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Impact of the amount of hand rub applied in hygienic hand disinfection on the reduction of microbial counts on hands.
P. Goroncy-Bermes, T. Koburger, B. Meyer

Two different hand rubs were tested in order to investigate the minimum volume required for microbicidal efficacy according to the European Norm EN 1500; we also sought to determine whether there is a correlation with hand size. Eight male volunteers with big hands (mean 184 cm(2)) and eight female volunteers with significantly smaller hands (mean 148 cm(2); P<0.001) participated in our study. Application of 2 mL of both products (P) provided mean log(10) reductions significantly smaller than those of the reference disinfectant (R) (product A: P=3.34, R=4.00, P=0.001; product B: P=3.37, R=3.75, P=0.022). Higher volumes (product A: 3 and 4 mL; product B: 2.5, 3 and 4 mL) ensured that the pass criteria of the European Norm (EN) 1500 were fulfilled. For both products log(10) reductions increased with increasing product volume until a plateau was reached. For the smaller female hands, this plateau level was reached after applying 3 mL of product A and 2.5 mL of product B. The plateau level on male hands was observed after treating the hands with > or =4 mL of product A and 3 mL of product B. The increase in product volume also correlated with the decrease in the number of volunteers considering the product volume applied as insufficient. In conclusion, the applied volume for hygienic hand rub should not fall below 3 mL in order to achieve maximum benefit.

Copyright 2009 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.

Comparison of two test methods for the determination of sufficient antimicrobial activity of three commonly used alcohol-based hand rubs for hygienic hand disinfection.
P. Goroncy-Bermes, G. Kampf, B. Meyer

In Europe, the antimicrobial efficacy of alcohol-based hand rubs is determined with a quantitative suspension test (prEN 12054) and a test under practical conditions (EN 1500). Another test method has recently been published by the German Society for Hygiene and Microbiology (DGHM) with four differences to the European system in the in vitro tests: additional qualitative suspension tests with product dilutions to the ineffective range; a selection of the most resistant Gram-negative test strains in the qualitative suspension test, which should be used adjacent to Pseudomonas aeruginosa in the quantitative suspension test; a high organic load in the quantitative suspension tests (0.3% albumin and 0.3% sheep erythrocytes); and an aqueous control in the quantitative suspension test. According to DGHM, the in vitro tests should be followed by EN 1500. We have determined the antimicrobial efficacy of three commonly used alcohol-based hand rubs according to both methods. prEN 12054 was carried out without organic load. The qualitative suspension tests (DGHM) were carried out with P. aeruginosa, Escherichia coli, Proteus mirabilis, Staphylococcus aureus, Enterococcus hirae and Candida albicans. The quantitative suspension test (DGHM) was carried out with product dilutions of 75%, 50% and 25%, and a high organic load using the following test organisms: P. aeruginosa, P. mirabilis (one product only), S. aureus, E. hirae and C. albicans. All these suspension tests were carried out in quadruplicate with each product and exposure time. EN 1500 was carried out with 3 mL of each product and an application time of 30 s. All three products achieved the required bactericidal activity of prEN 12054 and the new DGHM method within 30 s, and were equally effective with the reference hand disinfection of EN 1500 within 30 s. In our study, the DGHM test method did not provide additional information for hand rubs which exhibit their bactericidal efficacy with 3 mL within 30 s (EN 1500).

Rubs vs. Scrubs - Study of compatibility of hand disinfectants
Sabine Behrends, Andrea Rodewald

It is an inevitable part of the work of medical personnel that they are presenting a high risk in terms of transferring microorganisms from one patient to another.

Direct contact between staff and patients cannot be avoided in everyday routine, and the surface structure of the skin provides plenty of adherence opportunities for organisms.

Global Studies
These factors are demonstrated by a number of studies across the world, which indicate that around 5-12% of hospital patients contract an infection - with more that a half of these being avoidable. The incidents with intensive care units are even higher - up to 25%.

So what can be done to help suppress the opportunities for cross-contamination? It makes sense that high levels of hygiene need to be maintained at all times - but ensuring the optimum products and facilities are provided will be a case of ensuring that staff's own needs are met.

Hand disinfecting Methode
We undertook our own research to look at the various factors relating to the preferred method of hand washing by medical staff - with an objective of comparing the skin - compatibility of conventional hand washing with antiseptic soap versus a new alcohol-based hand rub.

A total of 19 volunteers aged between 20 and 65 and with healthy skin participated in the survey. Of these, three were male and 16 female and they took part for three weeks on workdays only, using the test preparations five to seven times a day.

The preparations available for hand disinfecting can be divided into two groups - alcoholic rubs (Product A) and disinfectant hand washes -scrubs- (Product B)

Multicentre Trial on Standardisation of a Test Soil of Practical Relevance for Comparative and Quantitative Evaluation of Cleaning Pursuant to EN ISO 15883 – Description of Test Procedure
J. Köhnlein, R. Glasmacher, V. Heide, D. Kunde, M. Mohr, D. Otto, M. Pieper, K. Roth, J. Staffeldt, P. Tiarks, S. Wagenknecht, H.-P. Werner, W. Michels

The ad hoc group ”Test soils and methods“, part of the standards committee NA Med 063-04-09 of the DIN, had reported in a previous edition of this journal initial results of a multicentre trial with an ”in vitro reference system“ for the comparative evaluation of test soils for testing the cleaning performance of washer-disinfector appliances (WD) according to EN ISO 15883-1 and ISO/TS 15883-5. Exploratory information about materials and methods was given there. This contribution now gives detailed information on the execution of the tests.

Medical Device Reprocessing as Reflected 17 Years after Introduction of the Medical Devices Act
Evaluation of the DGSV congress workshop devoted to this topic
F. Bakker, M. Schreiner, F. Böhlke

It is not just the coming into force of the Medical Devices Act (MPG), based on European Directive 93/42/EEC of 14 June 1993, that has been the chief driver of the ongoing improvements seen in the quality of medical device reprocessing and in the tightening of the requirements addressed to the users. In addition to a plethora of recommendations, guidelines and legal acts, new technologies, modern materials, devices and processes accentuate the
need for commensurately skilled users and for conductance of reprocessing in line with the state of the art in science and technology. Workshop 3 held at the German Society of Sterile Supply (DGSV) conference 2010 in Fulda, ”Medical device reprocessing as reflected 17 years after introduction of the Medical Devices Act“, focused on various stages of the instrument
circuit, with delegates expressing their views through an anonymous polling system. Simultaneous presentation and evaluation of the responses granted delegates insights into the extent to which MPG has been implemented 17 years after its introduction, while highlighting
also where there is still need for action and for further discussion. The workshop was directed in particular towards those responsible for, or working in the field of, medical device reprocessing, e. g. Central Sterile Supply Department (CSSD) or endoscopy department. This paper presents the findings of the workshop.

Introduction
Within the framework of four workshops held during the DGSV annual conference from 7 to 9 October 2010 in Fulda a total of 80 participants were surveyed for their views on medical device reprocessing and on implementation of the Medical Devices Act (MPG) within their establishment. The survey was conducted using a TED system, thus permitting anonymous evaluation of the responses. The main aim was to ascertain to what extent MPG has been implemented 17 years after its introduction. As illustrated in Figure 1, respondents consisted of a large variety of representatives of larger and smaller CSSDs.

Results
The question regarding the highest qualification in the respondent’s own CSSD showed that almost two-thirds of respondents stated that at least one person in the CSSD had successfully completed Specialist Training Course III (a training course designed for CSSD personnel). One out of every seven respondents even stated that their CSSD employed a staff member with a qualification higher than that of Specialist Training Course III. Only one respondent said that the CSSD had no qualified person.
The question as to whether a quality management system was in place in the
respondent’s own CSSD was answered with ”Yes“ by over 90 % of those surveyed. However, only in around one-third of CSSDs was the QM system certified. Although more than 90 % of respondents admitted to working in a CSSD with a quality management system, in around one out of every six CSSDs medical devices were not at all classified as per the

Octenidine Dihydrochloride, a Modern Antiseptic for Skin, Mucous Membranes and Wounds
Hübner N.-O.a · Siebert J.b · Kramer A.a

A Institute of Hygiene and Environmental Medicine, Ernst Moritz Arndt University Greifswald, Greifswald, and bSchülke & Mayr GmbH, Norderstedt, Germany Skin Pharmacol Physiol 2010;23:244–258 (DOI:10.1159/000314699)

Abstract

Octenidine dihydrochloride (octenidine) was introduced for skin, mucous membrane and wound antisepsis more than 20 years ago. Until now, a wealth of knowledge has been gained, including in vitro and animal studies on efficacy, tolerance, safety and clinical experience both from case reports and prospective controlled trials. Nowadays, octenidine is an established antiseptic in a large field of applications and represents an alternative to older substances such as chlorhexidine, polyvidone-iodine or triclosan. The review is based on the current literature and unpublished original data as well.

Standardized comparison of antiseptic efficacy of triclosan, PVP–iodine, octenidine dihydrochloride, polyhexanide and chlorhexidine digluconate
T. Koburger, N.-O. Hübner, M. Braun, J. Siebert and A. Kramer

Abstract

Background: This study presents a comparative investigation of the antimicrobial efficacy of the antiseptics PVP–iodine, triclosan, chlorhexidine, octenidine and polyhexanide used for pre-surgical antisepsis and antiseptic treatment of skin, wounds and mucous membranes based on internationally accepted standards.

Methods: MICs and MBCs were determined in accordance with DIN 58940-7 and 58940-8 using Staphylococcus aureus (including methicillin-resistant Staphylococcus aureus), Enterococcus faecalis (including vancomycin-resistant Enterococcus), Streptococcus pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Clostridium perfringens, Haemophilus influenzae and Candida albicans. The microbicidal efficacy was determined in accordance with DIN EN 1040 and 1275 using S. aureus, P. aeruginosa and C. albicans.

Results: For chlorhexidine, octenidine and polyhexanide, MIC48 and MBC24 ranged from 16 to 32 mg/L. Maximum values for triclosan ranged from 256 to 512 mg/L, with an efficacy gap against P. aeruginosa, while the maximum values of PVP–iodine were 1024 mg/L, with a gap against S. pneumoniae. Comparing the minimal effective concentrations, octenidine was most effective. After 1 min, only octenidine and PVP–iodine fulfil the requirements for antiseptics.

Conclusions: Tests under standardized and harmonized conditions help to choose the most efficacious agent. When a prolonged contact time is feasible, ranking of agents would be polyhexanide = octenidine > chlorhexidine > triclosan > PVP–iodine. This is consistent with the recommendations for antisepsis of acute wounds. Polyhexanide seems to be preferable for chronic wounds due to its higher tolerability. If an immediate effect is required, ranking would be octenidine =  PVP–iodine≫ polyhexanide > chlorhexidine > triclosan.

The effect of a combination of 0.1% octenidine dihydrochloride and 2% 2-phenoxyethanol (octenisept^®) on wound healing in pigs in vivo and its in vitro percutaneous permeation through intact and barrier disrupted porcine skin
Jessica Stahl, Michael Braun,Joerg Siebert and Manfred Kietzmann

A combination of 0.1% octenidine dihydrochloride and 2% 2-phenoxyethanol (octenisept^®) is a commonly used disinfectant in human medicine. As porcine skin represents an adequate model for human skin, the effect of octenidine dihydrochloride and phenoxyethanol on wound healing is studied in pigs. Furthermore, the in vitro percutaneous permeation of the test substances is studied. The impact of the test formulations on wound healing is examined (A) under non occlusive conditions and (B) in comparison to another disinfectant based on povidone-iodine under occlusive conditions, while wounds are treated daily with the test substances. The percutaneous permeation of octenidine dihydrochloride and phenoxyethanol is studied in Franz-type diffusion cells with intact skin as well as barrier disrupted after tape stripping. Compared with povidone-iodine or vehicle treatment as well as untreated control wounds the treatment of wounds with the test formulation has no influence on the healing rate in pigs and does not induce retardation of wound healing. The in vitro diffusion experiment reveals that octenidine dihydrochloride is only detectable in the acceptor chamber of three-barrier disrupted skin samples. Phenoxyethanol permeates through intact porcine skin in amounts of 11.3% and through barrier disrupted skin in amounts of 43.9%.

The percutaneous permeation of a combination of 0.1% octenidine dihydrochloride and 2% 2-phenoxyethanol (octenisept^®) through skin of different species in vitro
Jessica Stahl, Michael Braun,Joerg Siebert and Manfred Kietzmann

Background: A water based combination of 0.1% octenidine dihydrochloride and 2% 2 - phenoxyethanol is registered in many European countries as an antiseptic solution (octenisept^®) for topical treatment with high antimicrobial activity for human use, but octenidine based products have not been registered for veterinary use yet. The aim of the present study was to investigate whether octenidine dihydrochloride or 2 -phenoxyethanol, the two main components of this disinfectant, permeate through animal skin in vitro. Therefore, permeation studies were conducted using Franz-type diffusion cells. 2 ml of the test compound were applied onto 1.77 cm2 split skin of cats, dogs, cows and horses. To simulate wounded skin, cattle skin was treated with adhesive tapes 100 times, as well. Up to an incubation time of 28 hours samples of the acceptor chamber were taken and were analysed by UV-HPLC. Using the method of the external standard, the apparent permeability coefficient, the flux Jmax, and the recovery were calculated. Furthermore, the residues of both components in the skin samples were determined after completion of the diffusion experiment.

Results: After 28 hours no octenidine dihydrochloride was found in the receptor chamber of intact skin samples, while 2.7% of the topical applied octenidine dihydrochloride permeated through barrier disrupted cattle skin. 2 - phenoxyethanol permeated through all skin samples with the highest permeability in equine, followed by bovine, canine to feline skin. Furthermore, both components were found in the stratum corneum and the dermis of all split skin samples with different amounts in the examined species.

Conclusion: For 2-phenoxyethanol the systemic impact of the high absorption rate and a potential toxicological risk have to be investigated in further studies. Due to its low absorption rates through the skin, octenidine dihydrochloride is suitable for superficial skin treatment in the examined species.

Impact of octenidine on phagocytosis of "Staphylococcus aureus" by neutrophils
Katrin Steinhauer, Peter Goroncy-Bermes

The first barrier for cationic molecules attacking gram-positive microorganisms is the cell wall and its amount of net negative charge. Modification of the cell wall by esterification of teichoic acids provides a very effective mechanism to resist such attacks up to a certain degree.

Our data demonstrates that also for the cationic octenidine dihydrochloride association with the cell wall of gram-positive bacteria is dependent on the negative net charge of the cell wall. However, even though this provides some protection our data proves, that the penetration of the biocide through the peptidoglycan layers cannot be prevented at increasing concentrations as shown by LIVE/DEAD staining, thus resulting in a lethal damage of the bacterial cells.

In addition it could be demonstrated, that interaction of octenidine dihydrochloride with the bacterial cell wall results in a significantly enhanced phagocytosis by neutrophils in human blood.

Impact of octenidine on phagocytosis of "Staphylococcus aureus" by neutrophils
Katrin Steinhauer, Peter Goroncy-Bermes

The first barrier for cationic molecules attacking gram-positive microorganisms is the cell wall and its amount of net negative charge. Modification of the cell wall by esterification of teichoic acids provides a very effective mechanism to resist such attacks up to a certain degree.

Our data demonstrates that also for the cationic octenidine dihydrochloride association with the cell wall of gram-positive bacteria is dependent on the negative net charge of the cell wall. However, even though this provides some protection our data proves, that the penetration of the biocide through the peptidoglycan layers cannot be prevented at increasing concentrations as shown by LIVE/DEAD staining, thus resulting in a lethal damage of the bacterial cells.

In addition it could be demonstrated, that interaction of octenidine dihydrochloride with the bacterial cell wall results in a significantly enhanced phagocytosis by neutrophils in human blood.

Dosage and Selection of Detergents and Disinfectants
M. Mohr

Before one can think about dosage (dose quantity) of a detergent or disinfectant, one must first of all select these products. But when making this selection one should not disregard the technical information relating to dosage (powder or liquid product; maximal possible dose quantity).

Selecting detergents and disinfectants

The choice of detergent and disinfectant will depend on a number of factors, hence the following issues must be clarified:

- What medical devices are to be processed?
- Can these be subjected to thermal disinfection (93°C) and also the thermal sterilisation
(steam sterilisation)?
- What risk is posed by the materials to be processed?
- What technical facilities are available for processing and what processing methods are to
be used?
- Is material compatibility assured, e.g. in respect of alkaline products?

The recommendations and memoranda of the Robert Koch Institute (RKI) will help to provide answers to these questions (see under References).

Risk assessment can be carried out for the medical devices to be processed by referring to the RKI recommendation "Hygiene Devices". According to this, devices are classified into uncritical, semicritical and critical, with examples of each category being given. A further distinction is made on the basis of the diverse processing requirements (A - no particular requirement; B - more stringent requirements).

This recommendation also gives preliminary information on the chemical composition of potential detergents and disinfection, while also pointing out those substances that appear to be unsuitable...

Multicentre Trial on Standardisation of a Test Soil of Practical Relevance for Comparative and Quantitative Evaluation of Cleaning Pursuant to EN ISO 15883 – Description of Test Procedure
J. Köhnlein, R. Glasmacher, V. Heide, D. Kunde, M. Mohr, D. Otto, M. Pieper, K. Roth, J. Staffeldt, P. Tiarks, S. Wagenknecht, H.-P. Werner, W. Michels

The ad hoc group ”Test soils and methods“, part of the standards committee NA Med 063-04-09 of the DIN, had reported in a previous edition of this journal initial results of a multicentre trial with an ”in vitro reference system“ for the comparative evaluation of test soils for testing the cleaning performance of washer-disinfector appliances (WD) according to EN ISO 15883-1 and ISO/TS 15883-5. Exploratory information about materials and methods was given there. This contribution now gives detailed information on the execution of the tests.

Medical Device Reprocessing as Reflected 17 Years after Introduction of the Medical Devices Act
Evaluation of the DGSV congress workshop devoted to this topic
F. Bakker, M. Schreiner, F. Böhlke

It is not just the coming into force of the Medical Devices Act (MPG), based on European Directive 93/42/EEC of 14 June 1993, that has been the chief driver of the ongoing improvements seen in the quality of medical device reprocessing and in the tightening of the requirements addressed to the users. In addition to a plethora of recommendations, guidelines and legal acts, new technologies, modern materials, devices and processes accentuate the
need for commensurately skilled users and for conductance of reprocessing in line with the state of the art in science and technology. Workshop 3 held at the German Society of Sterile Supply (DGSV) conference 2010 in Fulda, ”Medical device reprocessing as reflected 17 years after introduction of the Medical Devices Act“, focused on various stages of the instrument
circuit, with delegates expressing their views through an anonymous polling system. Simultaneous presentation and evaluation of the responses granted delegates insights into the extent to which MPG has been implemented 17 years after its introduction, while highlighting
also where there is still need for action and for further discussion. The workshop was directed in particular towards those responsible for, or working in the field of, medical device reprocessing, e. g. Central Sterile Supply Department (CSSD) or endoscopy department. This paper presents the findings of the workshop.

Introduction
Within the framework of four workshops held during the DGSV annual conference from 7 to 9 October 2010 in Fulda a total of 80 participants were surveyed for their views on medical device reprocessing and on implementation of the Medical Devices Act (MPG) within their establishment. The survey was conducted using a TED system, thus permitting anonymous evaluation of the responses. The main aim was to ascertain to what extent MPG has been implemented 17 years after its introduction. As illustrated in Figure 1, respondents consisted of a large variety of representatives of larger and smaller CSSDs.

Results
The question regarding the highest qualification in the respondent’s own CSSD showed that almost two-thirds of respondents stated that at least one person in the CSSD had successfully completed Specialist Training Course III (a training course designed for CSSD personnel). One out of every seven respondents even stated that their CSSD employed a staff member with a qualification higher than that of Specialist Training Course III. Only one respondent said that the CSSD had no qualified person.
The question as to whether a quality management system was in place in the
respondent’s own CSSD was answered with ”Yes“ by over 90 % of those surveyed. However, only in around one-third of CSSDs was the QM system certified. Although more than 90 % of respondents admitted to working in a CSSD with a quality management system, in around one out of every six CSSDs medical devices were not at all classified as per the