. The study aimed to determine bacterial contamination in flexible gastroscopes (FG) channels after storage, in a cabinet with filtered air and UV lights, but without FAD. METHODS: Eight FG in clinical use in an endoscopy service of a large Brazilian hospital were sampled: immediately "Time zero" (N = 50), 12 h "Time 1" (N = 25), and 60 h "Time 2" (N = 25) after reprocessing. Following a flush-brush-flush of channels, 40-mL sterile water and 3 cm of the brush were collected. Each sample was divided, filtered onto two 0.22-µm membranes, and incubated in media without or with disinfectant neutralizer. Automated method was used for identification and antibiotic resistance test of isolated bacteria. RESULTS: Bacterial contamination in times "1" and "2" was 5.9 and 16.1 times greater than that of "Time zero," respectively. Number of positive cultures in media with and without neutralizer was similar at times "1" and "2," while media with neutralizer produced more positive cultures at "Time zero." Most bacteria isolated at "Time 2" were Gram-negative rods (52.3%) and showed resistance to one or more antibiotics (65%). CONCLUSION: Bacterial contamination was detected on reprocessed FG stored in non-FAD cabinets overnight (12 h) and increased with longer storage time (60 h). The contamination source is likely to be bacteria in biofilm which multiply in the absence of FAD. Evidence-based criteria should be available for storage time according to the cabinet available.

A review of Spaulding's classification system for effective cleaning, disinfection and sterilization of reusable medical devices: Viewed through a modern-day lens that will inform and enable future sustainability.

Despite advances in medicine and innovations in many underpinning fields including disease prevention and control, the Spaulding classification system, originally proposed in 1957, remains widely used for defining the disinfection and sterilization of contaminated re-usable medical devices and surgical instruments. Screening PubMed and Scopus databases using a PRISMA guiding framework generated 272 relevant publications that were used in this review. Findings revealed that there is a need to evolve how medical devices are designed, and processed by cleaning, disinfection (and/or sterilization) to mitigate patient risks, including acquiring an infection. This Spaulding Classification remains in use as it is logical, easily applied and understood by users (microbiologists, epidemiologists, manufacturers, industry) and by regulators. However, substantial changes have occurred over the past 65 years that challenge interpretation and application of this system that includes inter alia emergence of new pathogens (viruses, mycobacteria, protozoa, fungi), a greater understanding of innate and adaptive microbial tolerance to disinfection, toxicity risks, increased number of vulnerable patients and associated patient procedures, and greater complexity in design and use of medical devices. Common cited examples include endoscopes that enable non- or minimal invasive procedures but are highly sophisticated with various types of materials (polymers, electronic components etc), long narrow channels, right angle and heat-sensitive components and various accessories (e.g., values) that can be contaminated with high levels of microbial bioburden and patient tissues after use. Contaminated flexible duodenoscopes have been a source of several significant infection outbreaks, where at least 9 reported cases were caused by multidrug resistant organisms [MDROs] with no obvious breach in processing detected. Despite this, there is evidence of the lack of attention to cleaning and maintenance of these devices and associated equipment. Over the last few decades there is increasing genomic evidence of innate and adaptive resistance to chemical disinfectant methods along with adaptive tolerance to environmental stresses. To reduce these risks, it has been proposed to elevate classification of higher-risk flexible endoscopes (such as duodenoscopes) from semi-critical [contact with mucous membrane and intact skin] to critical use [contact with sterile tissue and blood] that entails a transition to using low-temperature sterilization modalities instead of routinely using high-level disinfection; thus, increasing the margin of safety for endoscope processing. This timely review addresses important issues surrounding use of the Spaulding classification system to meet modern-day needs. It specifically addresses the need for automated, robust cleaning and drying methods combined with using real-time monitoring of device processing. There is a need to understand entire end-to-end processing of devices instead of adopting silo approaches that in the future will be informed by artificial intelligence and deep-learning/machine learning. For example, combinational solutions that address the formation of complex biofilms that harbour pathogenic and opportunistic microorganisms on the surfaces of processed devices. Emerging trends are addressed including future sustainability for the medical devices sector that can be enabled via a new Quintuple Helix Hub approach that combines academia, industry, healthcare, regulators, and society to unlock real world solutions.

Alcohol flush does not aid in endoscope channel drying but may serve as an adjunctive microbiocidal measure: A new take on an old assumption.

BACKGROUND: Alcohol is perceived to aid flexible endoscope channel drying, however we previously showed alcohol increased the time required to dry some channels with forced air versus water alone. Yet, alcohol may prevent microorganism outgrowth during storage. Drying endoscope channels has been shown to prevent outgrowth, but it is unknown if incomplete drying (<10 µL remaining) provides similar protection. METHODS: Endoscope channel test articles were used to determine the efficacy of 70%-30% alcohol flush for prevention of Pseudomonas aeruginosa outgrowth and drying efficiency. For non-alcohol flushed channels, the impact of forced air drying on outgrowth of P. aeruginosa was determined. RESULTS: Alcohol flush (70%-30%) prevented outgrowth with little to no recovery of P. aeruginosa during ambient storage. 70% alcohol increased channel drying time by 1.5 or 3-fold compared to 50% alcohol or water, respectively. Forced air drying of non-alcohol flushed channels greatly reduced the initial contamination level and prevented outgrowth. Incomplete drying of contaminated channels was akin to no application of forced air. Applying forced air for more time than necessary to remove residual liquid did not completely eliminate the low level recovery of P. aeruginosa. CONCLUSIONS: Flushing with reduced concentrations of alcohol may provide a strategy to prevent microbial outgrowth while reducing drying time.

Disinfection of otorhinolaryngological endoscopes with electrolyzed acid water: A cross-sectional and multicenter study.

Glutaraldehyde, a germicide for reprocessing endoscopes that is important for hygiene in the clinic, might be hazardous to humans. Electrolyzed acid water (EAW) has a broad anti-microbial spectrum and safety profile and might be a glutaraldehyde alternative. We sought to assess EAW disinfection of flexible endoscopes in clinical otorhinolaryngological settings and its in vitro inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and bacteria commonly isolated in otorhinolaryngology. Ninety endoscopes were tested for bacterial contamination before and after endoscope disinfection with EAW. The species and strains of bacteria were studied. The in vitro inactivation of bacteria and SARS-CoV-2 by EAW was investigated to determine the efficacy of endoscope disinfection. More than 20 colony-forming units of bacteria at one or more sampling sites were detected in 75/90 microbiological cultures of samples from clinically used endoscopes (83.3%). The most common genus detected was Staphylococcus followed by Cutibacterium and Corynebacterium at all sites including the ears, noses, and throats. In the in vitro study, more than 107 CFU/mL of all bacterial species examined were reduced to below the detection limit (<10 CFU/mL) within 30 s after contact with EAW. When SARS-CoV-2 was treated with a 99-fold volume of EAW, the initial viral titer (> 105 PFU) was decreased to less than 5 PFU. Effective inactivation of SARS-CoV-2 was also observed with a 19:1 ratio of EAW to the virus. EAW effectively reprocessed flexible endoscopes contributing to infection control in medical institutions in the era of the coronavirus disease 2019 pandemic.

Cleaning of in-hospital flexible endoscopes: Limitations and challenges.

OBJECTIVE: to analyze the cleaning process of gastroscopes, colonoscopes and duodenoscopes in eight in-hospital health services. METHOD: a cross-sectional study conducted with 22 endoscopes (eight gastroscopes, eight colonoscopes and six duodenoscopes), and microbiological analysis of 60 samples of air/water channels (all endoscopes) and elevator (duodenoscopes), in addition to protein testing. Descriptive statistics with calculation of frequencies and central tendency measures was used in data analysis. RESULTS: the processing of 22 endoscopes was monitored with microbiological analysis for 60 channels. In the pre-cleaning procedure, in 82.3% (14/17) of the devices, gauze was used in cleaning the insertion tube. Incomplete immersion of the endoscope in detergent solution occurred in 72.3% (17/22) of the cases, and in 63.6% (14/22) there was no standardization of filling-in of the channels. Friction of the biopsy channel was not performed in 13.6% (3/22) of the devices. In the microbiological analysis, 25% (7/32) of the samples from the stored endoscopes were positive for microbial growth (from 2x101 to 9.5x104 CFU/mL), while after processing, contamination was 32% (9/28). Protein residues in the elevator channel were detected in 33% of duodenoscopes. CONCLUSION: the results indicate important gaps in the stages of pre-cleaning and cleaning of endoscopes that, associated with presence of protein residues and growth of microorganisms of epidemiological importance, indicate limitations in safety of the processing procedures, which can compromise the disinfection processes and, consequently, their safe use among patients subjected to such tests.

Biofilm accumulation in new flexible gastroscope channels in clinical use.

OBJECTIVE: Assess the accumulation of protein and biofilm on the inner surfaces of new flexible gastroscope (FG) channels after 30 and 60 days of patient use and full reprocessing. DESIGN: Clinical use study of biofilm accumulation in FG channels. SETTING: Endoscopy service of a public hospital. METHODS: First, we tested an FG in clinical use before the implementation of a revised reprocessing protocol (phase 1 baseline; n = 1). After replacement of the channels by new ones and the implementation of the protocol, 3 FGs were tested after 30 days of clinical use (phase 2; n = 3) and 3 FGs were tested after 60 days of clinical use (phase 3; n = 3), and the same FGs were tested in phase 2 and 3. Their biopsy, air, water, and air/water junction channels were removed and subjected to protein testing (n = 21), bacteriological culture (n = 21), and scanning electron microscopy (SEM) (n = 28). Air-water junction channels fragments were subjected to SEM only. RESULTS: For the FGs, the average number of uses and reprocessing cycles was 60 times. Extensive biofilm was detected in air, water, and air-water junction channels (n = 18 of 28). All channels (28 of 28) showed residual matter, and structural damage was identified in most of them (20 of 28). Residual protein was detected in the air and water channels of all FG evaluated (phases 1-3), except for 1 air channel from phase 2. Bacteria were recovered from 8 of 21 channels, most air or water channels. CONCLUSIONS: The short time before damage and biofilm accumulation in the channels was evident and suggests that improving the endoscope design is necessary. Better reprocessing methods and channel maintenance are needed.

A Novel Flocked Swab Protocol Proves to Be an Effective Method for Culturing Elevator-Containing Endoscopes.

BACKGROUND: The challenging disinfection process for the elevator mechanism on duodenoscopes and linear echoendoscopes has been identified as a source of clinically significant bacterial transmission. Despite increased awareness, there continues to be a lack of definitive guidelines for bacterial culturing protocols for elevator-containing endoscopes. AIMS: To compare two different prospective bacterial surveillance protocols for duodenoscopes and linear echoendoscopes with regard to accuracy, efficiency, and cost. METHODS: Consecutive duodenoscopes and linear echoendoscopes used at a single tertiary care center were reprocessed following hospital and manufacturer guidelines, dried using an automatic endoscope-drying machine, and hung overnight in an upright position. Following reprocessing, culture samples were sequentially obtained from each endoscope using two methods, first, the brush protocol followed immediately by the swab protocol. RESULTS: A total of 532 primary cultures were collected from 17 duodenoscopes and eight linear echoendoscopes. Of these, 266 cultures gathered using the brush protocol were negative, while 266 cultures gathered using the swab protocol resulted in three positive cultures (1.1%). Positive cultures showed Enterobacter cloacae and Klebsiella pneumoniae from one duodenoscope and two linear echoendoscopes. Yearly, the brush protocol amounts to approximately 520 nursing hours, and the swab protocol takes an estimated 42 nursing hours. Annually, the swab protocol could save over $26,500 and 478 nursing hours. CONCLUSIONS: The proposed swab protocol was superior to the brush protocol when evaluating the presence of residual bacteria on elevator-containing endoscopes following reprocessing and saves cost and nursing hours.

Cleaning of in-hospital flexible endoscopes: Limitations and challenges / Limpeza de endoscópios flexíveis intra-hospitalares: limitações e desafios / Limpieza de endoscopios flexibles intrahospitalarios: limitaciones y desafíos

Abstract Objective: to analyze the cleaning process of gastroscopes, colonoscopes and duodenoscopes in eight in-hospital health services. Method: a cross-sectional study conducted with 22 endoscopes (eight gastroscopes, eight colonoscopes and six duodenoscopes), and microbiological analysis of 60 samples of air/water channels (all endoscopes) and elevator (duodenoscopes), in addition to protein testing. Descriptive statistics with calculation of frequencies and central tendency measures was used in data analysis. Results: the processing of 22 endoscopes was monitored with microbiological analysis for 60 channels. In the pre-cleaning procedure, in 82.3% (14/17) of the devices, gauze was used in cleaning the insertion tube. Incomplete immersion of the endoscope in detergent solution occurred in 72.3% (17/22) of the cases, and in 63.6% (14/22) there was no standardization of filling-in of the channels. Friction of the biopsy channel was not performed in 13.6% (3/22) of the devices. In the microbiological analysis, 25% (7/32) of the samples from the stored endoscopes were positive for microbial growth (from 2x101 to 9.5x104 CFU/mL), while after processing, contamination was 32% (9/28). Protein residues in the elevator channel were detected in 33% of duodenoscopes. Conclusion: the results indicate important gaps in the stages of pre-cleaning and cleaning of endoscopes that, associated with presence of protein residues and growth of microorganisms of epidemiological importance, indicate limitations in safety of the processing procedures, which can compromise the disinfection processes and, consequently, their safe use among patients subjected to such tests.

Resumo Objetivo: analisar o processo de limpeza de gastroscópios, colonoscópios e duodenoscópios em oito serviços de saúde intra-hospitalar. Método: estudo transversal com 22 endoscópios, sendo oito gastroscópios, oito colonoscópios e seis duodenoscópios, e análise microbiológica de 60 amostras dos canais de ar/água (todos os endoscópios) e elevador (duodenoscópios), além de teste de proteína. Na análise dos dados, utilizou-se estatística descritiva, com cálculo de frequências e medidas de tendência central. Resultados: o processamento de 22 endoscópios foi acompanhado com análise microbiológica de 60 canais. Na pré-limpeza, em 82,3% (14/17) dos equipamentos, foi utilizada gaze na limpeza do tubo de inserção. A imersão incompleta do endoscópio em solução detergente ocorreu em 72,3% (17/22) dos casos, e em 63,6% (14/22) não havia padronização do preenchimento dos canais. A fricção do canal de biópsia não foi realizada em 13,6% (3/22) dos equipamentos. Na análise microbiológica, 25% (7/32) das amostras dos endoscópios armazenados foram positivas para crescimento microbiano (2x101 a 9,5x104 UFC/mL), enquanto após o processamento, a contaminação foi de 32% (9/28). Resíduos de proteína no canal do elevador foram detectados em 33% dos duodenoscópios. Conclusão: os resultados apontam lacunas importantes nas etapas de pré-limpeza e limpeza dos endoscópios que, associadas à presença de resíduos de proteína e ao crescimento de microrganismo de importância epidemiológica, sinalizam limitações na segurança do processamento, que podem comprometer os processos de desinfecção e consequentemente seu uso seguro entre pacientes submetidos a tais exames.

Resumen Objetivo: analizar el proceso de limpieza de gastroscopios, colonoscopios y duodenoscopios en ocho servicios de salud intrahospitalarios. Método: estudio transversal con 22 endoscopios, de los cuales ocho eran gastroscopios, ocho colonoscopios y seis duodenoscopios, y análisis microbiológico de 60 muestras de los canales de aire/agua (todos los endoscopios) y elevador (duodenoscopios), además de prueba de proteínas. En el análisis de los datos se utilizó estadística descriptiva, con cálculo de frecuencias y medidas de tendencia central. Resultados: el procesamiento de los 22 endoscopios fue monitoreado con el análisis microbiológico de 60 canales. En la prelimpieza, en el 82,3% (14/17) de los equipos se utilizó gasa para limpiar el tubo de inserción. En el 72,3% (17/22) de los casos la inmersión del endoscopio en solución detergente fue incompleta y en el 63,6% (14/22) no hubo estandarización del llenado de los canales. La fricción del canal de biopsia no se realizó en el 13,6% (3/22) de los equipos. En el análisis microbiológico, el 25% (7/32) de las muestras endoscópicas almacenadas dio positivo para crecimiento microbiano (2x101 a 9,5x104 UFC/ml), mientras que después del procesamiento, la contaminación fue del 32% (9/28). Se detectaron residuos de proteína en el canal elevador en el 33% de los duodenoscopios. Conclusión: los resultados indican que hay importantes lagunas en las etapas de prelimpieza y limpieza de los endoscopios que, junto con la presencia de residuos de proteínas y del crecimiento de microorganismos de importancia epidemiológica, indican limitaciones en la seguridad del procesamiento, que pueden comprometer los procesos de desinfección y, por ende, el uso seguro en los pacientes que se someten a esos procedimientos.

Development of a checklist as self-assessment tool to evaluate the reprocessing of endoscopic instruments in an Italian teaching hospital.

OBJECTIVE: The present study aims to develop a checklist, as a self-assessment tool, for evaluating all the items involved in the endoscope reprocessing that could be useful for the improvement and/or development of a safety endoscope reprocessing system. MATERIALS AND METHODS: A three-step modified Delphi method, with an embedded qualitative component, was adopted to develop the checklist. According to it, corrective actions were performed before its further re-administration. Contextually, the microbiological surveillance of the endoscopes and of the wash disinfector machine was carried out. RESULTS: Five areas were included in the checklist. After the 1st checklist application, only one of three wards reached the excellent scores in all the items. The other two wards showed an improvement in the Traceability and Endoscope Reprocessing areas after corrective actions. The McNemar's test reported significant difference in the proportion of satisfactory results before and after the 1st and 2nd checklist application. The microbiological surveillance, conducted after the 1st administration, showed unsatisfactory results for the 2 bronchoscopes available in the Intensive Care Unit and for 2 automated endoscope reprocessors. The analysis performed after the 2nd administration showed good results. CONCLUSIONS: The periodic administration of the checklist is functional for a self-assessment of quality reprocessing procedures carried out in the large endoscopic services and in the wards occasionally providing those services, according to the good practice guidelines and for any corrective actions to increase the safety.

'Secondary biofilms' could cause failure of peracetic acid high-level disinfection of endoscopes.

INTRODUCTION: The reduced susceptibility of biofilms to disinfectants presents a challenge to the successful reprocessing of medical equipment. This study examined the effect of residual biomass remaining after previous disinfection with peracetic acid (PAA) on the tolerance of subsequent mature Pseudomonas aeruginosa biofilms to PAA. The effect of enzymatic degradation of specific components of the extracellular polymeric substance (EPS) of P. aeruginosa biofilm on the effectiveness of PAA disinfection was also evaluated. METHODS: The susceptibility of biofilm grown on the biomass of PAA-killed biofilm to PAA was compared with the PAA susceptibility of biofilm grown in wells of a 24-well plate by evaluating their viability using the plate count assay. The effect of PAA on biofilm biomass was measured using crystal violet quantification of total biofilm biomass, while its effect on the polysaccharide and protein components of biofilm EPS was quantified using the phenol-sulphuric acid assay or Bradford assay, respectively. A confocal microscope was used to visualize the distribution of living and dead cells in biofilms grown on residual biofilm biomass. FINDINGS: The presence of residual biomass from previously disinfected biofilms significantly enhanced the tolerance of subsequent biofilms. A 96-h-old 'secondary biofilm' formed on disinfected biomass survived PAA concentrations of 4000 ppm, which exceeds the concentrations used in practice for high-level disinfection. CONCLUSION: These observations indicate that, under certain circumstances, recolonization of residual EPS can cause failure of disinfection of medical equipment such as endoscopes, and emphasizes the importance of cleaning endoscopes prior to disinfection.

Introduction to Transmission of Infection: Potential Agents Transmitted by Endoscopy.

Pathogen contamination of endoscopes depends on pathogen factors, surface factors, and environmental conditions. The most common pathogens associated with transmission and infections associated with gastrointestinal endoscope contamination are Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa. Biofilm production together with disruption to device surfaces play an outsized role in the risk of contamination. Sampling schemes are limited by these factors, and further developments are needed to improve the accuracy of sampling.

Quality Systems Approach for Endoscope Reprocessing: You Don't Know What You Don't Know!

Several factors affect the efficacy of endoscope reprocessing, including human factors, inadequate cleaning, simethicone residuals, moisture in channels during storage, and biofilm or buildup biofilm formation. These factors all contribute to contamination of patient-ready endoscopes that may contribute to transmission of microorganisms resulting in infection and/or colonization. This article reviews monitoring as part of a quality management system that includes manual cleaning, dry storage, and culture to detect endoscope contamination. The published data for rapid tests that detect organic residuals and adenosine triphosphate to monitor manual cleaning are reviewed.

Novel Algorithms for Reprocessing, Drying and Storing Endoscopes.

After outbreaks of duodenoscope-transmitted infection with multidrug-resistant organisms, it has become clear that institutions must optimize their endoscope reprocessing programs. Standard endoscope reprocessing practices may not represent the ideal approach for preventing transmission of infection related to endoscopy. We discuss multiple approaches to enhance and optimize reprocessing, drying, and storage of standard duodenoscopes. The optimal enhanced duodenoscope reprocessing modality remains to be determined. Acknowledging the challenges and limitations in effectively reprocessing duodenoscopes, the FDA issued a safety communiqué recommending transitioning to either single use disposable duodenoscopes or duodenoscopes with innovative designs that allow more effective reprocessing.

Contribution of usage to endoscope working channel damage and bacterial contamination.

BACKGROUND: Biofilm formation has been shown to be associated with damaged areas of endoscope channels. It was hypothesized that the passage of instruments and brushes through endoscope channels during procedures and cleaning contributes to channel damage, bacterial attachment and biofilm formation. AIM: To compare surface roughness and bacterial attachment in used and new endoscope channels in vivo and in vitro. METHODS: Surface roughness of 10 clinically used (retired) and seven new colonoscope biopsy channels was analysed by a surface profiler. For the in-vitro study, a flexible endoscope biopsy forceps was passed repeatedly through a curved 3.0-mm-diameter Teflon tube 100, 200 and 500 times. Atomic force microscopy was used to determine the degree of inner surface damage. The number of Escherichia coli or Enterococcus faecium attached to the inner surface of the new Teflon tube and the tube with 500 forceps passes in 1 h at 37oC was determined by culture. RESULTS: The average surface roughness of the used biopsy channels was found to be 1.5 times greater than that of the new biopsy channels (P=0.03). Surface roughness of Teflon tubes with 100, 200 and 500 forceps passes was 1.05-, 1.12- and 3.2-fold (P=0.025) greater than the roughness of the new Teflon tubes, respectively. The number of E. coli and E. faecium attached to Teflon tubes with 500 forceps passes was 2.9-fold (P=0.021) and 4.3-fold (P=0.004) higher compared with the number of E. coli and E. faecium attached to the new Teflon tubes, respectively. CONCLUSION: An association was found between endoscope usage with damage to the biopsy channel and increased bacterial attachment.

Klebsiella pneumoniae survival and regrowth in endoscope channel biofilm exposed to glutaraldehyde and desiccation.

Biofilm in endoscopes is a major problem that can result in failure of disinfection. We studied the survival of K. pneumoniae in a biofilm formed on endoscope tubes subjected to combined chemical and physical stresses. We monitored bacterial survival in the biofilm after the action of 1% and 2% GTA either immediately or after 15 days of desiccation and described the ability of surviving bacteria to recolonize endoscope tubing in a dynamic model. There were surviving bacteria after 5-min exposure to 2% and 1% GTA. The percentage of survivors after 2% and 1% GTA was greater when the GTA treatment was performed after 15 days of prior desiccation of the biofilm. The survivors were able to recolonize and reform biofilm on abiotic surfaces probably because of the survival of persisters in a viable but non-culturable state in the biofilm. Our findings emphasize that the current guidelines on endoscope reprocessing should be strictly followed but that once constituted the biofilm in endoscope tubing will be very difficult to eradicate with present practices.