Multi-society guideline for reprocessing flexible gastrointestinal endoscopes. Society for Healthcare Epidemiology of America

Mechanical deformation of elastomer medical devices can enable microbial surface colonization

Elastomers such as silicone are common in medical devices (catheters, prosthetic implants, endoscopes), but they remain prone to microbial colonization and biofilm infections. For the first time, our work shows that rates of microbial surface attachment to polydimethylsiloxane (PDMS) silicone can be significantly affected by mechanical deformation. For a section of bent commercial catheter tubing, bacteria (P. aeruginosa) show a strong preference for the 'convex' side compared to the 'concave' side, by a factor of 4.2. Further testing of cast PDMS materials in bending only showed a significant difference for samples that were manually wiped (damaged) beforehand (1.75 × 10⁴ and 6.02 × 10³ cells/mm² on the convex and concave sides, respectively). We demonstrate that surface microcracks in elastomers are opened under tensile stress (convex bending) to become 'activated' as sites for microbial colonization. This work demonstrates that the high elastic limit of elastomers enables these microcracks to reversibly open and close, as 'dynamic defects'. Commercial catheters have relatively high surface roughness inherent to manufacturing, but we show that even manual wiping of newly-cast PDMS is sufficient to generate surface microcracks. We consider the implication for medical devices that feature sustained, surgical, or cyclic deformation, in which localized tensile conditions may expose these surface defects to opportunistic microbes. As a result, our work showcases serious potential problems in the widespread usage and development of elastomers in medical devices.

How effective are the alcohol flush and drying cycles of automated endoscope reprocessors? Stripped endoscope model

BACKGROUND

Effective drying of the internal channels of endoscopes is essential to prevent the growth of water-borne pathogens and to assure adequate sterilization with vaporized hydrogen peroxide or ethylene oxide. The aim of this study was to evaluate the dryness of endoscopes after a routine disinfection process in an automated endoscope reprocessor.

METHODS

Stripped endoscopes (SE) that allow for visual inspection of the inside channels were reprocessed per protocol in a large urban medical center, with a 3-minute or 10-minute air flush following reprocessing. SE was hung and observed for any water within the channels after reprocessing and after a week of ambient storage. Ready-for-use endoscopes were also randomly spot-checked for moisture visually and with moisture detection paper.

RESULTS

All SE were grossly wet after HLD with a 3-minute air flush, despite alcohol flush and drying cycle. The 10-minute air flush was effective at drying the biopsy/suction channel, but not the air/water channels. Hanging had limited effect, being most effective in the biopsy/suction channels. Of the 77 ready-for-use respiratory and gastrointestinal endoscopes assessed, 37 (48.1%) showed evidence of retained moisture.

CONCLUSIONS

Air flush cycles commonly used in the final steps of automated endoscope reprocessing may not adequately dry endoscope channels, particularly the narrower diameter air/water channels. An extended 10-minute air flush appears effective at drying the larger biopsy/suction channel, but has limited effect on the air/water channels.

Accreditation program for gastrointestinal endoscopes reprocessing in Italy: An on-site survey

Background and study aims  Endoscope reprocessing has been associated with a variable failure rate. Our aim was to present an overview on current practices for reprocessing in Italian facilities and discuss the principle critical points. Methods  In 2014 the Italian Society for Digestive Diseases implemented an accreditation program in collaboration with an independent organization for certification and with the Italian Association for Endoscopy Technical Operators. During a 1-day site visit of the endoscopy center, two endoscopists, one nurse, and the representative of the certification body evaluated the endoscope reprocessing. Results  As of July 1, 2020, 28 endoscopy centers had been accredited. Ten centers are completing the measures to correct deficiencies found at the visit. Three centers withdrew from the program. The accreditation program has found variations between the various centers, confirming the poor compliance with guidelines. Major deviations from the standards, established by the model before the site visit according to national and international guidelines, concerned instrument cleaning (44.7 % of the centers), instrument storage (23.7 %), and microbiological tests (31.6 %). Conclusions  Our overview demonstrated the lack of many reprocessing phases, which are important to prevent endoscopy-associated infections. Accreditation can achieve a transformation in quality and safety of reprocessing with the Italian centrally-led approach.

Duodenoscope-associated infections: a review

Flexible digestive endoscopes are used for the management of various conditions with hundreds of thousands of therapeutic procedures performed worldwide each year. Duodenoscopes are indispensable tools for the delivery of minimally invasive vital care of numerous pancreaticobiliary disorders. Despite the fact that nosocomial infections after endoscopic retrograde cholangiopancreatography (ERCP) have always been among the most frequently cited postprocedural complications, recent emergence of duodenoscope-transmitted multiple drug-resistant bacterial infections has led to intense research and debate yet with no clearly delineated solution. Duodenoscope-transmitted nosocomial infections have become one of the most visible topics in the recent literature. Hundreds of high-impact articles have therefore been published in the last decade. This review article discusses how such infections were seen in the past and what is the current situation in both research and practice and thus tries to solve some of the unanswered questions for the future. With the persistence of nosocomial infections despite strict adherence to both manufacturer-issued reprocessing protocols and international guidelines and regulations, an urgent and proper microbiologically driven common action is needed for controlling such nosocomial worldwide threat.

Worldwide practices on flexible endoscope reprocessing

Background

Endoscopy related infections represent an important threat for healthcare systems worldwide. Recent outbreaks of infections with multidrug resistant micro-organisms have highlighted the problems of contaminated endoscopes. Endoscopes at highest risk for contamination have intricate mechanisms, multiple internal channels and narrow lumens that are especially problematic to clean. In light of raised awareness about the necessity for meticulous reprocessing of all types of endoscopes, a call for international collaboration is needed. An overview is presented on current practices for endoscope reprocessing in facilities worldwide.

Method

An electronic survey was developed and disseminated by the International Society for Antimicrobials and Chemotherapy. The survey consisted of 50 questions aimed at assessing the reprocessing of flexible endoscopes internationally. It covered three core elements: stakeholder involvement, assessment of perceived risks, and reprocessing process.

Results

The survey received a total of 165 completed responses from 39 countries. It is evident that most facilities, 82% (n = 136), have a standard operating procedure. There is, however a lot of variation within the flexible endoscope reprocessing practices observed. The need for regular training and education of reprocessing practitioners were identified by 50% (n = 83) of the respondents as main concerns that need to be addressed in order to increase patient safety in endoscope reprocessing procedures.

Conclusion

This international survey on current flexible endoscope reprocessing identified a large variation for reprocessing practices among different health care facilities/countries. A standardised education and training programme with a competency assessment is essential to prevent reprocessing lapses and improve patient safety.

Electronic supplementary material

The online version of this article (10.1186/s13756-018-0446-6) contains supplementary material, which is available to authorized users.

Potential testing of reprocessing procedures by real-time polymerase chain reaction: A multicenter study of colonoscopy devices

BACKGROUND

Reprocessing of endoscopes is key to preventing cross-infection after colonoscopy. Culture-based methods are recommended for monitoring, but alternative and rapid approaches are needed to improve surveillance and reduce turnover times. A molecular strategy based on detection of residual traces from gut microbiota was developed and tested using a multicenter survey.

METHODS

A simplified sampling and DNA extraction protocol using nylon-tipped flocked swabs was optimized. A multiplex real-time polymerase chain reaction (PCR) test was developed that targeted 6 bacteria genes that were amplified in 3 mixes. The method was validated by interlaboratory tests involving 5 reference laboratories. Colonoscopy devices (n = 111) were sampled in 10 Italian hospitals. Culture-based microbiology and metagenomic tests were performed to verify PCR data.

RESULTS

The sampling method was easily applied in all 10 endoscopy units and the optimized DNA extraction and amplification protocol was successfully performed by all of the involved laboratories. This PCR-based method allowed identification of both contaminated (n = 59) and fully reprocessed endoscopes (n = 52) with high sensibility (98%) and specificity (98%), within 3-4 hours, in contrast to the 24-72 hours needed for a classic microbiology test. Results were confirmed by next-generation sequencing and classic microbiology.

CONCLUSIONS

A novel approach for monitoring reprocessing of colonoscopy devices was developed and successfully applied in a multicenter survey. The general principle of tracing biological fluids through microflora DNA amplification was successfully applied and may represent a promising approach for hospital hygiene.

Occupational risk for Legionella infection among dental healthcare workers: meta-analysis in occupational epidemiology

OBJECTIVE

The occupational risk for Legionella infection among dental healthcare workers (DHCWs) is conjectured because of the risk of routine inhalation of potentially contaminated aerosols produced by the dental instruments. Nevertheless, occupational epidemiology studies are contrasting. This meta-analysis assessed the level of scientific evidence regarding the relative occupational risk for Legionella infection among DHCWs.

METHODS

Literature search was performed without time and language restrictions, using broad data banks (PubMed, Scopus, Web of Science, GOOGLE Scholar) and generic keywords ('legionella' AND 'dent*'). Analytical cross-sectional studies comparing prevalence of high serum Legionella antibody levels in DHCWs and occupationally unexposed individuals were considered. The relative occupational risk was assessed through prevalence ratio (PR) with 95% CI. Between-study heterogeneity was assessed (Cochran's Q test) and was used to choose the meta-analytic method. Study quality (modified Newcastle-Ottawa Scale) and publication bias (Begg and Mazumdar's test, Egger and colleagues' test, trim and fill R₀ method) were assessed formally and considered for the sensitivity analysis. Sensitivity analysis to study inclusion, subgroup analyses (dental staff categories; publication year, before vs after 1998, ie, 5 years after the release by the Centers for Disease Control and Prevention of the infection control guidelines in dental healthcare setting) were performed.

RESULTS

Seven studies were included (2232 DHCWs, 1172 occupationally unexposed individuals). No evidence of publication bias was detected. The pooled PR estimate was statistically non-significant at 95% level (1.7; 95% CI 0.8 to 3.2), study-quality adjustment did not change the PR considerably (PR, 1.5; 95% CI 0.5 to 4.1). PR was statistically significant before 1998 and no longer significant after 1998. Subgroup analysis according to DHCW categories was inconclusive.

CONCLUSIONS

There is no scientific evidence that DHCWs are at high occupational risk. The differences between former and recent studies could be due to different characteristics of municipal water systems and the infection control guideline dissemination.

Modifications of Pseudomonas aeruginosa cell envelope in the cystic fibrosis airway alters interactions with immune cells

Pseudomonas aeruginosa is a ubiquitous environmental organism and an opportunistic pathogen that causes chronic lung infections in the airways of cystic fibrosis (CF) patients as well as other immune-compromised individuals. During infection, P. aeruginosa enters the terminal bronchioles and alveoli and comes into contact with alveolar lining fluid (ALF), which contains homeostatic and antimicrobial hydrolytic activities, termed hydrolases. These hydrolases comprise an array of lipases, glycosidases, and proteases and thus, they have the potential to modify lipids, carbohydrates and proteins on the surface of invading microbes. Here we show that hydrolase levels between human ALF from healthy and CF patients differ. CF-ALF influences the P. aeruginosa cell wall by reducing the content of one of its major polysaccharides, Psl. This CF-ALF induced Psl reduction does not alter initial bacterial attachment to surfaces but reduces biofilm formation. Importantly, exposure of P. aeruginosa to CF-ALF drives the activation of neutrophils and triggers their oxidative response; thus, defining human CF-ALF as a new innate defense mechanism to control P. aeruginosa infection, but at the same time potentially adding to the chronic inflammatory state of the lung in CF patients.

Reprocessing and reuse of urological armamentarium: How correct are we!

Healthcare is expensive for a large proportion of the population in spite of high per capita income and good health insurance penetration. In an effort to reduce cost of the procedure, reprocessing of devices was started in the late 1970s. Reprocessing practice includes various measures such as proper cleaning, disinfection, and sterilization procedures. As reprocessing is aimed at reducing cost, there is a potential risk of compromising patient safety due to cross contamination after inadequate sterilization. There is also risk of performance alteration of urological reprocessed devices during sterilization/disinfection processing. Therefore, there is a need for formulating proper guidelines to decide methods of reprocessing for various urological equipment. There is also need to discuss the problematic areas that urologists face and to find their solutions. A PubMed search was made in September 2016, using key words "reprocessing of medical devices," "Single Use Devices," "methods of reprocessing of devices in clinical practice," "use of formalin chamber," "urological disposable sterilization," etc., After excluding duplicates, all English articles were reviewed by title and abstract. Full texts of selected articles were obtained, and these articles were cross-referenced to find any other related articles. All the articles were reviewed. A product can be reused if it can be economically reprocessed with validated protocols with preservation of its function. There is no reason to discard it after one use. This practice is useful for controlling economics of a urological case and to reduce the financial burden. Current Food and Drug Administration guidelines are stringent. The contamination described to test the sterilization process in the suggested guidelines actually does never exist in clinical practice. Therefore, new guidelines considering the clinical practice scenario are desirable.

Sterilization and Disinfection

Sterilization and disinfection are the basic components of hospital infection control activities. Every day, a number of hospitals are performing various surgical procedures. Even more number of invasive procedures are being performed in different health care facilities. The medical device or the surgical instrument that comes in contact with the sterile tissue or the mucus membrane of the patient during the various processes is associated with increased risk of introduction of pathogens into the patient's body. Moreover, there is chance of transmission of infection from patient to patient; from patient or to health care personnel, and vice versa; or from the environment to the patient through the improper sterilized or disinfected devices. Hence, medical personnel, laboratory people and the health care providers should have better knowledge regarding these techniques to prevent the spread of these pathogens.

Multi-omics analysis of niche specificity provides new insights into ecological adaptation in bacteria

Different lifestyles, ranging from a saprophyte to a pathogen, have been reported in bacteria of one species. Here, we performed genome-wide survey of the ecological adaptation in four Burkholderia seminalis strains, distinguished by their origin as part of the saprophytic microbial community of soil or water but also including human and plant pathogens. The results indicated that each strain is separated from the others by increased fitness in medium simulating its original niche corresponding to the difference between strains in metabolic capacities. Furthermore, strain-specific metabolism and niche survival was generally linked with genomic variants and niche-dependent differential expression of the corresponding genes. In particular, the importance of iron, trehalose and d-arabitol utilization was highlighted by the involvement of DNA-methylation and horizontal gene transfer in niche-adapted regulation of the corresponding operons based on the integrated analysis of our multi-omics data. Overall, our results provided insights of niche-specific adaptation in bacteria.

Infectious diseases linked to cross-contamination of flexible endoscopes

Flexible endoscopes are widely used to examine, diagnose, and treat medical disorders. While the risk of endoscopy-related transmission of infection is estimated to be very low, more health care-associated infections are related to contaminated endoscopes than to any other medical device. Flexible endoscopes can get highly contaminated with microorganisms, secretions and blood during use. The narrow lumens and multiple internal channels make the cleaning of flexible endoscopes a complex and difficult task. Despite the availability of international, national and local endoscope reprocessing guidelines, contamination and transmission of microorganisms continue to occur. These transmissions are mostly related to the use of defective equipment, endoscope reprocessing failures, and noncompliance with recommended guidelines. This article presents an overview of publications about case reports and outbreaks related to contamination of flexible endoscopes.

Results from a Large-Scale Epidemiologic Look-Back Investigation of Improperly Reprocessed Endoscopy Equipment

Objective.

To determine whether improper high-level disinfection practices during endoscopy procedures resulted in bloodborne viral infection transmission.

Design.

Retrospective cohort study.

Setting.

Four Veterans Affairs medical centers (VAMCs).

Patients.

Veterans who underwent colonoscopy and laryngoscopy (ear, nose, and throat [ENT]) procedures from 2003 to 2009.

Methods.

Patients were identified through electronic health record searches and serotested for human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV). Newly discovered case patients were linked to a potential source with known identical infection, whose procedure occurred no more than 1 day prior to the case patient's procedure. Viral genetic testing was performed for case/proximate pairs to determine relatedness.

Results.

Of 10,737 veterans who underwent endoscopy at 4 VAMCs, 9,879 patients agreed to viral testing. Of these, 90 patients were newly diagnosed with 1 or more viral bloodborne pathogens (BBPs). There were no case/proximate pairings found for patients with either HIV or HBV; 24 HCV case/proximate pairings were found, of which 7 case patients and 8 proximate patients had sufficient viral load for further genetic testing. Only 2 of these cases, both of whom underwent laryngoscopy, and their 4 proximates agreed to further testing. None of the 4 remaining proximate patients who underwent colonoscopy agreed to further testing. Mean genetic distance between the 2 case patients and 4 proximate patients ranged from 13.5% to 19.1%.

Conclusions.

Our investigation revealed that exposure to improperly reprocessed ENT endoscopes did not result in viral transmission in those patients who had viral genetic analysis performed. Any potential transmission of BBPs from colonoscopy remains unknown.

Results from a Large-Scale Epidemiologic Look-Back Investigation of Improperly Reprocessed Endoscopy Equipment

Objective.

To determine whether improper high-level disinfection practices during endoscopy procedures resulted in bloodborne viral infection transmission.

Design.

Retrospective cohort study.

Setting.

Four Veterans Affairs medical centers (VAMCs).

Patients.

Veterans who underwent colonoscopy and laryngoscopy (ear, nose, and throat [ENT]) procedures from 2003 to 2009.

Methods.

Patients were identified through electronic health record searches and serotested for human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV). Newly discovered case patients were linked to a potential source with known identical infection, whose procedure occurred no more than 1 day prior to the case patient's procedure. Viral genetic testing was performed for case/proximate pairs to determine relatedness.

Results.

Of 10,737 veterans who underwent endoscopy at 4 VAMCs, 9,879 patients agreed to viral testing. Of these, 90 patients were newly diagnosed with 1 or more viral bloodborne pathogens (BBPs). There were no case/proximate pairings found for patients with either HIV or HBV; 24 HCV case/proximate pairings were found, of which 7 case patients and 8 proximate patients had sufficient viral load for further genetic testing. Only 2 of these cases, both of whom underwent laryngoscopy, and their 4 proximates agreed to further testing. None of the 4 remaining proximate patients who underwent colonoscopy agreed to further testing. Mean genetic distance between the 2 case patients and 4 proximate patients ranged from 13.5% to 19.1%.

Conclusions.

Our investigation revealed that exposure to improperly reprocessed ENT endoscopes did not result in viral transmission in those patients who had viral genetic analysis performed. Any potential transmission of BBPs from colonoscopy remains unknown.

How to Assess Risk of Disease Transmission to Patients When There Is a Failure to Follow Recommended Disinfection and Sterilization Guidelines

Background.

Disinfection and sterilization are critical components of infection control. Unfortunately, breaches of disinfection and sterilization guidelines are not uncommon.

Objective.

To describe a method for evaluating a potential breach of guidelines for high-level disinfection and sterilization of medical devices.

Methods.

The appropriate scientific literature was reviewed to determine the frequency of failures of compliance. A risk assessment model was constructed.

Results.

A 14-step protocol was constructed to aid infection control professionals in the evaluation of potential disinfection and sterilization failures. In addition, a model is presented for aiding in determining how patients should be notified of the potential adverse event. Sample statements and letters are provided for communicating with the public and individual patients.

Conclusion.

Use of a protocol can guide an institution in managing potential disinfection and sterilization failures.

Transmission of infection by flexible gastrointestinal endoscopy and bronchoscopy

Flexible endoscopy is a widely used diagnostic and therapeutic procedure. Contaminated endoscopes are the medical devices frequently associated with outbreaks of health care-associated infections. Accurate reprocessing of flexible endoscopes involves cleaning and high-level disinfection followed by rinsing and drying before storage. Most contemporary flexible endoscopes cannot be heat sterilized and are designed with multiple channels, which are difficult to clean and disinfect. The ability of bacteria to form biofilms on the inner channel surfaces can contribute to failure of the decontamination process. Implementation of microbiological surveillance of endoscope reprocessing is appropriate to detect early colonization and biofilm formation in the endoscope and to prevent contamination and infection in patients after endoscopic procedures. This review presents an overview of the infections and cross-contaminations related to flexible gastrointestinal endoscopy and bronchoscopy and illustrates the impact of biofilm on endoscope reprocessing and postendoscopic infection.

Steps of reprocessing and equipments

With the increasing interest in endoscopy and the rising number of endoscopic examinations in hospitals, the importance of endoscopic reprocessing is also increasing. Cure facilities that are understaffed and ill-equipped are trying to cope with the problems of insufficient cleaning and high infection risks. To prevent endoscopy-associated infection, the endoscope cleaning, and disinfection guidelines prepared by the Korean Society of Gastrointestinal Endoscopy must be followed. In this review, the steps of endoscopic reprocessing and the equipments required in each step are discussed.

The role of biofilms in reprocessing medical devices

Biofilms are communities of microorganisms within extracellular polymeric material attached to surfaces. Within a biofilm, cells have some protection from drying and other stress factors in their environment, including antimicrobial agents. In this article, the challenges to medical device reprocessing posed by biofilms are addressed. Biofilm formation on reusable medical device surfaces is a risk that can be controlled. By ensuring prompt device cleaning and reprocessing either by high-level disinfection or sterilization and proper drying, biofilms will not have a chance to form. Reusable medical devices like flexible endoscopes that are promptly cleaned and disinfected, rinsed and dried pose little risk to patients.

Plumbing of hospital premises is a reservoir for opportunistically pathogenic microorganisms: a review

Several bacterial species that are natural inhabitants of potable water distribution system biofilms are opportunistic pathogens important to sensitive patients in healthcare facilities. Waterborne healthcare-associated infections (HAI) may occur during the many uses of potable water in the healthcare environment. Prevention of infection is made more challenging by lack of data on infection rate and gaps in understanding of the ecology, virulence, and infectious dose of these opportunistic pathogens. Some healthcare facilities have been successful in reducing infections by following current water safety guidelines. This review describes several infections, and remediation steps that have been implemented to reduce waterborne HAIs.

Development and validation of rapid use scope test strips to determine the efficacy of manual cleaning for flexible endoscope channels

BACKGROUND

Cleaning of flexible endoscopes is most commonly performed using manual methods that are often performed inadequately. The aim of this study was to validate the sample collection protocol and the Rapid Use Scope Test (RUST) and then assess its usefulness in clinical use.

METHODS

The benchmarks for adequate cleaning were protein <6.4 μg/cm(2), hemoglobin <2.2 μg/cm(2), and carbohydrate <1.2 μg/cm(2). Sample collection consisted of flushing 10 mL of sterile reverse osmosis water through the suction-biopsy port to the distal end. Validation of the RUST audit tool included simulated-use and in-use testing in 43 endoscopy clinics across Canada.

RESULTS

Simulated-use testing validated that improperly cleaned endoscopes that exceeded the cleaning benchmarks would be flagged by the RUST test. The clinical-use study indicated that 96.6% of 1,489 scope channels tested were RUST negative; however, 19% and 12% of elevator guide-wire channels and endoscopic retrograde colangiopancreatography channels, respectively, exceeded the benchmarks. The survey indicated that reprocessing personnel valued a rapid audit tool for assessing compliance with manual cleaning.

CONCLUSION

The validated RUST test provides health care users with a rapid audit tool for manual cleaning that can be integrated into the quality program in endoscopy.

Surveillance cultures of samples obtained from biopsy channels and automated endoscope reprocessors after high-level disinfection of gastrointestinal endoscopes

Background

The instrument channels of gastrointestinal (GI) endoscopes may be heavily contaminated with bacteria even after high-level disinfection (HLD). The British Society of Gastroenterology guidelines emphasize the benefits of manually brushing endoscope channels and using automated endoscope reprocessors (AERs) for disinfecting endoscopes. In this study, we aimed to assess the effectiveness of decontamination using reprocessors after HLD by comparing the cultured samples obtained from biopsy channels (BCs) of GI endoscopes and the internal surfaces of AERs.

Methods

We conducted a 5-year prospective study. Every month random consecutive sampling was carried out after a complete reprocessing cycle; 420 rinse and swabs samples were collected from BCs and internal surface of AERs, respectively. Of the 420 rinse samples collected from the BC of the GI endoscopes, 300 were obtained from the BCs of gastroscopes and 120 from BCs of colonoscopes. Samples were collected by flushing the BCs with sterile distilled water, and swabbing the residual water from the AERs after reprocessing. These samples were cultured to detect the presence of aerobic and anaerobic bacteria and mycobacteria.

Results

The number of culture-positive samples obtained from BCs (13.6%, 57/420) was significantly higher than that obtained from AERs (1.7%, 7/420). In addition, the number of culture-positive samples obtained from the BCs of gastroscopes (10.7%, 32/300) and colonoscopes (20.8%, 25/120) were significantly higher than that obtained from AER reprocess to gastroscopes (2.0%, 6/300) and AER reprocess to colonoscopes (0.8%, 1/120).

Conclusions

Culturing rinse samples obtained from BCs provides a better indication of the effectiveness of the decontamination of GI endoscopes after HLD than culturing the swab samples obtained from the inner surfaces of AERs as the swab samples only indicate whether the AERs are free from microbial contamination or not.

Sequential cohort study comparing chlorine dioxide wipes with automated washing for decontamination of flexible nasendoscopes

Introduction:

Flexible nasoendoscope is an important tool in otorhinolaryngology practice. The endoscope needs to be decontaminated prior to use in the next patient. The 2005 ENT-UK guidance for cleaning fibre-optic laryngoscopes stated that the ideal disinfecting agent and process should be effective and have low capital and maintenance costs.

Objective:

To compare the efficacy and cost-effectiveness of chlorine dioxide wipes versus automated washer, for decontamination of flexible nasendoscopes.

Methods:

A sequential cohort,in vitrostudy was performed to test the efficacy of chlorine dioxide wipes and automated washer. Costs were also calculated.

Results:

After deliberate bacterial contamination of the nasendoscope and subsequent decontamination, swab samples from the endoscope showedStaphylococcus epidermidisgrowth in 2 per cent (1/50 swabs) of the chlorine dioxide wipe group and in 28 per cent (14/50 swabs) of the automated washer group (p = 0.00). Based on a projected 10-year cost calculation, the automated washer was cheaper.

Conclusion:

Further studies are required to test whether these results are replicable. A similar study should be performed using real patients, to check the significance of improper decontamination.

Reuse of medical devices: implications for infection control

Reuse of both single-use and multiuse medical devices is a common practice and can result in transmission of infection when appropriate sterilization or reprocessing does not occur. Reuse of single-use devices can be problematic because there are no clear standards for reprocessing, although data regarding adverse outcomes are limited. Single-use devices are commonly reused, appropriately or inappropriately, in resource-limited settings because of cost constraints. Reuse of medical devices raises important legal and ethical questions.

Comparison of sterilization of reusable endoscopic biopsy forceps by autoclaving and ethylene oxide gas

BACKGROUND AND AIMS

Every country has standardized reprocessing guidelines for reducing the risk of microorganism transmission via reusable biopsy forceps. Sterilization is performed either by autoclaving or with the use of ethylene oxide (EO) gas. However, there are no clear standard global recommendations. The aim of this study was to determine whether EO gas or autoclaving is a safer and more effective method for the sterilization of reusable forceps.

METHODS

This was a prospective study conducted at multiple tertiary referral centers. Seventy reusable biopsy forceps that had been reused at least 20 times each were collected from six endoscopy centers. In all, 61 forceps from five centers were sterilized using EO gas, and the nine forceps from the remaining center were placed in an autoclave. We performed real-time polymerase chain reaction (RT-PCR) for Mycobacterium tuberculosis and hepatitis B virus and performed bacterial cultures on the reusable forceps, which were cut into 2- to 3-cm sections. The forceps were also scanned with an electron microscope (EM) to detect surface damage and contamination.

RESULTS

Escherichia coli bacteria were cultured from 2 of the 61 (3.3%) reusable biopsy forceps sterilized with EO gas. On EM scanning, abundant debris and tissue materials remained on the cup surfaces of the reused biopsy forceps and on their inner wires. No microorganisms were found on the autoclaved forceps.

CONCLUSIONS

Sterilization with EO gas may be inadequate because the complicated structure of the forceps may interfere with sterilization. Therefore, for optimum safety, reusable biopsy forceps should be sterilized by autoclaving.

Assessment on experimental bacterial biofilms and in clinical practice of the efficacy of sampling solutions for microbiological testing of endoscopes

Opinions differ on the value of microbiological testing of endoscopes, which varies according to the technique used. We compared the efficacy on bacterial biofilms of sampling solutions used for the surveillance of the contamination of endoscope channels. To compare efficacy, we used an experimental model of a 48-h Pseudomonas biofilm grown on endoscope internal tubing. Sampling of this experimental biofilm was performed with a Tween 80-lecithin-based solution, saline, and sterile water. We also performed a randomized prospective study during routine clinical practice in our hospital sampling randomly with two different solutions the endoscopes after reprocessing. Biofilm recovery expressed as a logarithmic ratio of bacteria recovered on bacteria initially present in biofilm was significantly more effective with the Tween 80-lecithin-based solution than with saline solution (P = 0.002) and sterile water (P = 0.002). There was no significant difference between saline and sterile water. In the randomized clinical study, the rates of endoscopes that were contaminated with the Tween 80-lecithin-based sampling solution and the saline were 8/25 and 1/25, respectively (P = 0.02), and the mean numbers of bacteria recovered were 281 and 19 CFU/100 ml (P = 0.001), respectively. In conclusion, the efficiency and therefore the value of the monitoring of endoscope reprocessing by microbiological cultures is dependent on the sampling solutions used. A sampling solution with a tensioactive action is more efficient than saline in detecting biofilm contamination of endoscopes.

Lumen claims of the STERRAD 100NX sterilizer: testing performance limits when processing equipment containing long, narrow lumens

BACKGROUND

According to manufacturers information, the STERRAD 100NX sterilizer-a low temperature H(2)O(2) gas plasma sterilizer-can adequately process single channel stainless steel lumens with an inside diameter of 0.7 mm or larger and a maximum length of 500 mm using standard cycle sterilizing conditions. The aim of this study was to qualify the performance of this H(2)O(2) gas plasma sterilizer under different experimental settings representing worst case conditions.

METHODS

Inoculated carriers were placed at the midpoint position of specified lumens and then submitted to flex scope sterilizing conditions. To simulate insufficient cleaning or crystalline residues, we added organic and inorganic challenges to our inoculated carriers.

RESULTS

For experiments done with unchallenged carriers, quantitative analysis reached a log(10) reduction rate of ≥5.71, whereas qualitative results showed no growth in 24 out of 30 biologic indicators tested using flex scope half cycle conditions. Any additional kind of challenge significantly impaired the sterilization outcome.

CONCLUSION

The findings of our current study emphasize the importance of a thorough validated cleaning of medical devices as well as timing for cleaning and decontamination before being exposed to the H(2)O(2) sterilization process and, furthermore, the need for strict adherence to manufacturer's recommendations.

Endoscope reprocessing using glutaraldehyde in endoscopy services of Goiânia, Brazil: a realidade em serviços de endoscopia de Goiânia, GO

CONTEXT

The endoscopic procedure safety depends on the use of an adequately reprocessed device which quality is related to each of its operational steps.

OBJECTIVE

To characterize the reprocessing of endoscopes using glutaraldehyde in endoscopy services

METHODS

Study was conducted by observing the reprocessing of 60 endoscopes from 20 medical practices of the municipality of Goiânia, GO, central area of Brazil.

RESULTS

This study showed failure in all reprocessing steps. The pre-washing was performed in 24 (40.0%) of the endoscope. In the cleaning steps, was identify the improper use of enzymatic detergent, and in 27 (45.0%) cases, the brushing of internal channels was not performed. All 60 endoscopes were submitted to this disinfectant. However, for 33 (55.0%) of the cases the internal channels was not filled. The total immersion of endoscope in the glutaraldehyde was not performed in 39 (65.0%) cases. The recommended minimum total immersion time for exposure to 2% glutaraldehyde solution was followed only for 12 (20.0%) endoscopes. There was no filter for water treatment used in the rinse of most endoscopes 54 (90.0%) and to dry the internal channels only 6 (10.0%) of them used compressed air. Adequate storing conditions were identified.

CONCLUSION

Considering the particularities of the endoscope and its reprocessing, it is imperative to establish protocols to ensure the quality of the disinfection and the prevention of cross-contamination.

Quality assurance in endoscopy nursing

Since the 1960s quality assurance has become an integral part of medicine and nursing. The aims of quality assurance cover patient and staff safety and satisfaction, economical factors and the implementation of health care policy. Endoscopy units can be established in hospitals, primary care or ambulatory endoscopy centres. The quality of endoscopy facilities should be the same irrespective where endoscopy is carried out. Endoscopy staff is responsible for individualised, comprehensive patient care, technical assistance including reprocessing, documentation and management of endoscopy units. Quality criteria for endoscopy nursing cover pre, intra and post procedure care. However, a complete separation between clinical medical and nursing outcome criteria is often difficult in Endoscopy, as the clinical interventions are a combination of both medical and nursing actions. It is the combined effort of all staff with the support from the health care provider that leads to a high quality of patient care in Endoscopy.

Infection Control in the Sonography Department

Knowledge of how to prevent healthcare-associated infections within the sonography department is an important step in providing quality care. Employing scientifically based preventative measures will ensure that the tools we use do not become vectors for the spread of pathogens that cause infections. These avoidable infections have not only an added financial cost to patients and the already burdened healthcare system but also physical and emotional costs to the patients we treat. Specific infection control guidelines for the sonography department are lacking, and the guidelines that are available are often based on proven infection control practiced in similar situations. Within this article are the applicable infection guidelines sonographers can use to provide safe quality care.

Aldahol high-level disinfectant

BACKGROUND

Glutaraldehyde and ortho-phthalaldehyde (OPA) are widely used as the active ingredients of high level disinfectants for heat-sensitive, semicritical medical instruments. However, both of these chemicals have limitations in their spectrum of antimicrobial activity. Glutaraldehyde disinfectants are poorly mycobactericidal, and require impractically long exposure times to kill spore-forming bacteria. OPA disinfectants kill many types of mycobacteria in practical exposure times, but require 32 hours to pass the Association of Official Analytical Chemists (AOAC) sporicidal test, and do not claim to be sterilants. These could be serious limitations that contribute to the formation of biofilms in endoscopes, after which the endoscopes are difficult to disinfect. The objective of our research was to discover a disinfectant formulation, based on aldehydes, that killed mycobacteria and spore-forming bacteria in a practical exposure time and temperature.

METHODS

Solutions of glutaraldehyde or OPA were prepared with various concentrations of alcohols, sodium and potassium salts, chelating agents, and detergents at alkaline pH values, and tested against cultures of mycobacteria and spore-forming bacteria to find a formulation that would kill these bacteria in practical exposure times at 20 degrees C or 25 degrees C.

RESULTS

Concentrations of < or =20% w/w isopropanol and < or =8% potassium acetate in combination with < or =3.5% w/w glutaraldehyde at alkaline pH values killed 6 log(10) of mycobacteria within 10 minutes at 20 degrees C. Similar combinations killed 6 log(10) of Bacillus subtilis in suspension within 30 minutes at 25 degrees C, and B subtilis within 60 minutes at 20 degrees C. The sporicidal activity of OPA was not increased by combination with isopropanol and potassium acetate salts.

CONCLUSIONS

Aldahol high-level disinfectant (US FDA K041360), a formulation of 3.5% glutaraldehyde in combination with 20% w/w isopropanol and 8% potassium acetate, kills mycobacteria within 10 minutes at 20 degrees C and kills 6 log(10) of cultures of the spore-forming bacteria B subtilis within 60 minutes at 20 degrees C.

US outbreak investigations highlight the need for safe injection practices and basic infection control

Current understanding of viral hepatitis transmission in United States health care settings indicates progress over the past several decades with respect to the risks from transfusions or blood products. Likewise, risks to health care providers from sharps injuries and other blood and body fluid exposures have been reduced as a consequence of widespread hepatitis B vaccination and the adoption of safer work practices. Increasing recognition of outbreaks involving patient-to-patient spread of hepatitis B and hepatitis C virus infections, however, has uncovered a disturbing trend. This article highlights the importance of basic infection control and the need for increased awareness of safe injection practices.

An outbreak of Pseudomonas aeruginosa infections following thoracic surgeries occurring via the contamination of bronchoscopes and an automatic endoscope reprocessor

An outbreak of Pseudomonas aeruginosa infections occurred after thoracic surgeries performed between May and June 2003. Clinical data of seven patients were reviewed and the fact was revealed that bronchoscopes were used during endotracheal intubation for one-lung ventilation in most patients. P. aeruginosa was recovered from the sputum of these patients at a very early stage post-operation. Environmental samples from bronchoscopes and an automated endoscope reprocessor (AER) were cultured and P. aeruginosa strains were recovered from all of them. All of these strains were confirmed to be identical by pulsed-field gel electrophoresis (PFGE). Inspection of the sterilization cycles of bronchoscopes revealed inappropriate management of bronchoscopes and a flaw in the AER; once its detergent tank was contaminated, it was not possible to disinfect it. After all the bronchoscopes had been disinfected, and the washing machine had been remodeled, with the washing process confirmed to be appropriate, the outbreak finally ended. This outbreak had two causes, a flaw in the AER and inappropriate disinfection procedures. Outbreaks associated with bronchoscopic examinations have been reported elsewhere. Bronchoscopes are widely used to facilitate endotracheal intubation, especially for one-lung anesthesia. Although they are used for only a short time during anesthetic procedures, we should handle them more carefully.

Resistance and cross-resistance to oxidising agents of bacterial isolates from endoscope washer disinfectors

Bacteria isolated from washer disinfectors using chlorine dioxide as a high-level disinfectant were exposed to peracetic acid, chlorine dioxide and hydrogen peroxide to investigate their susceptibility and possible bacterial cross-resistance to these highly reactive oxidising biocides. A standard suspension test was used to establish a rate of kill of these biocides against two stable isolates (Bacillus subtilis and Micrococcus luteus). Suspension tests demonstrated that 'in use' concentrations were not always effective to provide the required disinfection efficacy within recommended exposure times and in some instances a 60min exposure was necessary to achieve a reduction in number by a factor of 10(5). It appears that vegetative Gram-positive isolates can become resistant to oxidising agents in vitro, and that cross-resistance to related compounds can occur. Since these bacteria are deemed to be susceptible to highly reactive biocides, there should be further study of the resistance mechanisms in these isolates to explain their survival.

Microbiological monitoring of endoscopes: 5-year review

Periodic microbiological monitoring of endoscopes is a recommendation of the Gastroenterological Society of Australia (GENSA). The aim of monitoring has been to provide quality assurance of the cleaning and disinfection of endoscopes; however, there is controversy regarding its frequency. This lack of consensus stimulated a review of the experience within our health service. At Southern Health, routine microbiological sampling has involved 4-weekly monitoring of bronchoscopes, duodenoscopes and automated flexible endoscope reprocessors (AFER), and 3-monthly monitoring of all other gastrointestinal endoscopes. Records of testing were reviewed from 1 January 2002 until 31 December 2006. A literature review was conducted, cost analysis performed and positive cultures investigated. There were 2374 screening tests performed during the 5-year period, including 287 AFER, 631 bronchoscopes for mycobacteria and 1456 endoscope bacterial screens. There were no positive results of the AFER or bronchoscopes for mycobacteria. Of the 1456 endoscopic bacterial samples, six were positive; however, retesting resulted in no growth. The overall cost of tests performed and cost in time for nursing staff to collect the samples was estimated at $AUD 100,400. Periodic monitoring of endoscopes is both time-consuming and costly. Our review demonstrates that AFER (Soluscope) perform well in cleaning endoscopes. Based on our 5-year experience, assurance of quality for endoscopic use could be achieved through process control as opposed to product control. Maintenance of endoscopes and AFER should be in accordance with the manufacturer's instructions and microbiological testing performed on commissioning, annually and following repair. Initial prompt manual leak testing and manual cleaning followed by mechanical leak testing, cleaning and disinfection should be the minimum standard in reprocessing of endoscopes.

[Five years of the Robert Koch Institute guidelines for reprocessing of flexible endoscopes. A look back and a look forward]

In a short review the national and international reception of the German guidelines for reprocessing flexible endoscopes is presented. The recommendations of the guidelines are discussed in view of recent knowledge on old problems such as prion inactivation and new infectious diseases and new microorganisms such as SARS, avian influenza and C. difficile. New disinfectants and new methods for endoscope disinfection are mentioned, the importance of careful cleaning is underlined. The German guidelines of the Robert Koch Institute and the US Multi-Society guidelines, published in 2003, are compared. The discrepancies concerning recommendations for water quality for final rinsing and need of microbiological controls of endoscope reprocessing are stressed. Aspects not mentioned in the German guidelines, e.g. duration of storage after reprocessing and risk of infection transmission by the endo-washer, are discussed.