Publications

Résumé : Malgré les nombreux efforts réalisés dans le domaine des procédures de traitement des endoscopes, le risque infectieux associé à l’utilisation d’endoscopes reste d’actualité. Le prélèvement microbiologique des canaux internes des endoscopes reste un outil de référence pour l’évaluation de la qualité microbiologique des endoscopes ou en tant qu’indicateur de la qualité des procédures de traitement des endoscopes. Néanmoins, pour être pleinement efficaces, ils doivent être réalisés et analysés selon une méthodologie rigoureuse et les résultats doivent être interprétés selon des critères d’interprétation clairement définis.

Résumé : The need for manual brushing of endoscope channels before cleaning and disinfecting them in automatic endoscope reprocessors (AER s) is more than ever debated. Most European national guidelines recommend or require manual brushing, while the U.S. Food and Drug Administration (FDA) and the Australian Therapeutic Goods Administration have already accepted claims of high-level disinfection by some AER s without the need for manual brushing when bedside pretreatment is performed.
This study quantitatively assayed total protein, total organic carbon, and viable aerobic bacteria remaining in endoscopes after routine clinical use in order (1) to assess cleanliness after four stages of the usual reprocessing procedure involving AER s and (2) to evaluate the validity of the benchmarks of cleanliness used to validate automatic cleaning claims. At four different hospitals in France, a total of 206 samples were taken from endoscopes – 87 from colonoscopes, 93 from gastroscopes and duodenoscopes, and 26 from bronchoscopes. 30 were collected after bedside pre cleaning; 34 after bedside pre-cleaning and channel brushing; 111 after bedside pre-cleaning, channel brushing, and automated washing (after double washing and rinses in the AER ); and 31 after bedside pre-cleaning, channel brushing, and the complete washing and disinfection cycle in the AER (full reprocessing).
Comparison of samples taken after channel brushing with samples taken before brushing indicated that brushing was important, although not necessarily indispensible, for reducing contamination remaining in endoscopes after bedside precleaning.
After the automatic wash phase, residual total organic carbon and bacterial loads were consistent with the limits proposed by Alfa et al. in 2010 and validated by the FDA for an automatic cleaning claim (i. e., < 6.4 μg/cm2 for residual protein and < 4 log10 viable bacteria/cm2) in 91 % and 99 % of cases, respectively. From the 31 endoscopes that were completely reprocessed before sampling, all bacterial counts reached the limits established for automatic cleaning claims. Mean total organic carbon after the complete cycle was onethird the value after the automatic cleaning stage (0.9 μg/cm2 after cleaning and disinfection vs. 2.8 μg/cm2 after only cleaning; not statistically significant). After full processing 23 % of total organic carbon values were lower than the detection limit of the method, in contrast to 67 % for total protein.
Thus, total organic carbon appears to be a more sensitive and reliable measure than total protein measured by Micro BCA ™ to accurately measure cleanliness levels. This study demonstrate also that the limits proposed by M. Alfa and validated by FDA and Australia (i. e., < 6.4 μg /cm2 for residual protein and < 4 log10 viable bacteria/ cm2) remain valid references for evaluation of reprocessing procedures without manual brushing.

Résumé : Background: In most countries, endoscopes must be disinfected or fully reprocessed before the beginning of each session, even if they were cleaned and disinfected after their last use. Several storage cabinets for heat-sensitive endoscopes (SCHE) are commercially available. They are designed to maintain the microbiological quality of reprocessed endoscopes for a predefined period of time validated by the SCHE manufacturer. Use of an SCHE increases the acceptable storage time before it is necessary to re-disinfect the endoscope.
Aim: To evaluate the efficacy of an SCHE (DSC8000, Soluscope, SAS Marseilles, France) in a clinical setting.
Method: The microbiological quality of endoscopes was assessed after 72 h of storage in an SCHE (Group I), and compared with the microbiological quality of endoscopes stored for 72 h in a clean, dry, dedicated cupboard without morning disinfection (Group II) and the microbiological quality of endoscopes stored for 72 h in a clean, dry, dedicated cupboard with morning disinfection (Group III). Forty-one endoscopes in each group were sampled for microbiological quality. Endoscope contamination levels were analysed according to guidelines published by the National Technical Committee on Nosocomial Infection in 2007.
Findings/conclusion: Use of an SCHE helps to maintain the microbiological quality of endoscopes, provided that staff members are well trained and all practices are framed by a proven quality assurance process.

Résumé : There is a growing interest for automated area decontamination (AAD), as an alternative or complement to manual surface disinfection procedures. However, unlike for liquid disinfection or sterilisation, consensus on efficacy evaluation benchmarks and dedicated international standard are missing for AAD. Attempts are currently made to fill those gaps. Standards for liquid disinfectants will serve as a basis, but it remains to be determined to which extent these norms formulate an appropriate basis for AAD. The objective of this article is not to discuss the content for a future AAD standard but rather to provide a brief overview of items which might deserve a debate before defining the details of an appropriate evaluation framework. Preliminary observations by confocal microscopy on Candida albicans inoculi prepared according to usual suspension standards are provided as an example of experiments which should be driven to help define that framework.

Résumé : Bien que les procédures d’entretien des endoscopes non autoclavables soient aujourd’hui parfaitement définies et adaptées, force est de constater la réalité du risque infectieux lié à l’échec de la mise en œuvre de cet entretien. Afin d’améliorer la prise en charge de la désinfection des endoscopes non autoclavables et devant les nombreuses similitudes existant entre le processus de stérilisation des dispositifs médicaux et celui de désinfection des endoscopes non autoclavables, il nous est apparu intéressant de transposer à cette activité le système de management de la qualité de la stérilisation des dispositifs médicaux réutilisables. Si depuis une dizaine d’années, ce concept apparaît par bribes dans différents référentiels, il n’est pas à l’évidence aussi avancé sur le terrain qu’en stérilisation ou dans le domaine médicamenteux.

Abstract : Cleaning efficacy was studied in a standard test method to investigate the variability of various test soils. Seven test soils were chosen both from the technical specification EN ISO/TS 15883-5 (1) and from what have been described in the literature. Each soil was tested on exposure to three different standard solutions, such as distilled water, a detergent (SDS) solution and an alkali (NaOH) dilution, over three exposure times. Soiling and recovery methods were validated as part of the investigation. Cleaning efficacy was evaluated by protein quantification. The test soils varied considerably in efficacy ranging from complete to little or no removal. The results demonstrate the need for the development and acceptance of standardized test soils that can be reproducible and predictable of cleaning efficacy.

Abstract : Following a French circular published in 2001, the use of glutaraldehyde for the disinfection of reusable medical devices was abandoned in favour of non-fixative disinfectants such as peracetic-acid-based solutions. Data published regarding the fixative properties of alternative disinfectants remain contradictory. We compared the effect of repetitive treatments of polytetrafluoroethylene (PTFE) tubes, contaminated by a liquid medium inoculated with Pseudomonas aeruginosa, using five different disinfectant solutions: two peracetic acid solutions (with and without an activator), glutaraldehyde, ortho-phthaldehyde and succine dialdehyde. The results confirmed that repeated treatments of a PTFE tube with a 2% glutaraldehyde solution induce an important accumulation and/or fixation of protein, compared to peracetic-acid-based disinfectants, for which the accumulation and/or fixation of proteins remain low and vary from one formulation to another.

Abstract : The resistance of bacterial biofilms to physical and chemical agents is attributed in the literature to various interconnected processes. The limitation of mass transfer alters the growth rate, and physiological changes in the bacteria in the film also appear. The present work describes an approach to determination of the mechanisms involved in the resistance of bacteria to quaternary ammonium compounds (benzalkonium chloride) according to the C-chain lengths of those compounds. For Pseudomonas aeruginosa CIP A 22, the level of resistance of the bacteria in the biofilm relative to that of planktonic bacteria increased with the C-chain length. For cells within the biofilm, the exopolysaccharide induced a characteristic increase in surface hydrophilicity. However, this hydrophilicity was eliminated by simple resuspension and washing. The sensitivity to quaternary ammonium compounds was restored to over 90%. Staphylococcus aureus CIP 53 154 had a very high level of resistance when it was in the biofilm form. A characteristic of bacteria from the biofilm was a reduction in the percent hydrophobicity, but the essential point is that this hydrophobicity was retained after the biofilm bacteria were resuspended and washed. The recovery of sensitivity was thus only partial. These results indicate that the factors involved in biofilm resistance to quaternary ammonium compounds vary according to the bacterial modifications induced by the formation of a biofilm. In the case of P. aeruginosa, we have underlined the involvement of the exopolysaccharide and particularly the three-dimensional structure (water channels). In the case of S. aureus, the role of the three-dimensional structure is limited and drastic physiological changes in the biofilm cells are more highly implicated in resistance.

Abstract : Inadequate drying of endoscope channels is a possible cause of microbial proliferation during storage. This risk could be reduced by any procedure or process used to dry endoscope channels and control storage conditions. The efficacy of a drying and storage cabinet (Hysis Medical) was tested on three different endoscopes: a colonoscope (Olympus); duodenoscope (Fujinon) and an enteroscope (Pentax), all of which had been artificially contaminated with a suspension of Pseudomonas aeruginosa CIP 103467. Changes to the residual internal contamination level of these endoscopes when stored inside or outside the drying cabinet for 12, 24, 48 or 72 h were compared. When stored in the drying and storage cabinet, microbial contamination levels on endoscopes were lower than the number of bacteria initially introduced and could decrease considerably thereafter. For endoscopes stored outside the drying storage cabinet, microbial numbers were stable or even increased. These data demonstrate the advantages of such endoscope drying/storage cabinets that limit the risk of bacterial proliferation in the internal channels of endoscopes during storage, and which ensure that the disinfection level reached at the end of the reprocessing procedure is maintained.

Abstract : The tests presented in this study were carried out to evaluate the cleaning and biocidal efficacies of a steam cleaning-disinfection procedure (Sanivap method) according to three experimental protocols. The first study evaluated the cleaning efficacy of the Sanivap procedure against surfaces artificially contaminated with a com- plex test soil. The second test series consisted in evalu- ating biocidal efficacy of the Sanivap method according to a standardized carrier test. The third one allowed to evaluate this procedure against bacterial biofilms formed on inert support. The results obtained demonstrate that the SANIVAP method presents a good cleaning efficacy against the complex test soil and the bacterial biofilm coupled to an efficient biocidal activity against vegeta- tive bacteria, mycobacteria, yeasts and fungi as well as against bacteria present within biofilms.

Abstract : Despite the benefits of flexible endoscopes for diagnostic and therapeutic procedures, their widespread use has underlined that endoscopy carries a risk of infection. Effective cleaning and disinfection procedures are important.

.

Abstract : Despite technological evolutions and progress observed regarding reprocessing of reusable medical devices, digestive endoscopy remains a medical examination which can be at the origin of nosocomial infections. Micro-organisms and mechanisms involved in post-endoscopy infections are many and the infectious risk varies according to the transmissible agent considered and the nature of the endoscopy exam performed. However, compliance with the basic rules of hospital hygiene and the application of rigorous validated and regularly evaluated cleaning and disinfection procedures are of the utmost importance in the prevention and fight against post-endoscopy infections.

.

Résumé : Les établissements de santé rencontrent certaines difficultés pour la mise en oeuvre d’un entretien des nasofibroscopes et des fibroscopes utilisés pour les intubations difficiles conforme aux dernières recommandations en vigueur de la circulaire DHOS/E2/DGS/SD5C/ 2003 n°591 du 17 décembre 2003. La mise sur le marché français récente d’endoscopes optiques, souples, sans canal et stérilisables par la vapeur, dont un nasofibroscope, pourrait apporter une alternative intéressante. Ce matériel, innovant grâce à sa compatibilité avec la stérilisation par la vapeur, permettrait de réduire le risque de transmission d’agents transmissibles conventionnels mais également celui liés aux micro-organismes conventionnels. La prise en charge de son entretien par les services cliniques serait simplifiée. Notre étude a permis de vérifier l’efficacité d’un cycle de stérilisation par la vapeur (134°C, 18 min) sur un endoscope après perforation de la gaine ayant entraîné la contamination du matériel. Les résultats encourageants des tests effectués en laboratoire devront être complétés par des essais sur sites pour vérifier si ce matériel répond aux attentes de chacun.

Résumé : Les établissements de santé rencontrent certaines difficultés pour la mise en oeuvre d’un entretien des nasofibroscopes et des fibroscopes utilisés pour les intubations difficiles conforme aux dernières recommandations en vigueur de la circulaire DHOS/E2/DGS/SD5C/ 2003 n°591 du 17 décembre 2003. La mise sur le marché français récente d’endoscopes optiques, souples, sans canal et stérilisables par la vapeur, dont un nasofibroscope, pourrait apporter une alternative intéressante. Ce matériel, innovant grâce à sa compatibilité avec la stérilisation par la vapeur, permettrait de réduire le risque de transmission d’agents transmissibles conventionnels mais également celui liés aux micro-organismes conventionnels. La prise en charge de son entretien par les services cliniques serait simplifiée. Notre étude a permis de vérifier l’efficacité d’un cycle de stérilisation par la vapeur (134°C, 18 min) sur un endoscope après perforation de la gaine ayant entraîné la contamination du matériel. Les résultats encourageants des tests effectués en laboratoire devront être complétés par des essais sur sites pour vérifier si ce matériel répond aux attentes de chacun.

.

Abstract : Since the 1980′s endoscope washer-disinfectors have been increasingly used and a large number of automated reprocessors for flexible endoscopes are now available on the market.). Available automatic endoscope reprocessors vary in certain fundamental aspects including : the number of endoscopes reprocessed per cycle (one or two, asynchronously or simultaneously), the system used to ensure the irrigation of endoscope channels, the nature of the reprocessing (chemical or thermochemical), the reuse of chemical agents, the duration of the standard endoscope washing-disinfection cycle, etc….These machines differ also in their capacity to clean and disinfect endoscopes and some AERs are still found to be responsible for patient contamination. Most of these problems are associated with the failure to respect manufacturer’s instructions, periodic preventive maintenance measures, but also the flawed design of the washer-disinfector.

Résumé : Dans le cadre de l’évaluation des procédures d’entretien des endoscopes, les prélèvements microbiologiques des canaux constituent une intéressante méthode, utilisée ici pour évaluer en condition d’usage un couple « nettoyant enzymatique à activité bactéricide-désinfectant à base d’acide peracétique » sur quatre gastroscopes et trois coloscopes. L’étude de la contamination initiale a montré un important niveau de contamination avec présence de micro-organismes à risque nosocomial majeur (MORNM) pour deux endoscopes sur sept. Deux semaines après la mise en place de la nouvelle procédure, les prélèvements effectués à une semaine d’intervalle ont montré des résultats très satisfaisants avec moins de 50 UFC par endoscope et absence de MORNM. Malgré leur intérêt indéniable, les prélèvements microbiologiques des canaux ne se substituent ni à l’évaluation de l’application des procédures, ni aux audits de pratique mais les complètent. Par ailleurs, ils nécessitent des conditions de prélèvement et d’analyse des échantillons standardisées ainsi que la définition de niveaux microbiens seuils pour l’interprétation des résultats.

.

Abstract : Compare to manual reprocessing, endoscopes washer-disinfectors present numerous advantages with notably, the increase of microbiological safety with the standardisation of validated treatment procedures, the reduction of staff exposure to chemicals but also tracability improvement. Unfortunately some disadvantages associated to the use of such systems are always described (inefficient self-disinfection cycle, equipment unsuited to treat some endoscopes, no control of the endoscope channels irrigation, incomplete tracability, etc…).
The publication, of new French guidelines and international standards shall induces endoscope washer-disinfector manufacturers to improve their system in order to satisfy all user and regulatory requirements.

Abstract : Within the framework of thermosensitive medical devices reprocessing like endoscopes, the cleaning stage is probably the most important stage of the cleaning/disinfection process Unfortunately, at this time there is no standard nor standardized or recognized test method to make sure that products used during the cleaning phase present the required efficacy level. Considering the emergence of new variant of Creutzfeldt-Jakob disease, the evaluation of cleaning efficacy takes an additional interest first of all because of the proteinic nature of the considered infectious agent but also because disinfectants available for endoscopes are not or only partialy effective against non concentionnal transmissible agents.

Résumé : Les cas d’infections liés aux actes d’endoscopie digestive restent rares compte tenu du nombre important d’examens réalisés. Les micro-organismes les plus fréquemment isolés dans les cas de contaminations sont principalement d’origine hydrique, tel que Pseudomonas aeruginosa. Par ailleurs, ces dernières années, l’endoscopie digestive a été impliquée dans la transmission de Helicobacter pylori et du virus de l’hépatite C. Dans ce dernier cas, seule la réalisation d’une enquête épidémiologique minutieuse, prenant en compte tous les facteurs de contamination possibles, permettra de définir l’origine réelle de la contamination. En conclusion, les agents transmissibles conventionnels présentent une importante sensibilité vis-à-vis des désinfectants actuellement disponibles et le strict respect des procédures de désinfection ou de stérilisation recommandées doit permettre de maîtriser le risque infectieux lié aux dispositifs médicaux en endoscopie digestive

Abstract : The activity of 19 antibiotics and four antiseptics and/or disinfectants was studied against 138 non-redundant strains of Aeromonas spp. (104 Aeromonas caviae, 22 Aeromonas sobria and 12 Aeromonas hydrophila) isolated from two European rivers. Antibiotic resistance frequencies were: nalidixic acid, 59%; tetracycline, 14%; fosfomycin, 8%; tobramycin and cotrimoxazole, 7%; cefotaxime, 4%; chloramphenicol, 2%; gentamicin, 1%. Most of the nalidixic acid-resistant strains were susceptible to fluoroquinolones (54-98%). Antibiotic resistance rates varied according to the source of the strains. All Aeromonas spp. strains were killed by 50 ppm of chlorine, cetylpyridinium chloride and peracetic acid, and by 1600 ppm of glutaraldehyde.

.

.

Many automatic washer disinfectors for flexible endoscopes have been marketed and offered as an alternative method of preventing infections, but they are frequently unsatisfactory. There is therefore clearly a need to test prototypes prior to marketing, following an evaluation process that is sufficiently reliable and rigorous to guarantee the efficacy of the decontamination processes.

The present study describes an experimental method based on the follow-up of the decontamination of a Tygon tube, the internal surface of which was contaminated by a bacterial biofilm. This method is proposed as a preliminary test for evaluating washer disinfectors.

An analysis of the results obtained after technical modifications of the first prototype of the Fibro-Cleaner showed that complementary activities of each successive cycle phase allow a reduction in the number of adherent bacteria of more than 8 log per cm2 of support. With the three different biofilms tested (Escherichia coli, Pseudomonas aeruginosa mucoid and Staphylococcus aureus), no microorganisms were recovered from the support at the end of the decontamination process.

The experimental protocol suggested here seems to be well suited for assessing washer disinfectors during the development phase of the prototype, as well as for comparative studies.

L’évaluation de l’efficacité d’une procédure de nettoyage et de désinfection des endoscopes doit être basée sur des tests bactériologiques suffisamment rigoureux et fiables pour éviter tout risque de surévaluation et par conséquent de contamination ultérieure des endoscopes ou de la machine.Tout protocole d’évaluation doit donc impérativement tenir compte des capacités d’adhésion des micro-organismes aux différentes surfaces qui peuvent leur conférer une résistance importante aux désinfectants et/ou aux procédés de nettoyage.Le protocole expérimental présenté dans la première partie de cette étude est basé sur le suivi de la décroissance d’une population bactérienne adhérée au sein d’un biofilm formé sur tube Tygon . Cette méthode d’évaluation standardisée pourrait constituer un pré-requis intervenant en amont des tests réalisés par l’utilisateur. Ces tests permettraient alors, comme cela est décrit dans la deuxième partie de cette étude, de quantifier précisément et d’optimiser le pouvoir détersif et désinfectant des machines à laver et désinfecter les endoscopes.