Evaluation of the bactericidal effect of five products for surgical hand disinfection according to prEN 12054 and prEN 12791

Surgical hand disinfection (with an alcohol-based hand rub) and surgical handwash (with an antiseptic-based liquid soap) are accepted measures to reduce the risk for surgical site infections. The new European Standards allow a comparison of their antimicrobial efficacy. The bactericidal activity of surgical hand rubs [Sterillium and Softaman, (active ingredient=alcohols)] and handwashes [Derman plus (triclosan), Hibiscrub (chlorhexidine) and Betadine (PVP-iodine)] was tested according to the prEN 12054 suspension test using Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus hirae, and to prEN 12791 for the effect on resident skin flora in comparison with 1-propanol, 60% (v/v). All five products achieved a reduction of test bacteria within 3 min of >10(5)-fold so fulfilling prEN 12054. However, only Hibiscrub, Sterillium and Softa Man met the requirements of prEN 12791, giving a mean reduction of resident micro-organisms (immediate and sustained effect) which was not significantly lower than the reference alcohol (P>0.1; Wilcoxon matched-pairs signed-rank test). Sterillium was significantly more effective than the reference alcohol (immediate and sustained affect). Products for surgical hand disinfection may have equal antimicrobial activity in suspension tests but show large differences under practical conditions. Healthcare workers should not rely on results from suspension tests when deciding on a product for surgical hand disinfection.     

Suitability of Sterillium Gel for surgical hand disinfection

In some countries, alcohol-based hand gels are used for hygienic hand disinfection but their efficacy and suitability for surgical hand disinfection has never been investigated. The efficacy of Sterillium Gel was investigated according to prEN 12791 in two separate experiments. Finger tips of 20 volunteers per experiment were sampled for resident skin bacteria before surgical hand disinfection. In a cross-over design, each volunteer carried out a surgical hand disinfection with the reference alcohol [n-propanol 60%, (v/v)] or Sterillium Gel [ethanol 85% (v/v)] for 3 min. After the product application, one hand was sampled for the immediate effect, the other hand was gloved for 3 h and then sampled for the sustained effect. Samples were analysed for remaining resident bacteria. The mean of the pre-value, the 0 h and 3 h values of the reference disinfection and the test product were calculated. With the reference alcohol, respective mean immediate log10-reduction factors of 2.06+/-0.76 and 2.23+/-1.13 were found in both experiments. The mean sustained effects with the reference alcohol were 2.03+/-1.14 and 1.44+/-0.81. Sterillium Gel achieved respective mean immediate effects of 2.48+/-1.06 and 2.13+/-0.81, the mean sustained effects were 2.77+/-0.95 and 2.18+/-0.72. They proved significantly larger than those obtained with the reference alcohol (P<0.05; pair-wise Wilcoxon test). Sterillium Gel, therefore, more than fulfils the efficacy requirements for surgical hand disinfection of prEN 12791. In addition, 25 of 26 operating theatre healthcare workers in an orthopaedic hospital found it suitable for surgical hand disinfection after a single use, which included putting on a pair of surgical gloves. Although none of them had ever used an alcohol-based gel before, they had rather been accustomed to alcohol-based liquid products for years. The main reasons given for the positive assessment were better skin feeling after use, smell and easier donning of the surgical gloves. No significant correlation was found between overall or dermal acceptance and years of professional experience, profession or number of gel portions used for surgical hand disinfection (Pearson's correlation; P>0.05).     

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.     

Comparison of two test methods for the determination of sufficient antimicrobial activity of three commonly used alcohol-based hand rubs for hygienic hand disinfection

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).     

In-vivo efficacy of hand sanitisers against feline calicivirus: a surrogate for norovirus

Hand disinfection is considered important in preventing the transmission of viruses, including norovirus. We investigated the virucidal efficacy of nine hand sanitisers (four alcohol-based sanitisers, three non-alcoholic sanitisers and two triclosan-containing antimicrobial liquid soaps) against feline calicivirus, a surrogate for norovirus, on artificially contaminated fingertips for 30 s and 2 min contact periods. Among alcohol-based sanitisers, a product containing 99.5% ethanol was more effective than those containing 62% ethanol, 70% isopropanol or 91% isopropanol. A log(10) virus reduction factor of 1.00-1.30 was achieved with 99.5% ethanol but those containing a lower alcohol concentration only achieved a log(10) reduction factor of 相似文献   

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.     

Comparison of waterless hand antisepsis agents at short application times: raising the flag of concern.

OBJECTIVE: Although alcohol-based hand rinses and gels have recommended application times of 30 to 60 seconds, healthcare workers usually take much less time for hand hygiene. We compared the efficacies of four alcohol-based hand rubs produced in Europe (hand rinses A, B, and C and one gel formulation) with the efficacy of the European Norm 1500 (EN 1500) reference waterless hand antisepsis agent (60% 2-propanol) at short application times. DESIGN: Comparative crossover study. SETTING: Infection Control Program laboratory of a large tertiary-care teaching hospital. PARTICIPANTS: Twelve healthy volunteers. INTERVENTION: Measurement of residual bacterial counts and log reduction factors following inoculation of fingertips with Staphylococcus aurens American Type Culture Collection (ATCC) 6538, Pseudomonas aeruginosa ATCC 15442, and a clinical isolate of Enterococcus faecalis. RESULTS: All hand rinses satisfied EN 1500 standards following a single application for 15 and 30 seconds, but reduction factors for the gel formulation were significantly lower for all tested organisms (all P < .025). CONCLUSIONS: Under stringent conditions similar to clinical practice, all three hand rinses proved to be more efficacious than the marketed alcohol-based gel in reducing bacterial counts on hands. Further studies are necessary to determine the in vivo efficacy of alcohol-based gels and whether they are as efficacious as alcohol-based rinses in reducing the transmission of nosocomial infections.     

Assessment of the antibacterial activity of tea tree oil using the European EN 1276 and EN 12054 standard suspension tests

The activity of tea tree oil (TTO) and TTO-containing products was investigated according to the EN 1276 and EN 12054 European suspension methods. The activity of different concentrations of TTO, a hygienic skin wash (HSW), an alcoholic hygienic skin wash (AHSW) and an alcoholic hand rub (AHR) was investigated. These formulations were assessed in perfect conditions with the EN 12054 test, and in perfect conditions as well as in the presence of interfering substances with the EN 1276 test, against Staphylococcus aureus, Acinetobacter baumannii, Escherichia coli and Pseudomonas aeruginosa. With the latter test, the activity of the same formulations without TTO was also assessed as a control. With the EN 1276 test, the AHR achieved a >10(5)-fold reduction against all four test organisms within a 1-min contact time. The AHSW achieved a >or=10(5)-fold reduction against A. baumannii after a 1-min contact time and against S. aureus, E. coli and P. aeruginosa after a 5-min contact time. The efficacy of TTO appeared to be dependent on the formulation and the concentration tested, the concentration of interfering substances and, lastly, the organism tested. Nevertheless, 5% TTO achieved a >10(4)-fold reduction in P. aeruginosa cell numbers after a 5-min contact time in perfect conditions. TTO (5%) in 0.001% Tween 80 was significantly more active against E. coli and P. aeruginosa than against S. aureus and A. baumannii. With the EN 12054 test, after a 1-min contact time, 5% TTO in 0.001% Tween 80 and the AHSW achieved a >10(4)-fold reduction in E. coli and A. baumannii cell numbers, respectively, and the AHR achieved a >4 log10 reduction against all organisms tested. The formulations used in this study are now being tested using a novel ex vivo method as well as the in vivo European standard handwashing method EN 1499.     

Tolerance and acceptability of 14 surgical and hygienic alcohol-based hand rubs

Tests were performed under working practice conditions to measure the tolerance and acceptability of commercially available hand rubs with proven efficacy. The products were compared with those in current use at the Hospices Civils de Lyon for surgical hand disinfection (Sterillium) and hygienic hand disinfection (Purell) to obtain information for public sector purchases. The 12 test products were Alcogel H, Assanis Pro, Clinogel, Dermalcool, Manugel Plus, Manugel Plus NPC, Manurub Liquid, Manurub Gel, Purell 85, Spitacid, Spitagel and Sterillium Gel. They were tested from mid-November to mid-April over four periods of three weeks, separated by two-week intervals during which the customary product was re-introduced. Participation of hospital wards and theatres was voluntary. Skin dryness and irritation were scored before and after each test period. Acceptability and ease of use were assessed by means of a questionnaire. Among the eight surgical hand rubs, only Manurub Liquid, Manurub Gel and Manugel Plus NPC did not cause significantly more dryness and irritation than Sterillium. For the 10 hygienic hand rubs, differences were noted depending upon the test period. Overall, Assanis Pro, Clinogel, Purell 85 and Sterillium Gel did not cause significantly more dryness and irritation than Purell. However, over the (colder) first three test periods, Assanis Pro and Sterillium Gel caused more irritation and Purell 85 caused more dryness than Purell. Responses to the questionnaires on acceptability indicated that users preferred their customary hand rubs (Sterillium and Purell). As these field tests involving many participants did not identify any superior products, previous purchase orders were renewed.     

Efficacy of 2 alcohol-based gels and 1 alcohol-based rinse for surgical hand disinfection.

We assessed the efficacy of 2 alcohol-based gels and 1 alcohol-based rinse for surgical hand disinfection, using European standard EN 12791. Volunteers performed surgical hand disinfection with a reference product and each of the 3 study products, with 1-week intervals between disinfection episodes. The immediate and sustained antimicrobial activities of each study product were not significantly less than those of the reference product. The study products passed the efficacy requirements of the EN 12791 standard, and they are considered suitable for surgical hand disinfection.     

Comparative review of the test design Tentative Final Monograph (TFM) and EN 12791 for surgical hand disinfectants

Preoperative antiseptic treatment of the hands of the surgical team is a standard procedure used worldwide in order to reduce the risk of surgical site infection. Two different types of antiseptics are available: alcohol-based hand rubs and antimicrobial liquid detergents ("soaps"). Standards have been developed to determine the antimicrobial efficacy of such preparations: the European norm EN 12971, finally issued in 2005, and the Tentative Final Monograph (TFM) for health care antiseptic products from 1994, which is the corresponding document in the USA. Although both methods use the reduction of resident hand flora as a quantitative parameter for antimicrobial efficacy, there are major differences concerning the test design. Whereas the European method is carried out following a randomized, reference-controlled crossover design, the US method can be characterized as a randomized, blinded parallel arm design. While both standards aim at immediate as well as sustained efficacy of the procedure, according to the EN the test product must not be significantly less effective than the reference procedure, whereas the TFM requires absolute reduction of > or = 1, > or = 2, and > or = 3 log10 per hand on days 1, 2, and 5, respectively. Results from various studies demonstrated that meeting the criteria defined by both standards may happen, but meeting the specifications of one standard does not necessarily mean that the same product will pass the requirements of the other. Missing accordance may be due to a number of considerable differences between both test methods. For a number of reasons the European method seems to be closer to clinical practice and to provide higher patient safety than the US method. However, available study data do neither allow for evaluation of the clinical impact of surgical hand disinfection as such nor of the effect of a particular product on postoperative wound infection rates.     

Hand contamination before and after different hand hygiene techniques: a randomized clinical trial

The efficacy of alcohol-based handrubs (ABH) for hand hygiene (HH) compared with handwashing (HW) remains to be established in the clinical setting. Factors associated with severe hand contamination before HH techniques were medical ward, physician and not wearing gloves. Forty-three healthcare workers [HCW, 26 nurses (N), nine nurse assistants (NA) and eight physicians (P)] each performed six HH techniques in random order, immediately after a patient care activity: HW with non-antiseptic soap for 10 (US10) and 30 (US30) s; HW with antiseptic (polyvidone iodine- or chlorhexidine-based) soap for 10 (AS10), 30 (AS30) or 60 (AS60) s; and ABH (Sterillium, Bode Chemie, Germany). The fingertips of the dominant hand were pressed on to agar for culture before and after each HH technique. Five hundred and sixteen specimens were obtained. Log(10)-transformed bacterial count reductions after HH were 0.74, 0.51, 1.13, 1.14, 1.21 and 1.40 for US10, US30, AS10, AS30, AS60 and ABH, respectively; both AS and ABH were significantly better than US. Qualitative assessment showed that 11 of the 256 pre-HH specimens (4.3%) had pathogenic bacteria, and that two of these 11 remained positive after HH (US in both instances).     

Hand disinfection according to the European Standard EN 1500 (hygienic handrub): a study with gram-negative and gram-positive test organisms.

It was the aim of this study to compare the efficacy of alcohol-based hand disinfectants according to European Standard EN 1500 (hygienic handrub), using the routine test organism Escherichia coli and, additionally, Micrococcus luteus as a surrogate for Gram-positive pathogens. One ethanol-based hand disinfectant (product A) and one propanol-based hand disinfectant (product B) were used in all experiments. Product B (propanol-based) was significantly more effective against both test organisms than product A (ethanol-based) in quantitative suspension tests but not in tests simulating practical conditions. In the experiments according to EN 1500 germ reduction rates obtained with the ethanol-containing formulation A were identical for E. coli and M. luteus. Product B was slightly, but not significantly more effective against M. luteus. To conclude, using E. coli as the test organism for evaluating the antibacterial efficacy of alcoholic hand disinfectants under practical conditions even appears to be sufficient to permit the drawing of conclusions for Gram-positive pathogens. However, more alcohol-based hand disinfectants should be tested in further studies to verify the results obtained.     

Inter-laboratory reproducibility of the hand disinfection reference procedure of EN 1500

Recent tests carried out using EN 1500 have suggested that most alcohol-based hand gels are significantly less effective than the reference alcohol [2-propanol, 60% (v/v)] whereas liquid alcohol-based hand rubs are not. However concerns about the accuracy and reproducibility of the test have been raised. We therefore analysed 41 experiments performed in four different laboratories using EN 1500 hand disinfection procedures with the reference alcohol, to analyse inter-laboratory reproducibility of the test. The mean reduction factors (difference of the log(10) of the pre-value and the post-value) from the four laboratories did not reveal a significant difference (P=0.059; analysis of variance), although the difference of the mean pre and post-values was highly significant (P<0.001). EN 1500 is a reproducible test method which leads to valid data.     

Comparison of the antibacterial efficacy and acceptability of an alcohol-based hand rinse with two alcohol-based hand gels during routine patient care

The aims of this study were to compare the antibacterial efficacy of handrubbing with an alcoholic rinse (AHRR) and two different alcoholic gels (AHRG) in reducing hand contamination under practical use conditions. We wanted to assess the acceptability of the three products and to determine the effect of each product on overall hand hygiene compliance. A prospective alternating time-series clinical trial was performed in a medical intensive care unit. The study was divided into three six-week periods (P1, P2, P3). Handrubbing was achieved with Sterillium rinse (AHRR) during P1, sterillium gel(AHRG-1) during P2 and Manugel Plus (AHRG-2) during P3. Pre- and post-rubbing hand contaminations were assessed immediately after a direct contact with a patient, using the glove juice technique. Health care workers (HCWs) evaluated the acceptability of the products through a self-administered anonymous questionnaire. Compliance of HCWs with hand hygiene was assessed during the three periods. We studied 242 handrubbing opportunities. The mean reduction factor (expressed as the Log(10) CFU/mL) of the AHRR, AHRG-1 and AHRG-2 were 1.28+/-0.95, 1.29+/-0.84 and 0.51+/-0.73, respectively (p<0.001). Assessment of the three products by HCWs indicated that AHRR and AHRG-1 were significantly better accepted than AHRG-2. The overall compliance of HCWs to hand hygiene was better when gel was available. Under practical use conditions, AHRG-1 and AHRR were more effective than AHRG-2, although all were claimed to pass the European standard EN1500. In vivo trials are essential to compare the antimicrobial efficacy of products for handrubbing.     

Efficacy of an alcohol-based healthcare hand rub containing synergistic combination of farnesol and benzethonium chloride

Healthcare workers are required to disinfect the hands several times a day using hand disinfectants, which leads to chronic hand exposure to high levels of antimicrobials contained in the disinfectants, which could compromise the skin integrity. This problem may be addressed by developing hand disinfectants containing synergistic combinations of small amounts of antimicrobials and other agents. The synergistic effect of farnesol and essential oils with several antimicrobials was studied in vitro to select an effective antimicrobial system in preservative concentration for use in healthcare hand rub. Farnesol and lemon oil showed synergistic activity against S. aureus, in combination with benzalkonium chloride and benzethonium chloride, but not with other antimicrobials studied. All essential oils studied showed synergy with benzethonium chloride against Staphylococcus aureus and Escherichia coli. An alcohol-based healthcare hand rub (ZBF hand rub) containing this unique synergistic combination of farnesol and benzethonium chloride was then developed and its efficacy as a healthcare hand rub was evaluated in human volunteers according to the US FDA-TFM protocol using Serratia marcescens as a marker organism. The ZBF hand rub showed a 3.22 log(10) reduction in the microbial count after the first application and a 5.49 log(10) reduction after the tenth application in vivo and exceeds the US FDA-TFM criteria for healthcare hand rub. The ZBF hand rub did not irritate the hands when tested on human volunteers when applied 10 times everyday for five consecutive days. The ZBF hand rub exhibits more than 5.5 log(10) reduction in the microbial count within 15s and more than 2.8 log(10) reduction in the two types of viruses tested within 30s in vitro. When evaluated in an in vitro pig skin model, the ZBF hand rub shows better prolonged activity (20-35 min post-application) against transient bacteria (S. aureus and E. coli) compared to other alcohol-based hand rubs. These findings suggest that the use of the ZBF hand rub amongst health care workers may lower the risk of chronic hand exposure to high levels of antimicrobials without compromising the efficacy.     

Antimicrobial efficacy of amine fluoride based tooth gels compared to a toothpaste in a phase 2/step 2 in-vitro test model

Introduction: The aim of the present study was to determine the antimicrobial effect of various gel formulations on plaque formation; different tooth gels were compared to a toothpaste containing comparable antimicrobial ingredients with regard to its microbiocidal activity. The study was conducted under the assumption, that a chief requirement for the prevention of plaque formation is the combination of mechanical removal and antimicrobial activity, and not the sole capability of mechanical plaque removal.Methods: Ledermix(?) fluoride gel as commercially available with preservative, and without preservative and perfume oils, Elmex(?) gelée, and Meridol(?) toothpaste were tested in a standardized in-vitro test modification of the quantitative suspension test EN 1040. Instead of testing in a suspension, the respective product was directly placed on a standardized contaminated sterile stainless steel disk without adding any bio-burden. 50% egg yolk in Aqua dest. was used as a neutralizer.Results: Within 1 min, Elmex(?) gelée showed a RF >5 log(10) against S. pyogenes and S. sanguinis. Against S. mutans, a log(10) RF of ≥5 was achieved after 2 min, against C. albicans after 5 min, and against P. aeruginosa after 10 min S. aureus was the most difficult organisms to be reduced. After an application time of 10 min, only a log(10) RF of 2.4 was achieved. Ledermix exceeded the antimicrobial efficacy of Elmex(?) gelée against S. mutans and C. albicans and was already effective against these organisms after 1 min, but did not show the same antimicrobial efficacy as Elmex(?) gelée against P. aeruginosa. Similar to Elmex(?) gelée, a required reduction of >5 log(10) for antimicrobials under no organic challenge was not achieved against S. aureus. Ledermix(?) fluoride gel without preservatives and Ledermix(?) fluoride gel without preservatives and perfume oil did not show the antimicrobial efficacy of the standard Ledermix(?) fluoride gel formulation, indicating that the observed antimicrobial efficacy is chiefly based on the preservative, and possibly the perfume oil. Compared to the tested gels, Meridol(?) toothpaste was less effective and reached any antimicrobial effect >5 log(10) only against S. sanguinis after 10 min.Conclusion: All unmodified tested gels showed an antimicrobial effect. Because no relevant antimicrobial efficacy against plaque forming bacteria was achieved within 2 min, in practice, an anti-plaque forming effect based on the antimicrobial action of gels cannot be assumed when used in the oral cavity. However, the results of the present study indicate that the antimicrobial efficacy of gels is determined by their formulation and that for the prevention of plaque formation the combination of mechanical removal and antimicrobial activity is not the chief requirement only, but a sustained antimicrobial effect may be of greater importance.     

Intra-laboratory reproducibility of the hand hygiene reference procedures of EN 1499 (hygienic handwash) and EN 1500 (hygienic hand disinfection)

The bactericidal efficacy of hand antiseptic products is determined in Europe using two norms--EN1499 (hygienic handwash), and EN 1500 (hygienic hand disinfection) based on reducing the counts of bacteria on artificially contaminated hands. Each requires 12-15 data sets per test and comparison with a reference procedure. Recent research using EN 1500 suggested that most alcohol-based hand gels are significantly less effective than the reference alcohol (2-propanol 60%), whereas liquid alcohol-based rubs are not. However concerns about the accuracy and reproducibility of the norm reference procedures have been raised. We therefore analysed 23 experiments carried out using EN 1500 representing 342 hand disinfection procedures, and 12 experiments using EN 1499 representing 178 handwashes, all performed in the same laboratory for reproducibility of the reference procedures. The reference alcohol gave a mean log(10) reduction factor (RF) of 4.64 +/- 0.93; only one data set gave a significantly higher result (5.14, P = 0.034), and one significantly lower (4.05; P = 0.034). Analysis of all 23 means revealed no significant difference (P = 0.188; ANOVA model). The reference soap gave a mean reduction of 2.82 +/- 0.49. Two data sets were significantly higher than this (3.35,P < 0.001; 3.12, P < 0.001) and two significantly lower (2.55, P = 0.031; 2.47,P = 0.004). Analysis of all the means did reveal a significant difference (P < 0.001, ANOVA model), which is probably explained by the smaller standard deviations of these results. Pre-values (bacteria recovered from fingers before a reference procedure) correlated significantly with RFs for both hand disinfection (correlation coefficient: 0.291;P = 0.01) and handwash (correlation coefficient: 0.372, P = 0.01). Overall both procedures gave accurate and reproducible results.     

Introducing alcohol-based hand rub for hand hygiene: the critical need for training.

BACKGROUND: Use of an alcohol-based hand rub for hand hygiene has recently been recommended by the Centers for Disease Control and Prevention. However, the proper technique for using hand rub has not been well described and is not routinely taught in hospitals. OBJECTIVE: To evaluate the impact of training on proper technique as outlined by the European Standard for testing alcohol-based hand rubs (European Norm 1500) in a clinical study. DESIGN, SETTING, AND PATIENTS: Prospective study including 180 healthcare workers (HCWs) in a 450-bed, university-affiliated geriatric hospital where alcohol-based hand rub was introduced in the late 1970s. INTERVENTION: Structured training program in hand hygiene with alcohol-based hand rub. Technique for using hand rub was tested by the addition of a fluorescent dye to the disinfectant and the number of areas missed was quantified by a validated visual assessment method. In addition, the number of bacteria eradicated was estimated by calculating the difference between the log(10) number of colony-forming units (cfu) of bacteria on the fingertips before and after the procedure, and reported as reduction factor (RF). MAIN OUTCOME MEASURE: Log(10) cfu bacterial counts on fingertips before and after training in the appropriate technique for using hand rub. RESULTS: At baseline, only 31% of HCWs used proper technique, yielding a low RF of 1.4 log(10) cfu bacterial count. Training improved HCW compliance to 74% and increased the RF to 2.2 log(10) cfu bacterial count, an increase of almost 50% (P<.001). Several factors, such as applying the proper amount of hand rub, were significantly associated with the increased RF. CONCLUSION: These results demonstrate that education on the proper technique for using hand rub, as outlined in EN 1500, can significantly increase the degree of bacterial killing.     

Evaluation of an alcohol-based surgical hand disinfectant containing a synergistic combination of farnesol and benzethonium chloride for immediate and persistent activity against resident hand flora of volunteers and with a novel in vitro pig skin model.

OBJECTIVE: To evaluate the immediate, persistent and sustained in vivo activity of an alcohol-based surgical hand disinfectant, consisting of a zinc gel and a preservative system containing a synergistic combination of farnesol and benzethonium chloride (ZBF disinfectant), and to develop a pig skin model for in vitro evaluation of the immediate and persistent efficacy of alcohol-based surgical hand disinfectants against resident hand flora. DESIGN: The in vivo immediate, persistent, and sustained activity of ZBF disinfectant was evaluated using human volunteers and the "glove-juice" method described in the US Food and Drug Administration's Tentative Final Monograph (FDA-TFM) for Healthcare Antiseptic Products. A novel in vitro pig skin model was developed to compare the immediate and persistent activity of alcohol-based surgical hand disinfectants against resident flora using Staphylococcus epidermidis as the test organism. Four alcohol-based surgical hand disinfectants were evaluated using this model. RESULTS: The results for the ZBF disinfectant exceed the FDA-TFM criteria for immediate, persistent, and sustained activity required for surgical hand disinfectants. The reduction factors for the 4 hand disinfectants obtained using the pig skin model show good agreement with the log(10) reductions in concentrations of hand flora obtained using human volunteers to test for immediate and persistent activity. CONCLUSION: The ZBF disinfectant we evaluated met the FDA-TFM criteria for surgical hand disinfectants. The immediate and persistent efficacy of the surgical hand disinfectants evaluated with the novel pig skin model described in this study shows good agreement with the results obtained in vivo.