Evaluation of two methods of determining the efficacies of two alcohol-based hand rubs for surgical hand antisepsis

A Randomized Controlled Trial of Animal-assisted Activities for Pediatric Oncology Patients: Psychosocial and Microbial Outcomes

INTRODUCTION

Evidence about the effectiveness and safety of dog visits in pediatric oncology is limited.

METHOD

We conducted a randomized controlled trial (n=26) of dog visits versus usual care among pediatric oncology inpatients. Psychological functioning and microbial load from hand wash samples were evaluated. Parental anxiety was a secondary outcome.

RESULTS

We did not observe a difference in the adjusted mean present functioning score (-3.0; 95% confidence interval [CI], -12.4 to 6.4). The difference in microbial load on intervention versus control hands was -0.04 (95% CI, -0.60 to 0.52) log10 CFU/mL, with an upper 95% CI limit below the prespecified noninferiority margin. Anxiety was lower in parents of intervention versus control patients.

DISCUSSION

We did not detect an effect of dog visits on functioning; however, our study was underpowered by low recruitment. Visits improved parental anxiety. With hand sanitization, visits did not increase hand microbial levels.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov NCT03471221.

Development and Implementation of an Ultraviolet-Dye-Based Qualification Procedure for Hand Washing and Disinfection to Improve Quality Assurance of Pharmacy Preparations and Compounding, Especially in Cleanrooms: A Pilot Study

Even though, nowadays, most medicines are manufactured industrially, patients may have medical needs that can only be met by a tailor-made approach. This requires the availability of pharmacy preparations made under Good Manufacturing Practice (GMP) conditions. An efficient hand hygiene practice is essential herewith, especially if sterile products that are prepared in a cleanroom are concerned. The effectiveness of hand washing and hand disinfection procedures greatly relies on adequate training. We carried out an observational cross-sectional pilot study aimed at optimizing hand hygiene training with objective and measurable quality assessments using an ultraviolet (UV) dye. Practical acceptance criteria for qualifying personnel through this method were set and evaluated. In total, 25 GMP-qualified cleanroom operators washed and disinfected their hands with UV dye hand wash lotion and UV dye hand alcohol, respectively. To obtain a proof-of-concept, the results were judged based on adherence to the WHO six-step protocol and associated acceptance criteria. Commonly missed areas were brought to light, and the influence of procedure duration was investigated. UV-dye-based assessments appeared to be more valuable in hand disinfection than in hand washing. In both procedures, the back of the hands and the thumbs were frequently missed. This underpins the need for enhanced and repeated education on hand washing and disinfection. Additionally, a dry skin gave rise to extra cleaning challenges. From this pharmacy practice pilot study with a focus on pharmaceutical product care, it may be concluded that the application of UV-dye-based assessments offers valuable insights for pharmacists to optimize hand hygiene, thereby increasing the safety of tailor-made medicines and on-site preparations.

Longevity of hand sanitisers on fingers

CLINICAL RELEVANCE

Hand hygiene is important to reduce the spread of microbes in clinical settings. Hand sanitisers that last longer may be beneficial.

BACKGROUND

Longevity of hand sanitisation products on fingers and hands may be important to help reduce microbial transmission. The current study evaluated the persistence of disinfection of three hand sanitisers.

METHODS

Initially the minimum inhibitory concentrations of the hand sanitisers were determined using strains of Staphylococcus epidermidis and S. aureus. Then a cross-over study with participants randomly assigned to use three different hand sanitisers for 30 seconds was undertaken. The number of bacteria and fungi on fingers was assessed 10 and 20 minutes and 4 hours after use. The type of microbial inhibition of the capric acid sanitiser was studied by examining the effects of adding Tween 80 and lecithin to microbial agar.

RESULTS

The minimum inhibitory concentration of an alcohol-based sanitiser (AS) was 10%, for the capric acid-based (CS) sanitiser was 70%, and for the quaternary ammonium-based (QS) sanitiser was < 10%. AS significantly reduced the number of microbes on fingers 10 minutes after hand washing (18.2 cfu/mL) compared to CS (59.7 cfu/mL; p < 0.0001) or QS (64.5 cfu/mL; p < 0.0001). Twenty minutes after use, microbes on fingers after AS (23 cfu/mL) or CS (16.7 cfu/mL) were significantly reduced compared to QS (72.2  cfu/mL; p < 0.0001) and the numbers on fingers after CS was significantly less than after AS (p = 0.002). Four hours after use of any hand sanitiser, the number of microbes increased to near baseline levels. The reduction in bacterial numbers was not affected by the use of neutralisers in agar (48 ± 28% reduction with, 47 ± 49% reduction without; p = 0.876).

CONCLUSIONS

Hand sanitisers containing capric acid or alcohol out-performed one containing quaternary ammonium in the clinical trial and may help reduce the spread of microbes.

Electronic Monitoring Systems for Hand Hygiene: Systematic Review of Technology

BACKGROUND

Hand hygiene is one of the most effective ways of preventing health care-associated infections and reducing their transmission. Owing to recent advances in sensing technologies, electronic hand hygiene monitoring systems have been integrated into the daily routines of health care workers to measure their hand hygiene compliance and quality.

OBJECTIVE

This review aims to summarize the latest technologies adopted in electronic hand hygiene monitoring systems and discuss the capabilities and limitations of these systems.

METHODS

A systematic search of PubMed, ACM Digital Library, and IEEE Xplore Digital Library was performed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies were initially screened and assessed independently by the 2 authors, and disagreements between them were further summarized and resolved by discussion with the senior author.

RESULTS

In total, 1035 publications were retrieved by the search queries; of the 1035 papers, 89 (8.60%) fulfilled the eligibility criteria and were retained for review. In summary, 73 studies used electronic monitoring systems to monitor hand hygiene compliance, including application-assisted direct observation (5/73, 7%), camera-assisted observation (10/73, 14%), sensor-assisted observation (29/73, 40%), and real-time locating system (32/73, 44%). A total of 21 studies evaluated hand hygiene quality, consisting of compliance with the World Health Organization 6-step hand hygiene techniques (14/21, 67%) and surface coverage or illumination reduction of fluorescent substances (7/21, 33%).

CONCLUSIONS

Electronic hand hygiene monitoring systems face issues of accuracy, data integration, privacy and confidentiality, usability, associated costs, and infrastructure improvements. Moreover, this review found that standardized measurement tools to evaluate system performance are lacking; thus, future research is needed to establish standardized metrics to measure system performance differences among electronic hand hygiene monitoring systems. Furthermore, with sensing technologies and algorithms continually advancing, more research is needed on their implementation to improve system performance and address other hand hygiene-related issues.

Surgical hand preparation in an equine hospital: Comparison of general practice with a standardised protocol and characterisation of the methicillin-resistant Staphylococcus aureus recovered

Presurgical hand asepsis is part of the daily routine in veterinary medicine. Nevertheless, basic knowledge seems to be low, even among specialised veterinary surgeons. The major objectives of our study were to assess current habits for presurgical hand preparation (phase 1) among personnel in a veterinary hospital and their effectiveness in reducing bacteria from hands in comparison to a standardised protocol (phase 2). Assessment of individual habits focused on time for hand washing and disinfection, the amount of disinfectant used, and the usage of brushes. The standardised protocol defined hand washing for 1 min with liquid neutral soap without brushing and disinfection for 3 min. All participants (2 surgeons, 8 clinic members, 32 students) used Sterillium®. Total bacterial counts were determined before and after hand washing, after disinfection, and after surgery. Hands were immersed in 100 ml sterile sampling fluid for 1 min and samples were inoculated onto Columbia sheep blood agar using the spread-plate method. Bacterial colonies were manually counted. Glove perforation test was carried out at the end of the surgical procedure. Differences in the reduction of relative bacterial numbers between current habits and the standardised protocol were investigated using Mann-Whitney-Test. The relative increase in bacterial numbers as a function of operation time (≤60 min, >60 min) and glove perforation as well as the interaction of both was investigated by using ANOVA. Forty-six and 41 preparations were carried out during phase 1 and phase 2, respectively. Individual habits differed distinctly with regard to time (up to 8 min) and amount of disinfectant (up to 48 ml) used both between participants and between various applications of a respective participant. Comparison of current habits and the standardised protocol revealed that the duration of hand washing had no significant effect on reducing bacteria. Contrary, the reduction in bacterial numbers after disinfection by the standardised protocol was significantly higher (p<0.001) compared to routine every-day practice. With regard to disinfection efficacy, the standardised protocol completely eliminated individual effects. The mean reduction in phase 1 was 90.72% (LR = 3.23; right hand) and 89.97% (LR = 3.28; left hand) compared to 98.85% (LR = 3.29; right hand) and 98.92% (LR = 3.47; left hand) in phase 2. Eight participants (19%) carried MRSA (spa type t011, CC398) which is well established as a nosocomial pathogen in veterinary clinics. The isolates could further be assigned to a subpopulation which is particularly associated with equine clinics (mainly t011, ST398, gentamicin-resistant). Glove perforation occurred in 54% (surgeons) and 17% (assistants) of gloves, respectively, with a higher number in long-term invasive procedures. Overall, bacterial numbers on hands mainly increased over time, especially when glove perforation occurred. This was most distinct for glove perforations on the left hand and with longer operating times. Our results demonstrate that standardised protocols highly improve the efficacy of hand asepsis measures. Hence, guiding standardised protocols should be prerequisite to ensure state-of-the-art techniques which is essential for a successful infection control intervention.

Development of amoxicillin resistance in Escherichia coli after exposure to remnants of a non-related phagemid-containing E. coli: an exploratory study

Objective

To determine the effect of exposure to remnants of a phagemid-containing E. coli, killed by treatment with a propanol-based hand rub, on antimicrobial resistance in E. coli isolates.

Methods

An in vitro model was developed in which a clinical E. coli isolate (EUR1) was exposed to remnants of an E. coli K-12 strain containing a phagemid (pBS-E12) strain treated with Sterillium®. A series of 200 experiments was performed using this in vitro model. As a control, a series of 400 experiments was performed where the EUR1 was exposed either to the remnants of an E. coli K-12 strain (not containing a phagemid) (E12) treated with Sterillium® (n = 200) or to dried Sterillium® only (n = 200). The number of experiments that showed growth of an amoxicillin-resistant EUR1 isolate was evaluated in all three groups. An additional 48 experiments were performed in which a different clinical E. coli isolate (EUR2) was exposed to remnants of the pBS-E12 treated with Sterillium®. Whole-genome sequencing and phenotypic testing for AmpC beta-lactamase production was performed to investigate the mechanism behind this resistance development.

Results

In 22 (11.0%) of 200 experiments in which the EUR1 isolate was exposed to remnants of a pBS-E12 an amoxicillin-resistant mutant isolate was obtained, as opposed to only 2 (1.0%) of 200 experiments involving the exposure of the EUR1 to Sterillium® only (risk difference: 10.0%; 95% CI 5.4–14.6%)) and 1 (0.5%) of 200 experiments involving the exposure of the EUR1 isolate to the remnants of the phagemid-free E12 (risk difference: 10.5%; 95% CI 6.1–14.9%). In 1 (2.1%) of the 48 experiments in which the EUR2 isolate was exposed to remnants of a pBS-E12 an amoxicillin-resistant mutant isolate was obtained. The development of resistance in all experiments was due to mutations in the promoter/attenuator region of the chromosomal AmpC beta-lactamase (cAmpC) gene leading to cAmpC hyperproduction.

Conclusion

Exposure of an E. coli isolate to another phagemid-containing E. coli that was treated with propanol-based hand rub increased the development of amoxicillin resistance. Although phagemids are cloning vectors that are not present in clinical isolates, this finding may have implications for hand disinfection practices in healthcare facilities.

Operating Room Hand Preparation: To Scrub or to Rub?

BACKGROUND

The alcohol rub has been proposed as an alternative to the traditional surgical scrub in preparing the hands for surgical procedures. Few reviews have examined critically the evidence that favors or discredits the use of the alcohol rub instead of the traditional scrub.

METHODS

A review of available published literature was undertaken to define the evidence for the best methods for hand preparation before surgical procedures. The focus of this literature review was to compare the bacteriologic and clinical outcomes of conventional surgical scrubbing of the hands compared with alcohol rubs.

RESULTS

The bacteriologic studies of the hands after the conventional scrub versus the alcohol rub demonstrated consistently comparable or superior reductions in bacterial presence on the hand with the alcohol rub. Only four clinical studies were identified that compared the scrub versus the rub in the frequency of surgical site infections. No difference in surgical site infections were identified.

CONCLUSIONS

The alcohol rub appears to have comparable results to the surgical scrub and is a reasonable alternative in preparation of the hands for surgical procedures.

Efficacy of application of an alcohol-based antiseptic hand rub or a 2% chlorhexidine gluconate scrub for immediate reduction of the bacterial population on the skin of dogs

OBJECTIVE To compare the efficacy of application of an alcohol-based antiseptic (80% ethyl alcohol) hand rub (ABAHR) with that of a 2% chlorhexidine gluconate scrub (CGS2) for immediate reduction of the bacterial population on the skin of dogs. ANIMALS 50 client-owned dogs with no evidence of skin disease. PROCEDURES On each dog, 2 areas of hair on the ventral aspect of the abdomen were clipped with a No. 40 blade and cleared of debris. A direct contact plate holding tryptic soy agar with polysorbate 80 and lecithin was gently pressed (for 2 seconds) on each skin site (preapplication sample). The CGS2 and ABAHR were each aseptically applied to 1 skin site on each dog. A direct contact plate was subsequently applied to each site in a similar manner (postapplication sample). All plates were cultured, and bacterial isolates were identified and quantified by the number of CFUs per plate. RESULTS Application of the CGS2 and ABAHR significantly decreased skin bacterial colony counts, compared with findings for preapplication samples. The number of CFUs per plate or postapplication percentage reduction in CFUs per plate did not differ between treatments. There were no adverse skin reactions associated with either application. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that applications of ABAHR and CGS2 were equally effective at immediately reducing the bacterial population on the skin of dogs, and there was no significant difference in percentage reduction in colony counts between the 2 applications.

Healthcare workers' hands as a vehicle for the transmission of virulent strains of Candida spp.: A virulence factor approach

BACKGROUND

Although the majority of Candida infections are thought to come from endogenous sources, the healthcare workers' (HCWs) hands are being increasingly reported as vehicles for the transmission of pathogens. The aim of the present study was to evaluate the susceptibility of yeast isolated from the HCWs' hands and ICU (Intensive Care Unit) surfaces to antifungal agents and to determine the virulence potential and the genetic similarity between the same.

METHODS

The susceptibility of yeasts from the HCWs' hands (n = 57) and ICU surfaces (n = 98) to conventional antifungals (fluconazole, voriconazole, amphotericin B and micafungin) was evaluated using the broth microdilution assay accordance with CLSI M27-A3. Additionally, some virulence factors such as adhesion and biofilm capacity on abiotic surfaces and on endothelial cells were evaluated, as well as germ tube formation. The similarity among yeast isolates were evaluated by the RAPD technique using the P4, OPA18 and OPE18 primers.

RESULTS

Five species of Candida were found on the HCWs' hands (C. albicans, C. parapsilosis (sensu stricto), C. glabrata, C. tropicalis and C. krusei) and two on ICU surfaces (C. albicans and C. parapsilosis (sensu stricto)). The isolates from hands had higher resistance rates, with C. glabrata having the highest indices (100% FLU; 100% MFG). The similarity of C. albicans from HCWs and ICU surfaces was ≥80% according to the three primers analyzed. Candida spp. from hands had a greater potential for adhesion and biofilm formation on abiotic surfaces (p < 0.05). C. albicans from ICU surfaces had the greatest potential of adhesion on endothelial cells after 2 and 24 h, and presented high filamentation in SEM images and formed more and larger germ tubes (p < 0.05).

CONCLUSION

the present study showed the significant virulence potential of yeasts transmitted in the hospital environment for the first time. Additionally, healthy people working in the ICU can carry these yeasts, which are capable of surviving in hospital surfaces, on their hands, offering a risk to patients, especially those who are immunocompromised.

Chlorhexidine is not an essential component in alcohol-based surgical hand preparation: a comparative study of two handrubs based on a modified EN 12791 test protocol

BACKGROUND

Surgical hand preparation is an essential part of modern surgery. Both alcohol-based and antiseptic detergent-based hand preparation are recommended practices, with a trend towards use of alcohol based handrubs. However, discussion has arisen whether chlorhexidine is a required ingredient in highly efficacious alcohol-based formulations, in view of providing sustained antimicrobial efficacy.

METHODS

One alcohol-only formulation (product A), containing ethanol and n-propanol, and one formulation containing a chlorhexidine-ethanol combination (product B) were directly compared with each other using a modified test protocol based on European standard EN 12791 (2016) with 25 volunteers. The alcohol-only formulation (product A) was applied for only 90 s, the chlorhexidine-alcohol formulation (product B) for 180 s. Microbial log reduction factors were determined and statistically compared immediately after application and at 6 h under surgical gloves.

RESULTS

The alcohol-only formulation (product A) achieved mean log reduction factors of 1.96 ± 1.06 immediately after application and 1.67 ± 0.71 after 6 h. The chlorhexidine-alcohol combination (product B) achieved mean log reduction factors of 1.42 ± 0.79 and 1.24 ± 0.90 immediately and after 6 h, respectively. The values for product A were significantly greater than those for product B at both measured time points (p ≤ 0.025 immediately after application and p ≤ 0.01 after 6 h).

CONCLUSIONS

An optimized alcohol-only formulation tested according to a modified EN 12791 protocol in 25 healthy volunteers outperformed a chlorhexidine-alcohol formulation both immediately after application and at 6 h under surgical gloves, despite a much shorter application time. Thus, optimized alcohol-only formulations do not require chlorhexidine to achieve potent immediate and sustained efficacy. In conclusion, chlorhexidine is not an essential component for alcohol-based surgical hand preparation.

Baby Shampoo Versus Povidone-Iodine or Isopropyl Alcohol in Reducing Eyelid Skin Bacterial Load

PURPOSE

Baby shampoo is used as an alternative surgical skin preparation, but the evidence supporting its use is scarce with no descriptions of efficacy in the periocular region. The authors compare the efficacy of baby shampoo, povidone-iodine (PI, Betadine) and isopropyl alcohol (IA) in reducing eyelid skin bacterial load.

METHODS

Prospective, randomized, comparative, and interventional trial. Bacterial load on adult, human eyelid skin was quantitated before and after cleansing with 1) dilute baby shampoo, 2) 10% PI, or 3) 70% IA. Paired skin swabs were collected from a 1 cm area of the upper eyelid of subjects before and after a standardized surgical scrub technique. Samples were cultured on 5% sheep blood agar for 24 hours. The number of colony forming units (CFU) was assessed and bacterial load per square centimeter of eyelid skin was quantified.

RESULTS

Baseline and postcleansing samples were assessed from 42 eyelids of 42 subjects (n = 14 for each of baby shampoo, PI, and IA). Before cleansing, similar amounts of bacterial flora were grown from all specimens (median log CFU/cm = 2.04 before baby shampoo, 2.01 before PI, 2.11 before IA; p > 0.05). All 3 cleansing agents significantly reduced the bacterial load (p < 0.01 for each). There was no statistically significant difference in postcleansing bacterial load between the 3 cleansing agents (median log CFU/cm = 0.48 after baby shampoo, 0.39 after PI, 0.59 after IA; p > 0.05). Change from baseline in bacterial load was statistically similar for all 3 agents (median reduction in log CFU/cm = 1.28 with baby shampoo, 1.57 with PI, 1.40 with IA; p > 0.05). These corresponded to bacterial load reductions of 96.3%, 96.6%, and 98.4% for baby shampoo, PI, and IA, respectively.

CONCLUSIONS

Baby shampoo achieved comparable diminution in eyelid skin bacterial load to PI or IA. These data suggest baby shampoo may be an effective preoperative cleansing agent.

Carriage of Multidrug Resistant Bacteria on Frequently Contacted Surfaces and Hands of Health Care Workers

INTRODUCTION

Maximal contact between the patients and Health Care Workers (HCWs) happens in the Intensive Care Units (ICU). Control of nosocomial infections requires compliance with hand hygiene and contamination free surfaces.

AIM

To determine the colonization of potential pathogens in the hands of HCWs and frequent contacted environmental surfaces.

MATERIALS AND METHODS

A cross sectional study was conducted between September 2012 and May 2013 at Sri Ramachandra Medical College and Hospital. A total of 327 samples were collected using Glove juice technique from hands and swabs from frequently contacted surfaces. A sum of 157 samples were collected by glove juice technique from the hands of HCWs which included Consultants (20), Internees (3), Residents (10), Staff nurse (102) and support staff (22). A total of 170 samples were collected through swabbing which included frequently touched surfaces of apron and dress (140 which included 10 consultants, 3 internees, 9 Residents, 101 Staff nurse and 17 support staff), 9 door handle, 4 key board, 12 tap handles and 5 monitors. The samples were inoculated into Blood agar, Chocolate agar and Mac-Conkey agar plates and incubated at 37(0)C aerobically. The plates showing growth were further processed to identify the organisms by Gram staining and biochemical reactions. Antibiotic susceptibility testing was done for the isolates by Kirby-baur disc diffusion method as per CLSI guidelines.

RESULTS

Out of the 157 hand sampling done by glove juice method 67(42.7%) of them showed growth and 90(57.3%) showed no growth. The potential pathogens grown were 13 (8.3%), consisting of Methicillin Sensitive Staphylococcus aureus (MSSA) 6(3.8%), Methicillin Resistant Staphylococcus aureus (MRSA) 2(1.3%), Pseudomonas spp 4(2.6%) and Acenitobacter spp 1 (0.6%). The MRSA was seen in Consultant 1(5%; n=20) and Staff nurse 1(0.9%; n= 102). Among the 140 sampling from the dress of HCWs growth was observed in 69(49.3%) and growth was absent in 71(50.7%). The potential pathogens observed were 14(10%) and they are MSSA 5(3.6%), MRSA 1 (0.7%), Pseudomonas spp 2(1.4%), Acenitobacter spp 3(2.1%) Enterobacter spp 1(0.7%), Klebseilla pneumoniae 1(0.7%) and Candida spp 1(0.7%). One MRSA was isolated from staff nurse (0.9%; n=101). Similarly multi-drug resistant Klebsiella pneumoniae 1(0.9%; n=102). Out of the 30 environmental samples 16(53.3%) showed growth and in 14(56.7%) growth was absent. The potential pathogens isolated were 3(10%) which included MSSA 2(6.6%) and MRSA 1(3.4%) and were isolated from the monitor.

CONCLUSION

Adherence to infection control practices among all categories of HCWs is must for control of HAI. Glove juice method is a simple, easy and practical technique for determination of colonization of hands of HCWs and can be adapted as a methodology for screening the hands of HCWs.

A Pragmatic Randomized Controlled Trial of 6-Step vs 3-Step Hand Hygiene Technique in Acute Hospital Care in the United Kingdom

OBJECTIVE

To evaluate the microbiologic effectiveness of the World Health Organization’s 6-step and the Centers for Disease Control and Prevention’s 3-step hand hygiene techniques using alcohol-based handrub.

DESIGN

A parallel group randomized controlled trial.

SETTING

An acute care inner-city teaching hospital (Glasgow).

PARTICIPANTS

Doctors (n=42) and nurses (n=78) undertaking direct patient care.

INTERVENTION

Random 1:1 allocation of the 6-step (n=60) or the 3-step (n=60) technique.

RESULTS

The 6-step technique was microbiologically more effective at reducing the median log10 bacterial count. The 6-step technique reduced the count from 3.28 CFU/mL (95% CI, 3.11–3.38 CFU/mL) to 2.58 CFU/mL (2.08–2.93 CFU/mL), whereas the 3-step reduced it from 3.08 CFU/mL (2.977–3.27 CFU/mL) to 2.88 CFU/mL (−2.58 to 3.15 CFU/mL) (P=.02). However, the 6-step technique did not increase the total hand coverage area (98.8% vs 99.0%, P=.15) and required 15% (95% CI, 6%-24%) more time (42.50 seconds vs 35.0 seconds, P=.002). Total hand coverage was not related to the reduction in bacterial count.

CONCLUSIONS

Two techniques for hand hygiene using alcohol-based handrub are promoted in international guidance, the 6-step by the World Health Organization and 3-step by the Centers for Disease Control and Prevention. The study provides the first evidence in a randomized controlled trial that the 6-step technique is superior, thus these international guidance documents should consider this evidence, as should healthcare organizations using the 3-step technique in practice.

Infect Control Hosp Epidemiol 2016;37:661–666

Impact of Finger Rings on Transmission of Bacteria During Hand Contact

Objective.

To investigate the impact of finger rings on the transmission of bacteria from the hands of healthcare workers and the impact on the microflora on the hands of healthcare workers in clinical practice.

Design.

Our study had a nonequivalent control group posttest-only design (pre-experimental). Healthcare workers who wore finger ring(s) on 1 hand and no ring on the other hand (n = 100) and a control group of healthcare workers who did not wear any rings (n = 100) exchanged standardized hand shakes with an investigator wearing sterile gloves. Samples from the gloved hands of the investigators and the bare hands of the healthcare workers were thereafter obtained by the glove juice technique.

Setting.

Two Norwegian acute care hospitals.

Participants.

Healthcare workers (n = 200) during ordinary clinical work.

Results.

A significantly higher bacterial load (odds ratio, 2.63 [95% confidence interval, 1.28-5.43]; P = .009) and a significantly higher number of bacteria transmitted (odds ratio, 2.43 [95% confidence interval, 1.44-4.13]; P = .001) were associated with ringed hands, compared with control hands. However, a multiple analysis of covariance revealed no statistically significant effect of rings alone. The prevalence of nonfermentative gram-negative bacteria (42% vs 26%) and Enterobacteriaceae (26% vs 13%) was also significantly higher among persons who wore rings than among persons who did not wear rings. However, no statistically significant differences in the incidence of transmission of these pathogens were detected after hand contact. The prevalence of Staphylococcus aureus and incidence of transmission of S. aureus were the same in both groups.

Conclusions.

Wearing finger rings increases the carriage rate of nonfermentative gram-negative bacteria and Enterobacteriaceae on the hands of healthcare workers. However, no statistically significant differences in the incidence of transmission of nonfermentative gram-negative bacteria or Enterobacteriaceae were detected between the healthcare workers who wore rings and those who did not.

Effectiveness of three surgical alcohol-based hand rubs on skin flora

BACKGROUND

It is proved that surgical hand disinfectant contains alcohol, and has favorable properties such as strong and rapid antibacterial effect, ease of application, and suitable effect on skin. Therefore, nowadays use of them has been gradually replacing traditional surgical hand scrub with antibacterial soap. Hence, several domestic and imported products are available to the healthcare facilities in Iran. This study was done in order to determine the antibacterial effect of Decosept, Sterillium, and Septicidine on skin flora.

MATERIALS AND METHODS

This clinical trial was carried out on 20 volunteers. Subjects disinfected their hands with three test products. At first, subjects washed their hands with soap. Then pre-value sample was taken from the finger tips in Tryptic Soy Broth (TSB). After that, the hands were disinfected with one of the surgical hand rubs with as much volume as necessary to keep the hands wet, at the recommended application time. Immediate post-value sample was taken from one hand and the other hand was gloved for 3 h. After removing the surgical glove, 3 h post-value sample (sustained effect) was taken from the hand.

RESULTS

All products remarkably decreased the colony forming units (CFU) immediately (P < 0.0001) and 3 h (P < 0.0001) after disinfection. Analysis of variance (ANOVA) revealed significant differences among immediate post-values (P < 0.005). Septicidine was significantly the least effective than the others, whereas 3 h effect of the three products was similar (P = 0.630, ANOVA).

CONCLUSIONS

Our results confirm the effectiveness of the three alcohol-based hand rubs. Considering the short application time, less volume used, and more antibacterial effect, however, Sterillium seems to be a better choice.

Microbiological analysis of environmental samples collected from child care facilities in North and South Carolina

BACKGROUND

Children cared for outside the home are at an increased risk of enteric disease. Microbiological analyses were performed on environmental samples collected from child care facilities in North and South Carolina.

METHODS

There were 326 samples collected from 40 facilities corresponding to common surfaces (77% of samples) and the hands of care providers (23% of samples). Samples were analyzed for total aerobic plate counts (APCs), total coliforms, biotype I Escherichia coli, and pathogens Shigella spp, Salmonella enterica, E coli O157, Campylobacter jejuni, and human norovirus.

RESULTS

Median APCs and coliform counts for hands were 4.6 and 1.0 log10 colony-forming units (CFU) per hand, respectively. Median APCs for surfaces were 2.0 and 2.6 log10 CFU for flat and irregular surfaces, respectively. Coliforms were detected in 16% of samples, with counts ranging from 1.0 log10 to > 4.3 log10 CFU, with higher counts most often observed for hand rinse samples. Biotype I E coli counts were below assay detection limits (< 1 log10 CFU) for all but 1 sample. No samples were positive for any of the 4 bacterial pathogens, whereas 4 samples showed evidence of human norovirus RNA.

CONCLUSION

The relative absence of pathogens and biotype I E coli in environmental samples suggests the child care facilities sampled in this study managed fecal contamination well.

New method for assessing hand disinfection shows that pre-operative alcohol/chlorhexidine rub is as effective as a traditional surgical scrub

BACKGROUND

Several studies have shown that rubbing hands with an alcohol/chlorhexidine solution provides equivalent microbial decontamination to a conventional surgical scrub using aqueous chlorhexidine. However, the authors believe that these studies have methodological flaws that limit their applicability to the operating theatre environment. As such, a method was developed to compare products in an everyday operating theatre environment using working operating theatre personnel.

AIM

To determine whether or not an alcohol/chlorhexidine rub is as efficacious as a traditional surgical scrub using a novel method.

METHODS

Bacterial counts at baseline were collected from 20 anaesthetists using the glove juice method. Subsequently, with sequential exchange of sterile gloves, one hand underwent a 3-min scrub using 4% aqueous chlorhexidine, and the other hand underwent a 60-s rub with a 70% isopropyl alcohol/0.5% chlorhexidine solution. The residual bacterial count was collected for each hand after 30 min using the glove juice method. These counts were converted to log10 values to compare the baseline counts of right and left hands, and efficacy between the treatment groups.

FINDINGS

Mean [± standard deviation (SD)] bacterial counts at baseline were (log10) 4.42 ± 0.81 for left hands and 4.64 ± 0.60 for right hands (P > 0.05). The mean (± SD) reduction from baseline was (log10) 1.45 ± 0.50 for 4% chlorhexidine and 2.01 ± 0.98 for alcohol/chlorhexidine (P > 0.05).

CONCLUSION

An alcohol/chlorhexidine hand rub was found to be as efficacious as a traditional scrub after 30 min; this study differs from previous work as it was undertaken in a population of practising anaesthetists in their working environment. The McKenzie method allows baseline and study evaluations to be performed contemporaneously on the same individual. Each subject was his/her own control. This method offers a more clinically relevant way to compare disinfectant solutions than standard methods.

Hygienic conditions in child-care facilities in North Carolina and South Carolina: an integrated microbial and observational study

BACKGROUND

In the United States almost one-quarter (23%) of children younger than age 5 years participate in some form of out-of-home child care; these children are 2.3-3.5 times more likely to contract acute gastrointestinal illness.

METHODS

Observational investigations were done to understand the hygienic conditions and practices of 40 child-care facilities in North Carolina and South Carolina. These data were compared with microbiological indicator data (aerobic plate counts and coliform counts) collected from selected surfaces in each facility. Results from the two data sets were analyzed using nonparametric statistical methods to reveal potential risk factors for enteric disease transmission.

RESULTS

Statistically significant differences (P ≤ .05) in surface microbial counts were observed when comparing family child-care homes versus centers and between facilities participating in the Child and Adult Care Food Program and those that do not participate. Facilities without written surface cleaning or food preparation policies had statistically significantly higher microbial counts on surfaces.

CONCLUSIONS

Our unique study, which combined observational and microbiological data, provided revealing information about the relationship between hygiene indicators and sanitary practices in child-care facilities in the southeastern United States.

A quantitative assessment method for Ascaris eggs on hands

The importance of hands in the transmission of soil transmitted helminths, especially Ascaris and Trichuris infections, is under-researched. This is partly because of the absence of a reliable method to quantify the number of eggs on hands. Therefore, the aim of this study was to develop a method to assess the number of Ascaris eggs on hands and determine the egg recovery rate of the method. Under laboratory conditions, hands were seeded with a known number of Ascaris eggs, air dried and washed in a plastic bag retaining the washing water, in order to determine recovery rates of eggs for four different detergents (cationic [benzethonium chloride 0.1% and cetylpyridinium chloride CPC 0.1%], anionic [7X 1% - quadrafos, glycol ether, and dioctyl sulfoccinate sodium salt] and non-ionic [Tween80 0.1% -polyethylene glycol sorbitan monooleate]) and two egg detection methods (McMaster technique and FLOTAC). A modified concentration McMaster technique showed the highest egg recovery rate from bags. Two of the four diluted detergents (benzethonium chloride 0.1% and 7X 1%) also showed a higher egg recovery rate and were then compared with de-ionized water for recovery of helminth eggs from hands. The highest recovery rate (95.6%) was achieved with a hand rinse performed with 7X 1%. Washing hands with de-ionized water resulted in an egg recovery rate of 82.7%. This washing method performed with a low concentration of detergent offers potential for quantitative investigation of contamination of hands with Ascaris eggs and of their role in human infection. Follow-up studies are needed that validate the hand washing method under field conditions, e.g. including people of different age, lower levels of contamination and various levels of hand cleanliness.

Efficacy of surgical hand scrub products based on chlorhexidine is largely overestimated without neutralizing agents in the sampling fluid

BACKGROUND

Surgical hand antiseptics often contain chlorhexidine gluconate (CHG). There are doubts that the full effect measured for these products might only be achieved after sampling because of a lack of valid neutralizing agents (NAs) in the sampling fluid.

METHODS

We measured the efficacy of Avagard CHG and Hibiclens for 11 applications over 5 days according to the manufacturers' instructions. NAs were added to the sampling fluid and the dilution fluid (group 1) or to only the dilution fluid (group 2). In a third group, NAs were added to the dilution fluid only, and cream was applied after the final scrub on days 1 to 4. Neutralization was validated according to American Society for Testing and Materials International standard 1054 using Staphylococcus epidermidis.

RESULTS

When NAs were not added to the sampling fluid, both products were very effective, with a mean log(10) reduction in flora of 3.32 ± 0.53 for Avagard and 3.68 ± 0.52 for Hibiclens on day 5. When NAs were included in the sampling fluid, however, the immediate efficacy was significantly lower, at 2.75 ± 0.55 and 3.14 ± 0.50, respectively. A lack of NAs in the sampling fluid resulted in overestimation of efficacy by a factor of between 0.3 and 1.1 log(10).

CONCLUSION

Efficacy studies carried out without NAs in the sampling fluid for products with CHG should be critically assessed.

Evaluation with a focus on both the antimicrobial efficacy and cumulative skin irritation potential of chlorhexidine gluconate alcohol-containing preoperative skin preparations

BACKGROUND

Important characteristics for ideal skin preparations include long-lasting antimicrobial efficacy and low potential for skin irritation.

METHODS

A total of 55 healthy adult subjects were enrolled to evaluate the antimicrobial effects of 3 test formulations applied to inguinal, abdominal, and antecubital sites at post-treatment time points of 30 seconds, 72 hours, and 7 days. To investigate skin irritation potential, the 3 formulations were tested in a 21-day repeat-insult patch test conducted on the skin of the backs of 23 healthy subjects.

RESULTS

The mean log(10) reduction (MLR) at 7 days post-treatment produced by a 79% vol/vol ethanol containing 1% wt/vol chlorhexidine gluconate (1% CHG-EtOH) applied to abdominal sites was significantly superior to that produced by a 10% povidone-iodine solution (2.45 MLR vs 0.90 MLR; P < .05). The 1% CHG-EtOH and a 70% vol/vol isopropanol containing 2% wt/vol CHG (2% CHG-IPA) provided statistically equivalent persistence at 72 hours and 7 days post-treatment. The 1% CHG-EtOH had less skin irritation potential than the 2% CHG-IPA and the 10% povidone-iodine solution, although the differences were not statistically significant (P > .05).

CONCLUSION

Considering its persistent effect and low skin irritation potential, the 1% CHG-EtOH preparation is expected to perform well in surgical site preparation to reduce the risk of surgery- and catheter-related bloodstream infection.

A comparative clinical study focusing on the antimicrobial efficacies of chlorhexidine gluconate alcohol for patient skin preparations

Comparative efficacy study data showed that skin preparations formulated with more than 0.5% chlorhexidine gluconate (CHG) in alcohol produced significant reductions in microbial populations at the inguinal, abdominal, and antecubital sites at each sample time (P < .05) relative to baseline, and there were no significant differences statistically, including persistent effects within 24 hours (P > .05). It would be reasonable to expect that a 1% CHG-ethanol skin preparation (with >0.5% CHG in alcohol) could be chosen in Japan that would perform well and have promising potential for catheter preparation/maintenance preparation with consideration for recommendation of the Centers for Disease Control and Prevention's guideline issued in 2011.

World Health Organization-recommended hand-rub formulations do not meet European efficacy requirements for surgical hand disinfection in five minutes

The World Health Organization (WHO) has recommended two hand-rub formulations for local production based on 80% ethanol or 75% isopropanol (both v/v). We have looked at their efficacy according to EN 12791. Twenty-six subjects treated their hands with the reference procedure (n-propanol, 60%) for 3 min or with one of the two formulations for 1.5, 3 or 5 min (Latin square design). Post-values (immediate effect) were taken from one hand, the other hand was gloved for 3 h. After the glove had been taken off, the second post-value was taken (3 h effect). The mean log(10) reduction of each hand rub at all three application times was compared to Hodges and Lehmann's reference procedure for non-inferiority. In the first block the reference procedure reduced bacterial load by 2.43 log(10) (immediate effect) and 2.22 log(10) (3 h effect). The efficacy of the ethanol-based formulation (e.g. immediate efficacy of 1.41 log(10) at 5 min) was inferior to the reference procedure at all application times [lower 95% confidence interval (CI): less than -0.75]. In the second block the reference procedure reduced bacterial load by 2.72 log(10) (immediate effect) and 2.26 log(10) (3 h effect). The efficacy of the isopropanol-based formulation (e.g. immediate efficacy of 2.05 log(10) at 5 min) was also inferior to the reference procedure at all application times (lower 95% CI: less than -0.75). Both WHO-recommended hand-rub formulations failed to meet the EN 12791 efficacy requirements for surgical hand disinfection within 5 min. A higher concentration of the active ingredients may improve the efficacy.

Effects of 'bare below the elbows' policy on hand contamination of 92 hospital doctors in a district general hospital

Despite a lack of evidence the UK's Department of Health introduced a policy of 'bare below the elbows' attire in order to try to reduce the incidence of nosocomial infection. This study investigates the link between this state of dress and hand contamination. A prospective observational study of doctors working in a district general hospital was carried out. The fingertips of each hand were imprinted onto culture medium, and resultant growth assessed for number of colony-forming units and presence of clinically significant pathogens or multiply resistant organisms. These findings were correlated with attire, grade, sex and specialty. Ninety-two doctors were recruited of whom 49 were 'bare below the elbows' compliant and 43 were not. There was no statistically significant difference between those doctors who were 'bare below the elbows' and those that were not, either for the number of colony-forming units or for the presence of clinically significant organisms. No multiply resistant organisms were cultured from doctors' hands. 'Bare below the elbows' attire is not related to the degree of contamination on doctors' fingertips or the presence of clinically significant pathogens. Further studies are required to establish whether investment in doctors' uniforms and patient education campaigns are worthwhile.

Improving adherence to surgical hand preparation

At present, no universal agreement on detailed practice for surgical hand preparation exists. In order to fill this gap, in 2002 a Franco-German recommendation for surgical hand preparation was published as a first step towards a generally accepted European recommendation. Based on an assessment of the actual literature, a protocol for surgical hand preparation is discussed with the aim to recommend evidence-based standard procedures including prerequisites, washing and disinfection phase, and its practical implementation. In contrast to hygienic hand disinfection, for surgical hand preparation compliance is not an issue, since it mostly is regarded as a ceremony which is carried out without exception. Nevertheless, the following factors influence acceptance and efficacy: skin tolerance, ease of use, duration of procedure, and recommended time), potential for impaired efficacy due to incorrect performance of the procedure, possibility of systemic risks and irritating potential by applied preparations, religious restrictions, ecological aspects, costs and safety. Here, we report our experience with the introduction of a new hand preparation regime in all surgical disciplines in our university hospital based on the above factors. The following statements were evaluated: 1) The immediate efficacy of an alcohol-based hand disinfectant is impaired by a preceding hand wash for up to 10 minutes. Therefore hands should not be routinely washed before the disinfection period unless there is a good reason for it such as visible soiling. 2) A shortened application time (1.5 minutes) is equal to 3 min in terms of efficacy. 3) Hands should be air dried before gloves are put on, otherwise the perforation rate of gloves will increase. 4) The efficacy of alcohol-based disinfectants is significantly higher when hands are allowed to dry for 1 minute after the washing phase and before the disinfection phase. To clarify the above questions before the establishment of the modified technique, the surgical team was invited to a meeting. As a result, the heads of surgical departments supported the new technique and decided to change their practice.

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.

Pitfalls in efficacy testing--how important is the validation of neutralization of chlorhexidine digluconate?

Background

Effective neutralization of active agents is essential to obtain valid efficacy results, especially when non-volatile active agents like chlorhexidine digluconate (CHG) are tested. The aim of this study was to determine an effective and non-toxic neutralizing mixture for a propan-1-ol solution containing 2% CHG.

Methods

Experiments were carried out according to ASTM E 1054-02. The neutralization capacity was tested separately with five challenge microorganisms in suspension, and with a rayon swab carrier. Either 0.5 mL of the antiseptic solution (suspension test) or a saturated swab with the antiseptic solution (carrier test) was added to tryptic soy broth containing neutralizing agents. After the samples were mixed, aliquots were spread immediately and after 3 h of storage at 2 – 8°C onto tryptic soy agar containing a neutralizing mixture.

Results

The neutralizer was, however, not consistently effective in the suspension test. Immediate spread yielded a valid neutralization with Staphylococcus aureus, Staphylococcus epidermidis and Corynebacterium jeikeium but not with Micrococcus luteus (p < 0.001) and Candida albicans (p < 0.001). A 3-h storage period of the neutralized active agents in suspension resulted in significant carry-over activity of CHG in addition against Staphylococcus epidermidis (p < 0.001) and Corynebacterium jeikeium (p = 0.044). In the carrier test, the neutralizing mixture was found to be effective and non toxic to all challenge microorganisms when spread immediately. However, after 3 h storage of the neutralized active agents significant carry-over activity of CHG against Micrococcus luteus (p = 0.004; Tukey HSD) was observed.

Conclusion

Without effective neutralization in the sampling fluid, non-volatile active ingredients will continue to reduce the number of surviving microorganisms after antiseptic treatment even if the sampling fluid is kept cold straight after testing. This can result in false-positive antiseptic efficacy data. Attention should be paid during the neutralization validation process to the amount of antiseptic solution, the storage time and to the choice of appropriate and sensitive microorganisms.

Quantity of ethanol absorption after excessive hand disinfection using three commercially available hand rubs is minimal and below toxic levels for humans

Background

Despite the increasing promotion of alcohol-based hand rubs and the worldwide use of ethanol-based hand rubs in hospitals only few studies have specifically addressed the issue of ethanol absorption when repeatedly applied to human skin. The aim of this study was to assess if ethanol absorption occurs during hygienic and surgical hand disinfection using three different alcohol-based hand-rubs, and to quantify absorption levels in humans.

Methods

Twelve volunteers applied three hand-rubs containing 95% (hand-rub A), 85% (hand-rub B) and 55% ethanol (hand-rub C; all w/w). For hygienic hand disinfection, 4 mL were applied 20 times for 30 s, with 1 minute break between applications. For surgical hand disinfection, 20 mL of each hand rub was applied to hands and arms up to the level of the elbow 10 times for 3 minutes, with a break of 5 minutes between applications. Blood concentrations of ethanol and acetaldehyde were determined immediately prior and up to 90 minutes after application using head space gas chromatography.

Results

The median of absorbed ethanol after hygienic hand disinfection was 1365 mg (A), 630 mg (B), and 358 mg (C). The proportion of absorbed ethanol was 2.3% (A), 1.1% (B), and 0.9% (C). After surgical hand disinfection, the median of absorbed ethanol was 1067 mg (A), 1542 mg (B), and 477 mg (C). The proportion of absorbed ethanol was 0.7% (A), 1.1% (B), and 0.5% (C). The highest median acetaldehyde concentration after 20 hygienic hand disinfections was 0.57 mg/L (hand-rub C, after 30 min), after 10 surgical hand disinfections 3.99 mg/L (hand-rub A, after 20 minutes).

Conclusion

The overall dermal and pulmonary absorption of ethanol was below toxic levels in humans and allows the conclusion that the use of the evaluated ethanol-based hand-rubs is safe.

Efficacy of two ethanol-based skin antiseptics on the forehead at shorter application times

Background

Recent research suggests that alcohol-based skin antiseptics exhibit their efficacy on the resident skin flora of the forehead in less than 10 minutes. That is why we have looked at the efficacy of two ethanol-based skin antiseptics applied for 10, 2.5 and 2 minutes on skin with a high density of sebaceous glands. Each experiment was performed in a reference-controlled cross-over design with at least 20 participants. Application of isopropanol (70%, v/v) for 10 minutes to the forehead served as the reference treatment. The clear (skin antiseptic A) and coloured preparations (skin antiseptic B) contain 85% ethanol (w/w). Pre-values and post-values (immediately after the application and after 30 min) were obtained by swabbing a marked area of 5 cm² for about 10 s. Swabs were vortexed in tryptic soy broth containing valid neutralizing agents. After serial dilution aliquots were spread on tryptic soy agar. Colonies were counted after incubation of plates at 36°C for 48 h. The mean log₁₀ reduction of bacteria was calculated. The Wilcoxon matched-pairs signed-ranks test was used for a comparison of treatments.

Results

Skin antiseptic A applied for 10 min was significantly more effective than the reference treatment. When applied for 2.5 min (three experiments) it was significantly more effective than the reference treatment immediately after application (2.7 versus 2.2 log₁₀ reduction; p < 0.001) and equally effective after 30 min (2.8 versus 2.6 log₁₀ reduction; p = 0.053). Skin antiseptic B applied for 2.5 min (three experiments) was significantly more effective than the reference treatment both immediately after application (2.3 versus 1.9 log₁₀ reduction; p < 0.001) and after 30 min (2.5 versus 2.1 log₁₀ reduction; p = 0.002).

Conclusion

The clear and coloured skin antiseptics applied for 2.5 min on the skin of the forehead fulfilled the efficacy requirements for skin antisepsis. The shorter application time on skin with a high density of sebaceous glands will allow to act more efficiently in clinical practice.

Does a preceding hand wash and drying time after surgical hand disinfection influence the efficacy of a propanol-based hand rub?

Background

Recently, a propanol-based hand rub has been described to exceed the efficacy requirements of the European standard EN 12791 in only 1.5 min significantly. But the effect of a 1 min preceding hand wash and the effect of one additional minute for evaporation of the alcohol after its application on the efficacy after a 1.5 min application time has never been studied.

Methods

We have investigated a propanol-based hand rub (Sterillium^®, based on 45% propan-2-ol, 30% propan-1-ol and 0.2% mecetronium etilsulfate) in three variations: with (A) and without (B) a 1 min hand wash before the disinfection of 1.5 min with immediate sampling after the disinfection; and (C) without a hand wash before the disinfection but with sampling 1 min after the disinfection. The efficacy of the three variations was compared to the reference treatment of EN 12791. All experiments were performed in a Latin-square design with 20 volunteers. Pre- and post-values (immediate and after 3 hr) were obtained according to EN 12791.

Results

The 3 min reference disinfection reduced resident hand bacteria on average by 1.8 log₁₀ steps (immediate effect) and 1.4 log₁₀-steps (sustained effect) respectively. Method A was equally effective as the reference (immediate efficacy: 1.5 log₁₀-steps; sustained efficacy: 1.6 log₁₀-steps). Method B seemed to be more effective (immediate efficacy: 2.3 log₁₀-steps; sustained efficacy: 1.7 log₁₀-steps). Method C revealed the best efficacy (immediate efficacy: 2.3 log₁₀-steps; sustained efficacy: 2.0 log₁₀-steps). A comparison of all three treatment variations and the reference treatment revealed a significant difference for the immediate efficacy (p = 0.026; Friedman test), but not for the sustained efficacy (p = 0.430). A post-hoc-test for the immediate efficacy indicated a significant difference between methods A and C (p < 0.05; Wilcoxon-Wilcox test). Hence, none of the treatment variations was significantly less effective than the reference treatment.

Conclusion

An application of the propanol-based hand rub for 1.5 min after 1 min hand wash fulfills the efficacy requirements of EN 12791. The efficacy can be improved to some extent by omitting the preceding hand wash and by awaiting the evaporation of the alcohol which is clinical practice anyway. The preceding hand wash has the most negative effect on the immediate effect. Based on our data hands should not be routinely washed before the disinfection period unless there is a good reason for it such as visible soiling.