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Biomedical subjects

G Kampf

Publications and source records attributed to G Kampf.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of the effectiveness of an enzymatic cleaner and glutaraldehyde-based disinfectant for chemothermal processing of flexible endoscopes in washer-disinfectors in accordance with prEN ISO 15 883.

BACKGROUND AND STUDY AIMS: This study evaluated the effectiveness of the cleaning process, the disinfection process, and a combination of the two in accordance with the new international standard, prEN ISO 15 883. MATERIALS AND METHODS: The cleaning process consisted of a 1-min prerinse at 20 degrees C, followed by a 5-min cleaning step at 45 degrees C (with an enzymatic cleaner, 0.5 %), followed by a 1-min interim rinse from 45 degrees C to 55 degrees C. The disinfection process consisted of a 1-min prerinse at 20 degrees C, followed by a 5-min disinfection step at 55 degrees C (with a glutaraldehyde-based disinfectant, 1 %), followed by two final rinses of 1 min each at 55 degrees C. Transparent test pieces were contaminated with a mixture of blood and ENTEROCOCCUS FAECIUM, and were assessed for visible cleanliness and microbial load. RESULTS: Cleaning alone, disinfection alone, and the combination of the two always led to visible cleanliness of all test pieces. The cleaning process revealed a mean reduction factor of > or = 4.6 (n = 6); the disinfection process revealed a mean reduction factor of > or = 9.0 (n = 6), and the combination of the two was found to reduce the test organism in the WD440 by 9.0 +/- 0.2 log (10) steps (n = 12) and in the AdaptaScope by 9.3 +/- 0.4 log (10) steps (n = 5). CONCLUSIONS: Overall, the entire process was found to be very effective and compatible for reprocessing flexible endoscopes in washer-disinfectors. No visible residual blood was found, despite the use of glutaraldehyde in the disinfection phase. These findings once again emphasize the importance of effective cleaning for the overall results when reprocessing flexible endoscopes.

Disinfectants↗
PubMed2006

[Optimizing surgical hand disinfection].

For more than 110 years hands of surgeons have been treated before a surgical procedure in order to reduce the bacterial density. The kind and duration of treatment, however, has changed significantly over time. Recent scientific evidence suggests a few changes with the aim to optimize both the efficacy and the dermal tolerance. Aim of this article is the presentation and discussion of new insights in surgical hand disinfection. A hand wash should be performed before the first disinfection of a day, ideally at least 10 min before the beginning of the disinfection as it has been shown that a 1 min hand wash significantly increases skin hydration for up to 10 min. The application time may be as short as 1.5 min depending on the type of hand rub. Hands and forearms should be kept wet with the hand rub for the recommended application time in any case. A specific rub-in procedure according to EN 12791 has been found to be suitable in order to avoid untreated skin areas. The alcohol-based hand rub should have a proven excellent dermal tolerance in order to ensure appropriate compliance. Considering these elements in clinical practice can have a significant impact to optimize the high quality of surgical hand disinfection for prevention of surgical site infections.

Disinfectants↗
PubMed2005

[Hygienic and dermatologic aspects of hand disinfection and prophylactic skin antisepsis].

Hygienic hand disinfection must be carried out after all patient-care activities associated with contamination risks, as well as when moving from contaminated to clean body sites, after contact with environmental surfaces in the immediate vicinity of patients, after glove removal and before aseptic procedures. Preparatory handwashing (for about 10 seconds) to mechanically remove soil and bacterial spores should be performed at least 10 minutes before surgical hand disinfection. This allows time for the normalization of increased skin hydration, a prerequisite for effective hand disinfection. Depending on the manufacturer's instructions, application times of 1.5, 3 or 5 minutes can be observed. The regular use of skin care and skin protection products can help to prevent toxic skin irritation. For skin antisepsis the recommended exposure times are > or =15 seconds before subcutaneous injections, > or =1 minute before puncture of joints and body cavities as well as preoperatively, and > or =10 minutes on skin areas rich in sebaceous glands. For all 3 indications, alcohol-based formulations are the agents of choice.

Anti-Bacterial Agents↗
PubMed2005

Surgical hand disinfection with a propanol-based hand rub: equivalence of shorter application times.

The aim of this study was to determine the efficacy of a propanol-based hand rub at application times shorter than 3 min. The bacterial pre-value was obtained from the finger tips (prEN 12791). Subjects treated their hands with the reference procedure (n-propanol, 60%) for 3 min or the product (crossover design). Sterillium was applied for 3, 2, 1.5 and 1 min. Four other preparations were tested for 1 min. Post-values (immediate effect) were taken from one hand, and the other hand was gloved for 3h. After the gloves were removed, the second post-value was taken (sustained effect). Sterillium was more effective than the reference procedure at 3, 2 and 1.5 min (immediate and sustained effect). The immediate effect after 1 min was significantly lower [mean log(10) reduction factor (RF): 1.91+/-0.90 vs. 2.52+/-0.95; P=0.001], whereas the sustained effect was not (mean RF: 1.81+/-1.06 vs. 2.05+/-1.14; P=0.204). All other preparations failed the efficacy requirement at 1 min for both the immediate and sustained effect. Using 2 x 3 mL Sterillium for a total of 1.5 min for surgical hand disinfection was at least as effective as the 3-min reference disinfection.

1-Propanol↗
PubMed2005

Efficacy of three ethanol-based hand rubs against feline calicivirus, a surrogate virus for norovirus.

We investigated the efficacy of three ethanol-based hand rubs (Sterillium Virugard, 95% ethanol; Sterillium Rub, 80% ethanol; Desderman N, 75.1% ethanol) against feline calicivirus (FCV), the surrogate virus for norovirus, on artificially contaminated hands of healthy volunteers. The ASTM E 1838-02 standard was used. Experiments were controlled with 70% ethanol and 70% propan-1-ol which were previously found to have maximal efficacy against FCV. In the first step, three different organic loads (5% fetal bovine serum, 5% faecal suspension and the tripartite ASTM load) were compared. A significant influence of the type of organic load was found (P<0.001, ANOVA). In the second step, the hand rubs were investigated with a 5% faecal suspension as a challenging organic load. The hand rub based on 95% ethanol was more effective than those based on 70% ethanol (mean log10 reduction factor: 2.17 vs. 1.56; P=0.17) and 70% propan-1-ol (mean RF: 1.63 vs. 0.95; P=0.0003). The hand rub based on 80% ethanol was also more effective than those based on 70% ethanol (mean RF: 1.25 vs. 1.03: P=0.20) and 70% propan-1-ol (mean RF: 1.43 vs. 1.09; P=0.03). The hand rub based on 75.1% ethanol was less effective than those based on 70% ethanol (mean RF: 1.07 vs. 1.27; P=0.47) and 70% propan-1-ol (mean RF: 0.78 vs. 0.97; P=0.35). Based on our data, ethanol has superior efficacy against FCV than propan-1-ol. In addition, a higher ethanol concentration in three commercially available hand rubs was associated with better efficacy against FCV.

1-Propanol↗
PubMed2005

Efficacy of various disinfectants against SARS coronavirus.

The recent severe acute respiratory syndrome (SARS) epidemic in Asia and Northern America led to broad use of various types of disinfectant in order to control the public spread of the highly contagious virus. However, only limited data were available to demonstrate their efficacy against SARS coronavirus (SARS-CoV). We therefore investigated eight disinfectants for their activity against SARS-CoV according to prEN 14476. Four hand rubs were tested at 30s (Sterillium, based on 45% iso-propanol, 30% n-propanol and 0.2% mecetronium etilsulphate; Sterillium Rub, based on 80% ethanol; Sterillium Gel, based on 85% ethanol; Sterillium Virugard, based on 95% ethanol). Three surface disinfectants were investigated at 0.5% for 30 min and 60 min (Mikrobac forte, based on benzalkonium chloride and laurylamine; Kohrsolin FF, based on benzalkonium chloride, glutaraldehyde and didecyldimonium chloride; Dismozon pur, based on magnesium monoperphthalate), and one instrument disinfectant was investigated at 4% for 15 min, 3% for 30 min and 2% for 60 min [Korsolex basic, based on glutaraldehyde and (ethylenedioxy)dimethanol]. Three types of organic load were used: 0.3% albumin, 10% fetal calf serum, and 0.3% albumin with 0.3% sheep erythrocytes. Virus titres were determined by a quantitative test (endpoint titration) in 96-well microtitre plates. With all tested preparations, SARS-CoV was inactivated to below the limit of detection (reduction factor mostly > or =4), regardless of the type of organic load. In summary, SARS-CoV can be inactivated quite easily with many commonly used disinfectants.

Animals↗
PubMed2005

Suitability of the German test method for cleaning efficacy in washer-disinfectors for flexible endoscopes according to prEN ISO 15883.

In Europe, the evaluation of processing flexible endoscopes in washer-disinfectors (WDs) is performed in compliance with prEN ISO 15883-1 which includes determination of the efficacy of the cleaning process. Recent data suggest that cleaning processes show large differences when the prEN ISO 15883-1 German test model is applied. Hence, we analysed a total of 72 experiments in order to evaluate the test method. Transparent test tubes as test pieces (length 2 m, lumen 2 mm) were contaminated with a mixture of blood and Enterococcus faecium. Three set-ups were used: WD 425 with soft water, WD 425 with hard water and WD 440 with demineralized water. WDs were set to perform the cleaning stage of the programme alone. Seven cleaning agents were used according to the manufacturers' instructions (21 cleaning processes); in addition, three cleaning processes were carried out without a cleaning agent (i.e. with water alone). Each cleaning process was assessed by means of three experiments. Suspensions of test organism had 9.2x10(10) colony-forming units (cfu)/mL E. faecium (mean of 24 processes). Controls (recovery) contained 1.0x10(6) cfu/mL E. faecium (mean of 71 experiments). Mean log(10) reduction factors (RFs) for each process, i.e. the difference in microbial loads on the control and the processed tubes, were calculated. Cleaning processes led to RFs of 0-4.1, but no process led to residual bacterial loads below the limit of detection (1.8l gcfu/mL). Standard deviations for a cleaning process were small (< or =0.6 in 79% of the processes) indicating adequate reproducibility. The test model led to reproducible results and revealed large differences between the individual processes. If a cleaning process is intended to result in a bioburden reduction (i.e. RF> or =4), the control must carry a minimum bioburden of 6.5x10(5) cfu/mL. This was achieved in 58% of the processes. However, controls with a bioburden <6.5x10(5) cfu/mL never yielded a residual bacterial load below the limit of detection. We found that the prEN ISO 15883-1 German test method is suitable to determine the cleaning efficacy in WDs and leads to reproducible and valid results.

Decontamination↗
PubMed2004

The six golden rules to improve compliance in hand hygiene.

Improvement of compliance in hand hygiene is probably the most effective step in reducing the incidence of nosocomial infections (NI). But improvement of compliance is known to be complex. Six possibilities for improving compliance are available although some of them may be difficult to carry out. Rule 1: Select an alcohol-based hand rub which has a good skin tolerance and is acceptable to health care workers to use. This has been shown to improve compliance. Rule 2: The hand rub shall be easily available. Wall dispensers near the patient and pocket bottles may well help. Other possibilities should be assessed locally. Rule 3: Implement teaching and promotion of hand hygiene, which has been shown to be very effective. This is may be the most effective tool but will cost time and money. If money is a problem, rule 4 may be the solution. Rule 4: Create a hospital budget which covers all costs involved with preventable nosocomial infection. Combine it with the budget for hand hygiene products. Even a small number of prevented NI largely outweighs the cost of effective hand hygiene products. Rule 5: Get senior staff to set a good example in order to motivate junior staff, because negligence in hand hygiene appears to correlate with the number of professional years. Rule 6: Have the patient-staff ratio well balanced. It has been shown that staff shortage decreases hand hygiene compliance. Other factors may be important as well, but implementation of these 6 golden rules could be an effective step into the right direction.

Cross Infection↗
PubMed2004

Efficacy of alcohol-based gels compared with simple hand wash and hygienic hand disinfection.

A recent research letter on the limited efficacy of alcohol-based hand gels has alerted the global infection control community and raised the question of the true significance of data obtained according to EN 1500. It has been described that a 1 min simple hand wash reduces artificial contamination of hands by a log(10) reduction factor of 2.8 and a 1 min reference hand disinfection with 2-propanol (60%, v/v) by a factor of 4.6 steps. The EN 1500 gel data show that the 30 s efficacy of most gels is closer to a simple hand wash than to the reference hand disinfection. The 30 s efficacy of most alcohol-based liquid products and one gel, however, is almost identical to the reference hand disinfection. In many European countries alcohol-based liquid products have been established as a standard practice in hygienic hand disinfection for decades. Replacement of these products with most available gels would be a step backward in terms of efficacy and has still to be seen critically from the efficacy point of view.

Anti-Infective Agents, Local↗
PubMed2004

Test models to determine cleaning efficacy with different types of bioburden and its clinical correlation.

The importance of cleaning as a first crucial step in reprocessing instruments and endoscopes is recognized worldwide. However, no standards to determine the efficacy of cleaning have been established. We have therefore investigated Bodedex forte, a new cleaner, in various test models derived from critical types of bioburden on flexible endoscopes. Removal of dried blood from metal carriers was determined in comparison with standard instrument disinfectants. Removal of biofilm endotoxin from silicone test pieces and removal of dried X-ray contrast medium from polyethylene pieces was measured in comparison with one other standard cleaner. Residual bacteria in a biopsy channel from duodenoscopes following use of Bodedex forte, compared with two other cleaners, were measured in an endoscopy unit. After 15 min exposure to Bodedex forte, 95% of the dried blood were removed. Removal was between 0 and 86% with the disinfectants. Bodedex forte reduced endotoxin by 1.91+0.19 log(10)-steps compared with 0.43+0.19 log(10)-steps Cidezyme (P < 0.001) two-sided t-test). Removal of dried X-ray contrast medium was 99% with Bodedex forte and 94% with a conventional cleaner. No bacterial contamination after reprocessing was found in 98% of duodenoscopes with Bodedex forte (78 duodenoscopes), in 72% with a conventional cleaner (129 duodenoscopes) and in 69% with an enzymatic cleaner (100 duodenoscopes). The difference between the three cleaners was significant (P < 0.001) chi-squared test). The superiority of the cleaning capacity of the new cleaner was demonstrated in various test models, which were designed according to the clinical relevance of different bioburdens. Implementation of accepted and reproducible standards for testing the cleaning efficacy will remain a goal for the next years.

Biofilms↗
PubMed2004

Assessment of new chemical disinfectants for HBV virucidal activity in a cell culture model.

Several new chemical disinfectants were processed for Hepatitis B virus (HBV) virucidal activity in a cell culture model. A pooled HBV infected human plasma with 10(10.4) HBV DNA copies/mL was treated with the tested disinfectant. It was then subjected, for three days at several dilutions, to cell culture using the human hepatoma cell line, HepG2, with 4% polyethyleneglycol and 3 mM sodium butyrate. Thirty-seven assays were performed on 12 products, with up to 3 concentrations and 3 time exposures for each product tested. The mean viral titre without disinfectant was 10(5.18) infectious units per mL. Our results showed that products all four hand rubs examined, two of the three surface disinfectants and two of the three instrument disinfectants were highly active whatever concentrations and time exposures, reducing viral times by factors of 10(3)-10(4). However, other products such as one of the surface disinfectants was only active at concentrations above 0.5% for 15 min. Similarly the skin disinfectant, one of the instrument disinfectants and the hand wash agent (diluted to 50%) were less or not active (of <10(3) fold reduction). This is the first study using a cell culture model to assess virucidal activity against HBV of new disinfectants. It showed that most 9/12 products were active by either HBs antigen alteration (8/9) or probable envelope disruption (1/9). Further studies are in progress using this model to assess the activity of other chemical disinfectants such as peracetic acid against HBV.

Cell Line↗
PubMed2004

Surface fixation of dried blood by glutaraldehyde and peracetic acid.

The difficulties of successful prion inactivation by chemical agents has led to changes in recommendations regarding the reprocessing of instruments including flexible endoscopes. One of the changes is the preference for peracetic acid instead of glutaraldehyde in order to avoid fixation of organic material, but the surface fixation by various active agents has not been fully investigated. We used a standardized amount of dried blood soil on metal carriers (on average 22 mg). One part of the carriers was exposed to different disinfectants (four based on peracetic acid, three based on glutaraldehyde, two based on quaternary ammonium compounds (QAC), one based on QAC and amines, one based on phenols and one cleaning agent) and air dried. The difference compared with the non-exposed soiled carrier was taken as the measure of blood removal by exposure to the disinfectants. In addition the other part of the carriers was exposed to a cleaning agent and air dried. The cleaning agent itself was capable of removing more than 99% of the dried blood and served as a control for non-fixation. The rate of fixation of dried blood was calculated as the ratio of the weight of residual soil on 'soiled, disinfected and cleaned' carriers and on 'soiled and disinfected' carriers. All experiments were repeated eight times. Blood removal varied between 90.3% +/- 1.5% (phenol-based disinfectant) and < 10% (glutaraldehyde-based preparations). Fixation of the remainder was between 76.9 +/- 8.4% and 102.5 +/- 1.1% with glutaraldehyde and between 19.2% +/- 3.3% and 78.1% +/- 2.4% with peracetic acid. No other preparations showed a potential for blood fixation (< 1.3%). Our findings underline the potential for blood fixation, not only by glutaraldehyde, but also by peracetic acid, and support the evidence that effective cleaning should precede the chemical disinfection.

Blood↗