How effective are hand antiseptics for the postcontamination treatment of hands when used as recommended?

Rinse, gel, and foam - is there any evidence for a difference in their effectiveness in preventing infections?

BACKGROUND

Following publication of the 2009 World Health Organizations Guidelines for Hand Hygiene in Health Care, a debate has emerged regarding the relative antimicrobial efficacy of the different formats (rinse, gel, foam) of ABHRs and their ability to contribute to reduction of healthcare-associated infections (HAIs).

METHODS

Data regarding the in-vivo antimicrobial efficacy of ABHRs and other factors that likely affect their effectiveness in reducing HAIs were reviewed, and a comprehensive review of studies that reported the effectiveness of each of the three ABHR formats to improve hand hygiene compliance and reduce HAIs was conducted.

RESULTS

The amount of rubbing time it takes for hands to feel dry (dry time) is the major driver of ABHR antimicrobial efficacy. ABHR format is not a major factor, and several studies found that rinse, gel, and foam ABHRs have comparable in-vivo antimicrobial efficacy. Other factors that likely impact the ability of ABHRs to reduce transmission of healthcare-associated pathogens and HAIs include ABHR formulation, the volume applied to hands, aesthetic characteristics, skin tolerance, acceptance by healthcare personnel, and hand hygiene compliance rates. When accompanied by complementary strategies, promoting the use of each of the three ABHR formats has been associated with improvements in hand hygiene compliance rates. A review of 67 studies failed to identify an ABHR format that was significantly more effective in yielding statistically significant reductions in transmission of healthcare-associated pathogens or HAIs.

CONCLUSIONS

Current evidence is insufficient to definitively determine if one ABHR format is more effective in reducing transmission of healthcare-associated pathogens and HAIs. More rigorous studies such as multicenter randomized controlled trials comparing the different formats are needed to establish if one format is significantly more effective in reducing HAIs.

Antibacterial assessment of commercially available hand sanitizers in Pakistan by EN-1500

BACKGROUND

The effectiveness of hand sanitizers marketed to the general population is essential for infection prevention and control. Main theme of the study was that whether the commercially available hand sanitizers meet the WHO recommended standards in terms of efficacy? Current study aims to investigate the efficacy of ten commercially available hand sanitizers.

METHODS

The methodology was based on European Standard EN-1500. Following the artificial contamination of hands, pre and post samples were obtained to determine the log reduction values for each sanitizer.

RESULTS

The results showed that out of ten only one sanitizer showed highest log reduction which was comparable to the reference product. Product B was most efficient in sanitization of hands with mean log reduction of 6.00 ± 0.15. The lowest sanitization efficacy was recorded for product F with mean log reduction of 2.40 ± 0.51, however the reference product 2-propanol result in mean log reduction of 6.0 ± 0.00. The products used in this study show a statistical significant results (p value: < 0.01).

CONCLUSION

It is concluded that only one product showed active sanitizer efficacy. This study provides an important insight for manufacturing company and authorizing authorities to assess the efficacy of hand sanitizer. Hand sanitization is one approach to stop the spread of diseases carried on by harmful bacteria inhabiting our hands. Apart from the manufacturing strategies, ensuring proper use and quantity of hand sanitizers is very important.

Effect of Long-Term Use of Alcohol-Containing Handwashing Gels on the Biofilm-Forming Capacity of Staphylococcus epidermidis

The spread of coronavirus disease 2019 (COVID-19) has promoted the use of hand sanitizers among the general population as recommended by health authorities. Alcohols, which are used in many hand sanitizers, have been shown to promotes the formation of biofilms by certain bacteria and to increase bacterial resistance to disinfection. We investigated the effect of continued use of alcohol-based gel hand sanitizer on biofilm formation by the Staphylococcus epidermidis resident strain isolated from the hands of health science students. Hand microbes were counted before and after handwashing, and the ability to produce biofilms was investigated. We found that 179 (84.8%) strains of S. epidermidis isolated from hands had the ability to form biofilm (biofilm-positive strains) in an alcohol-free culture medium. Furthermore, the presence of alcohol in the culture medium induced biofilm formation in 13 (40.6%) of the biofilm-negative strains and increased biofilm production in 111 (76.6%) strains, which were classified as low-grade biofilm-producing. Based on our findings, there is no clear evidence that the continued use of alcohol-based gels results in the selection of strains with the capacity to form biofilms. However, other disinfectant formulations that are more commonly used in clinical settings, such as alcohol-based hand-rub solutions, should be tested for their long-term effects.

Systematic review on factors influencing the effectiveness of alcohol-based hand rubbing in healthcare

Background

The effectiveness of hand rubbing with alcohol-based handrub (ABHR) is impacted by several factors. To investigate these, World Health Organization (WHO) commissioned a systematic review.

Aim

To evaluate the impact of ABHR volume, application time, rubbing friction and hand size on microbiological load reduction, hand surface coverage or drying time.

Methods

Medline, CINAHL, Web of Science and ScienceDirect databases were searched for healthcare or laboratory-based primary studies, published in English, (1980- February 2021), investigating the impact of ABHR volume, application time, rubbing friction or hand size on bacterial load reduction, hand coverage or drying time. Two reviewers independently performed data extraction and quality assessment. The results are presented narratively.

Findings

Twenty studies were included in the review. Categories included: ABHR volume, application time and rubbing friction. Sub-categories: bacterial load reduction, hand size, drying time or hand surface coverage. All used experimental or quasi-experimental designs. Findings showed as ABHR volume increased, bacterial load reduced, and drying times increased. Furthermore, one study showed that the application of sprayed ABHR without hand rubbing resulted in significantly lower bacterial load reduction than poured or sprayed ABHR with hand rubbing (− 0.70; 95%CI: − 1.13 to − 0.28). Evidence was heterogeneous in application time, volume, technique, and product. All studies were assessed as high risk of bias.

Conclusions

There is insufficient evidence to change WHO recommendation of a palmful of ABHR in a cupped hand applied for 20–30 s or manufacturer-recommended volume applied for about 20 s (Centers for Disease Control and Prevention). Future hand hygiene research should standardise volume, application time, and consider hand size.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-021-01049-9.

Consumption of alcohol-based hand rub in French nursing homes: results from a nationwide survey, 2018-2019

This study assessed the hand hygiene performance in French nursing homes using the consumption of alcohol-based hand rubs (AHRs) as a surrogate. Nursing homes from the 17 French regions were contacted to collect their AHR consumption and occupancy in 2018 and 2019. A total of 1290 nursing homes from 15 French regions participated in the survey. The estimated median number of hand hygiene actions per resident-day was 1.48 (interquartile range: 1.04-2.03) in 2018 and 1.60 (1.10-2.26) in 2019. A significantly higher AHR consumption was observed in public nursing homes with an infection control team or link nurse.

Hydrogels in Hand Sanitizers

Hand hygiene can be considered a strategic key useful in the containment of infections such as COVID-19 both at home and in communities because it can dramatically reduce the widespread outbreak of infections. In case of the unavailability of soap and water, "instant" hand sanitizers are recommended because their application can be considered easy, versatile, quick and often less aggressive for the skin. For these reasons, alcoholic and alcohol-free hand rub gels can be considered the best performing formulations on the market. Together with disinfectants and antiseptic agents, hydrogels play a fundamental role in obtaining stable formulations and are easy to disperse, with a pleasant skin feel and an overall good performance. Several compounds commonly used in the pharmaceutical, cosmetic and food industry are available for this purpose, in particular, cellulose derivatives and synthetic polymers derivatives. Each of them is available in several grades, presenting different thickening behavior, rheological properties and compatibility with other ingredients, alcohols in particular. For all these reasons, it is important to explore hydrogel properties and behaviors in different contexts (i.e., hydroalcoholic and aqueous media) in order to develop new and performing hand rub gels, always taking into account the different international legal frameworks regarding disinfectant and sanitizing formulations.

Rinse-free hand wash for reducing absenteeism among preschool and school children

BACKGROUND

Illness-related absenteeism is an important problem among preschool and school children for low-, middle- and high- income countries. Appropriate hand hygiene is one commonly investigated and implemented strategy to reduce the spread of illness and subsequently the number of days spent absent. Most hand hygiene strategies involve washing hands with soap and water, however this is associated with a number of factors that act as a barrier to its use, such as requiring running water, and the need to dry hands after cleaning. An alternative method involves washing hands using rinse-free hand wash. This technique has a number of benefits over traditional hand hygiene strategies and may prove to be beneficial in reducing illness-related absenteeism in preschool and school children.

OBJECTIVES

1. To assess the effectiveness of rinse-free hand washing for reducing absenteeism due to illness in preschool and school children compared to no hand washing, conventional hand washing with soap and water or other hand hygiene strategies. 2. To determine which rinse-free hand washing products are the most effective (if head-to-head comparisons exist), and what effect additional strategies in combination with rinse-free hand washing have on the outcomes of interest.

SEARCH METHODS

In February 2020 we searched CENTRAL, MEDLINE, Embase, CINAHL, 12 other databases and three clinical trial registries. We also reviewed the reference lists of included studies and made direct contact with lead authors of studies to collect additional information as required. No date or language restrictions were applied.

SELECTION CRITERIA

Randomized controlled trials (RCTs), irrespective of publication status, comparing rinse-free hand wash in any form (hand rub, hand sanitizer, gel, foam etc.) with conventional hand washing using soap and water, other hand hygiene programs (such as education alone), or no intervention. The population of interest was children aged between two and 18 years attending preschool (childcare, day care, kindergarten, etc.) or school (primary, secondary, elementary, etc.). Primary outcomes included child or student absenteeism for any reason, absenteeism due to any illness and adverse skin reactions.

DATA COLLECTION AND ANALYSIS

Following standard Cochrane methods, two review authors (out of ZM, CT, CL, CS, TB), independently selected studies for inclusion, assessed risk of bias and extracted relevant data. Absences were extracted as the number of student days absent out of total days. This was sometimes reported with the raw numbers and other times as an incidence rate ratio (IRR), which we also extracted. For adverse event data, we calculated effect sizes as risk ratios (RRs) and present these with 95% confidence intervals (CIs). We used standard methodological procedures expected by Cochrane for data analysis and followed the GRADE approach to establish certainty in the findings.

MAIN RESULTS

This review includes 19 studies with 30,747 participants. Most studies were conducted in the USA (eight studies), two were conducted in Spain, and one each in China, Colombia, Finland, France, Kenya, Bangladesh, New Zealand, Sweden, and Thailand. Six studies were conducted in preschools or day-care centres (children aged from birth to < five years), with the remaining 13 conducted in elementary or primary schools (children aged five to 14 years). The included studies were judged to be at high risk of bias in several domains, most-notably across the domains of performance and detection bias due to the difficulty to blind those delivering the intervention or those assessing the outcome. Additionally, every outcome of interest was graded as low or very low certainty of evidence, primarily due to high risk of bias, as well as imprecision of the effect estimates and inconsistency between pooled data. For the outcome of absenteeism for any reason, the pooled estimate for rinse-free hand washing was an IRR of 0.91 (95% CI 0.82 to 1.01; 2 studies; very low-certainty evidence), which indicates there may be little to no difference between groups. For absenteeism for any illness, the pooled IRR was 0.82 (95% CI 0.69 to 0.97; 6 studies; very low-certainty evidence), which indicates that rinse-free hand washing may reduce absenteeism (13 days absent per 1000) compared to those in the 'no rinse-free' group (16 days absent per 1000). For the outcome of absenteeism for acute respiratory illness, the pooled IRR was 0.79 (95% CI 0.68 to 0.92; 6 studies; very low-certainty evidence), which indicates that rinse-free hand washing may reduce absenteeism (33 days absent per 1000) compared to those in the 'no rinse-free' group (42 days absent per 1000). When evaluating absenteeism for acute gastrointestinal illness, the pooled estimate found an IRR of 0.79 (95% CI 0.73 to 0.85; 4 studies; low-certainty evidence), which indicates rinse-free hand washing may reduce absenteeism (six days absent per 1000) compared to those in the 'no rinse-free' group (eight days absent per 1000). There may be little to no difference between rinse-free hand washing and 'no rinse-free' group regarding adverse skin reactions with a RR of 1.03 (95% CI 0.8 to 1.32; 3 studies, 4365 participants; very low-certainty evidence). Broadly, compliance with the intervention appeared to range from moderate to high compliance (9 studies, 10,749 participants; very-low certainty evidence); narrativley, no authors reported substantial issues with compliance. Overall, most studies that included data on perception reported that teachers and students perceived rinse-free hand wash positively and were willing to continue its use (3 studies, 1229 participants; very-low certainty evidence).

AUTHORS' CONCLUSIONS

The findings of this review may have identified a small yet potentially beneficial effect of rinse-free hand washing regimes on illness-related absenteeism. However, the certainty of the evidence that contributed to this conclusion was low or very low according to the GRADE approach and is therefore uncertain. Further research is required at all levels of schooling to evaluate rinse-free hand washing regimens in order to provide more conclusive, higher-certainty evidence regarding its impact. When considering the use of a rinse-free hand washing program in a local setting, there needs to be consideration of the current rates of illness-related absenteeism and whether the small beneficial effects seen here will translate into a meaningful reduction across their settings.

Demonstrating the persistent antibacterial efficacy of a hand sanitizer containing benzalkonium chloride on human skin at 1, 2, and 4 hours after application

BACKGROUND

Use of hand sanitizers has become a cornerstone in clinical practice for the prevention of disease transmission between practitioners and patients. Traditionally, these preparations have relied on ethanol (60%-70%) for bactericidal action.

METHODS

This study was conducted to measure the persistence of antibacterial activity of 2 preparations. One was a non-alcohol-based formulation using benzalkonium chloride (BK) (0.12%) and the other was an ethanol-based formulation (63%) (comparator product). The persistence of antibacterial activity was measured against Staphylococcus aureus using a technique modification prescribed in American Society for Testing and Materials protocol E2752-10 at up to 4 hours after application.

RESULTS

The test product (BK) produced a marked reduction in colony-forming units at each of the 3 time points tested (3.75-4.16-log₁₀ reductions), whereas the comparator produced less than 1-log₁₀ reduction over the same time. The differences were highly significant.

DISCUSSION

In the course of patient care or examination, there are instances where opportunities exist for the practitioner's hands to become contaminated (eg, key boards and tables). Persistent antibacterial activity would reduce the chances of transfer to the patient.

CONCLUSIONS

These results show a major improvement in persistent antibacterial activity for the BK formulation compared to the comparator ethanol-based formulation.

Current issues in hand hygiene

Although substantial improvements in hand hygiene practices have occurred in recent years, many health care facilities continue to encounter challenges in achieving and maintaining high levels of hand hygiene compliance. Issues of current interest include the optimum dose of alcohol-based handrub (ABHR) that should be applied, the impact of hand size and alcohol-based handrub dry times have on efficacy, and ideal hand hygiene technique. There is a need to determine which additional promotional activities can augment improvements in hand hygiene that are achieved by implementing the multimodal improvement strategy recommended by the World Health Organization. Monitoring hand hygiene performance and providing personnel with feedback on their performance are essential elements of successful improvement programs. Further research is needed to establish the most effective methods of providing feedback. Additional studies are needed to optimize strategies for performing direct observation of hand hygiene compliance, and to determine the role of supplementing direct observations using automated monitoring systems.

Desiccation and ethanol resistances of multidrug resistant Acinetobacter baumannii embedded in biofilm: The favorable antiseptic efficacy of combination chlorhexidine gluconate and ethanol

BACKGROUND/PURPOSE

Globally, multidrug-resistant Acinetobacter baumannii (MDRAB) has emerged as an important pathogen in nosocomial outbreaks. This study aimed to investigate the correlation between the biofilm formation and survival of MDRABs, and to investigate the antiseptic efficacy of hand sanitizers for the MDRABs, embedded with biofilm (MDRAB-Bs).

METHODS

The MDRABs were selected randomly after pulsed-field gel electrophoresis (PFGE), and their biofilm formation was analyzed. Desiccation and ethanol tolerances were assayed to test the bacterial survival. The antiseptic efficacy of combined chlorhexidine gluconate (CHG) and 70% ethanol agents against MDRAB-Bs were compared with the 70% ethanol cleanser.

RESULTS

Eleven MDRABs, which varied in biofilm formation (MRDAB-B) and planktonic type (MDRAB-P), were tested. In desiccation survival, the mean survival time for the MDRAB-Bs was 49.0 days which was significantly higher than that of their planktonic type (17.3 days) (P < 0.005). The MDRAB-Ps could be eliminated after a 10 min contact with a 30% ethanol agent, however, it took 10 min of 70% ethanol to eliminate the MDRAB-Bs. On the other hand, a 2% CHG in 70% ethanol solution completely eliminated all MDRAB-Bs after 1 min contacted time. The 2% CHG in 70% ethanol agent provided a significantly superior efficacy than the 70% ethanol solution at eliminating the MDRAB-Bs (P < 0.005).

CONCLUSION

MDRAB with biofilm-formation presented significantly higher desiccation and ethanol resistances than their planktonic type. Moreover, the 2% CHG in 70% ethanol agent provided a superior antiseptic efficacy for MDRAB-Bs than that of the 70% ethanol agent.

Hand Hygiene With Alcohol-Based Hand Rub: How Long Is Long Enough?

BACKGROUND Hand hygiene is the core element of infection prevention and control. The optimal hand-hygiene gesture, however, remains poorly defined. OBJECTIVE We aimed to evaluate the influence of hand-rubbing duration on the reduction of bacterial counts on the hands of healthcare personnel (HCP). METHODS We performed an experimental study based on the European Norm 1500. Hand rubbing was performed for 10, 15, 20, 30, 45, or 60 seconds, according to the WHO technique using 3 mL alcohol-based hand rub. Hand contamination with E. coli ATCC 10536 was followed by hand rubbing and sampling. A generalized linear mixed model with a random effect on the subject adjusted for hand size and gender was used to analyze the reduction in bacterial counts after each hand-rubbing action. In addition, hand-rubbing durations of 15 and 30 seconds were compared to assert non-inferiority (0.6 log10). RESULTS In total, 32 HCP performed 123 trials. All durations of hand rubbing led to significant reductions in bacterial counts (P<.001). Reductions achieved after 10, 15, or 20 seconds of hand rubbing were not significantly different from those obtained after 30 seconds. The mean bacterial reduction after 15 seconds of hand rubbing was 0.11 log10 lower (95% CI, -0.46 to 0.24) than after 30 seconds, demonstrating non-inferiority. CONCLUSIONS Hand rubbing for 15 seconds was not inferior to 30 seconds in reducing bacterial counts on hands under the described experimental conditions. There was no gain in reducing bacterial counts from hand rubbing longer than 30 seconds. Further studies are needed to assess the clinical significance of our findings. Infect Control Hosp Epidemiol 2017;38:547-552.

A multifactorial action plan improves hand hygiene adherence and significantly reduces central line-associated bloodstream infections

BACKGROUND

Although hand hygiene (HH) is key to reducing health care-associated infections, it is well documented that health care worker (HCW) adherence to appropriate HH protocols is relatively low.

METHODS

This was a collaborative quality improvement project with multiple interventions conducted in a 570-bed academic hospital in Columbia, MO between April 2006 and September 2012. A multimodal action plan to improve HH adherence among all HCWs was developed, addressing 4 key areas: staff education, staff accountability, hand sanitizer product selection and accessibility, and organizational culture. HH adherence and central line-associated bloodstream infection (CLABSI) rates were monitored as outcome measures.

RESULTS

The overall HH adherence rate increased from 58% in April 2006 to 98% in September 2012. The adherence rates increased among all hospital units and among all HCW categories; in September 2012, HH adherence was 96% for physicians, 99% for nursing staff, and 99% for food services staff. CLABSI rates decreased over the same period, from 4.08 per 1000 device-days to 0.42 per 1000 device-days.

CONCLUSIONS

This multifactorial quality improvement project resulted in an institution-wide increase in HH adherence and a significant decrease in CLABSIs.

The relative influences of product volume, delivery format and alcohol concentration on dry-time and efficacy of alcohol-based hand rubs

Background

Alcohol-based hand rubs (ABHR) range in alcohol concentration from 60-95% and are available in a variety of delivery formats, such as rinses, gels, and foams. Recent studies suggest that some ABHR foams dry too slowly, thereby encouraging the use of inadequate volumes. This study investigates the influence of product volume, delivery format, and alcohol concentration on dry-time and antimicrobial efficacy of ABHR foams, gels and rinses.

Methods

ABHR dry-times were measured using volunteers to determine the influences of product volume, delivery format, and alcohol concentration. ABHR efficacies were evaluated according to the European Standard for Hygienic Hand Disinfection (EN 1500) using 3-mL application volumes rubbed for 30 s, and additionally, using volumes of the products determined to rub dry in 30 s.

Results

Volumes of six ABHR determined to rub dry in 30 s ranged from 1.7 mL to 2.1 mL, and the rate of drying varied significantly between products. ABHR dry-times increased linearly with application volume and decreased linearly with increasing alcohol concentration, but were not significantly influenced by product format. An ABHR foam (70% EtOH), rinse (80% EtOH), and gel (90% EtOH) each met EN 1500 efficacy requirements when tested at a volume of 3 mL, but failed when tested at volumes that dried in 30 s.

Conclusions

Application volume is the primary driver of ABHR dry-time and efficacy, whereas delivery format does not significantly influence either. Although products with greater alcohol concentration dry more quickly, volumes required to meet EN 1500 can take longer than 30 s to dry, even when alcohol concentration is as high as 90%. Future studies are needed to better understand application volumes actually used by healthcare workers in practice, and to understand the clinical efficacy of ABHR at such volumes.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2334-14-511) contains supplementary material, which is available to authorized users.

Small volumes of n-propanol (60%) applied for 3 minutes may be ineffective for surgical hand disinfection

Background

There is a trend in some countries to recommend the use of surgical hand disinfectants at volumes as low as 4 ml per application.

Aim

To determine whether the volume applied and hand size influence the efficacy of surgical hand disinfection.

Methods

Thirteen experiments, according to EN 12791, resulting in 269 datasets from 75 subjects were analyzed. Hands were first washed for one minute with soap. The pre-values were obtained by rubbing the finger tips in tryptic soy broth for one minute. Each subject treated his/her hands with n-propanol (60%, v/v), with as many portions as necessary to keep the hands wet for three minutes (6–12 ml). Bacterial post-values were taken from one hand (immediate effect); the other hand was gloved for three hours (sizes 7–9). The second post-value was taken when the glove was removed (3 h effect).

Results

The mean immediate log₁₀ reduction of CFU was 2.56 ± 1.12. The glove size had no significant effect on the efficacy of disinfection (p = 0.182; ANOVA). However, a volume of 6 ml was significantly less effective than 9 ml for glove sizes of 7.5–8 (p < 0.05; Tukey post hoc analysis). The mean log₁₀ reduction after 3 h was 2.12 ± 1.24. A volume of 6 ml was again significantly less effective than 12 ml for glove size 7 and than 9 ml for glove sizes 7.5–8 (p < 0.05).

Conclusions

The application of small volumes of surgical hand disinfectant when using the EN 12791 reference procedure is likely to yield poor efficacy results, regardless of hand size.

Changes in hand hygiene compliance after a multimodal intervention and seasonality variation

BACKGROUND

Hand hygiene is the most important measure to reduce health care-related infections and colonization with multiresistant micro-organisms. We sought to determine the rate and seasonality of handwashing compliance in a university-affiliated hospital.

METHODS

In January 2006 (baseline period), handwashing observation was first made in an intensive care unit. From March to May 2006, there was an intervention period; and, from June 2006 to August 2009, we followed hand hygiene compliance. Seasonality curves for handwashing compliance were made during follow-up period.

RESULTS

During baseline period, a total of 166 observations was made. During follow-up, 17,664 opportunities for hand hygiene were observed. Compliance improved from 30.0% to a mean of 56.7% after the intervention (P < .001). The highest mean rate of compliance was 77.9% for nurses, compared with 52.6% for technicians (P < .001) and 44.6% for physicians (P < .001). Compliance was lower during summer days (first trimester of the year) and increased after March and April and slowly decreased through the end of the year.

CONCLUSION

One of the reasons for the lower handwashing compliance in the first 3 months of the year is that, in Brazil, this is the summer vacation time; and, because of that, the staff's workload and the number of less well-trained personnel are higher. We emphasize the importance of continuously monitoring hand hygiene to determine the seasonal aspects of compliance.

Less and less-influence of volume on hand coverage and bactericidal efficacy in hand disinfection

Background

Some manufacturers recommend using 1.1 mL per application of alcohol-based handrubs for effective hand disinfection. However, whether this volume is sufficient to cover both hands, as recommended by the World Health Organization, and fulfills current efficacy standards is unknown. This study aimed to determine hand coverage for three handrubs (two gels based on 70% v/v and 85% w/w ethanol and a foam based on 70% v/v ethanol) applied at various volumes.

Methods

Products were tested at product volumes of 1.1 mL, 2 mL, 2.4 mL as well as 1 and 2 pump dispenser pushes; the foam product was tested in addition at foam volumes of 1.1 mL, 2 mL, and 2.4 mL. Products were supplemented with a fluorescent dye and 15 participants applied products using responsible application techniques without any specific steps but the aim of completely covering both hands. Coverage quality was determined under ultraviolet light by two blinded investigators. Efficacy of the three handrubs was determined according to ASTM E 1174-06 and ASTM E 2755-10. For each experiment, the hands of 12 participants were contaminated with Serratia marcescens and the products applied as recommended (1.1 mL for 70% v/v ethanol products; 2 mL for the 85% w/w ethanol product). Log₁₀-reduction was calculated.

Results

Volumes < 2 mL yielded high rates of incomplete coverage (67%–87%) whereas volumes ≥ 2 mL gave lower rates (13%–53%). Differences in coverage were significant between the five volumes tested for all handrubs (p < 0.001; two-way ANOVA) but not between the three handrubs themselves (p = 0.796). Application of 1.1 mL of 70% v/v ethanol rubs reduced contamination by 1.85 log₁₀ or 1.60 log₁₀ (ASTM E 1174-06); this failed the US FDA efficacy requirement of at least 2 log₁₀. Application of 2 mL of the 85% w/w ethanol rub reduced contamination by 2.06 log₁₀ (ASTM E 1174-06), fulfilling the US FDA efficacy requirement. Similar results were obtained according to ASTM E 2755-10.

Conclusions

Our data indicated that handrubs based on 70% ethanol (v/v) with a recommended volume of 1.1 mL per application do not ensure complete coverage of both hands and do not achieve current ASTM efficacy standards.

[Comparison of antimicrobial effect of alcohol gel according to the amount and drying time in health personnel hand hygiene]

PURPOSE

The purpose of this study was to compare the effect of alcohol gel according to the amount and drying time in health personnel hand hygiene and to promote in their practice adequate and effective hand hygiene.

METHODS

The cross-over experimental study was performed with 14 volunteers. Hands were artificially contaminated with 5 mL of 10⁸ CFU/mL of Serratia marcescens (ATCC 14756) and four different alcohol gel hand hygiene methods varying by the amount of alcohol gel (2 mL vs. 1 mL) and drying time (complete vs. incomplete) were compared. Samples were collected by glove juice sampling procedures.

RESULTS

Mean log reduction values of the four different hand hygiene methods were 2.22±0.36, 1.26±0.53, 1.49±0.60, 0.89±0.47 respectively for the 4 groups: adequate amount (2mL) and complete dry (30 seconds rubbing followed by 2 min air-dry), inadequate amount (1 mL) and complete dry, adequate amount and incomplete dry (15 seconds rubbing and no air-dry), and inadequate amount and incomplete dry. The difference was statistically significant in the adequate amount and complete dry group compared to other three groups (p<.001).

CONCLUSION

Only alcohol gel hand hygiene with adequate amount and complete drying was satisfactory by U.S. FDA-TFM efficacy requirements for antiseptic hand hygiene products.

Comparative efficacy of commercially available alcohol-based hand rubs and World Health Organization-recommended hand rubs: formulation matters

BACKGROUND

Use of alcohol-based hand rubs (ABHRs) effectively reduces transmission of pathogenic microorganisms. However, the impact of alcohol concentration and format on product efficacy is currently being debated.

METHODS

Two novel ABHR formulations containing 70% ethanol were evaluated according to American Society for Testing and Materials E1174 (Health Care Personnel Handwash [HCPHW]) and European Norm (EN) 1500 global standards. Additionally, using E1174, the efficacy of these formulations was compared head-to-head against 7 representative commercially available ABHRs and 2 World Health Organization recommended formulations containing alcohol concentrations of 60% to 90%.

RESULTS

The novel ABHR formulations met efficacy requirements for both HCPHW and EN 1500 when tested at application volumes typically used in these methods. Moreover, these formulations met HCPHW requirements when tested at a more realistic 2-mL product application. In contrast, the commercial ABHRs and World Health Organization formulations failed to meet HCPHW requirements using a 2-mL application. Importantly, product performance did not correlate with alcohol concentration.

CONCLUSION

Product formulation can greatly influence the overall antimicrobial efficacy of ABHRs and is a more important factor than alcohol concentration alone. Two novel ABHRs based on 70% ethanol have been formulated to meet global efficacy standards when tested at volumes more representative of normal product use in health care environments.

Revisiting the hand wipe versus gel rub debate: is a higher-ethanol content hand wipe more effective than an ethanol gel rub?

BACKGROUND

The Centers for Disease Control and Prevention's guidelines for hand hygiene state that the use of alcohol-based hand wipes is not an effective substitute for the use of an alcohol-based hand rub or handwashing with an antimicrobial soap and water. The objective of this study was to determine whether a hand wipe with higher ethanol content (65.9%) is as effective as an ethanol hand rub or antimicrobial soap in removing bacteria and spores from hands.

METHODS

In two separate experiments, the hands of 7 subjects were inoculated with a suspension of Serratia marcescens or Geobacillus stearothermophilus. Subjects washed with each of 3 different products: 65.9% ethanol hand wipes (Sani-Hands ALC), 62% ethanol gel rub (Purell), and antimicrobial soap containing 0.75% triclosan (Kindest Kare).

RESULTS

A total of 56 observations were analyzed for S marcescens removal and 70 observations were analyzed for G stearothermophilus removal. The rank order of product efficacy for both bacteria and spore removal was antibacterial soap > 65.9% ethanol hand wipes >62% ethanol hand rub. Mean S marcescens log reductions (±SD) for the 65.9% ethanol alcohol wipe, 62% ethanol alcohol rub, and antimicrobial foam soap were 3.44 ± 0.847, 2.32 ± 1.065, and 4.44 ± 1.018, respectively (P < .001). Mean G stearothermophilus log reductions for the 65.9% ethanol wipe, 62% ethanol rub, and antimicrobial foam soap were 0.51 ± 0.26, -0.8 ± 0.32 increase over baseline, and 1.72 ± 0.62, respectively (P < .001).

CONCLUSION

The alcohol-based hand wipe containing 65.9% ethanol was significantly more effective than the 62% ethanol rub in reducing the number of viable bacteria and spores on the hands.

Efficacy of ethanol-based hand foams using clinically relevant amounts: a cross-over controlled study among healthy volunteers

BACKGROUND

Foams containing 62% ethanol are used for hand decontamination in many countries. A long drying time may reduce the compliance of healthcare workers in applying the recommended amount of foam. Therefore, we have investigated the correlation between the applied amount and drying time, and the bactericidal efficacy of ethanol foams.

METHODS

In a first part of tests, four foams (Alcare plus, Avagard Foam, Bode test foam, Purell Instant Hand Sanitizer) containing 62% ethanol, which is commonly used in U.S. hospitals, were applied to 14 volunteers in a total of seven variations, to measure drying times. In a second part of tests, the efficacy of the established amount of foam for a 30 s application time of two foams (Alcare plus, Purell Instant Hand Sanitizer) and water was compared to the EN 1500 standard of 2 x 3 mL applications of 2-propanol 60% (v/v), on hands artificially contaminated with Escherichia coli. Each application used a cross-over design against the reference alcohol with 15 volunteers.

RESULTS

The mean weight of the applied foam varied between 1.78 and 3.09 g, and the mean duration to dryness was between 37 s and 103 s. The correlation between the amount of foam applied and time until hands felt dry was highly significant (p < 0.001; Pearson's correlation coefficient: 0.724; 95% confidence interval: 0.52-0.93). By linear correlation, 1.6 g gave an intercept of a 30 s application time. Application of 1.6 g of Purell Instant Hand Sanitizer (mean log10-reduction: 3.05 +/- 0.45) and Alcare plus (3.58 +/- 0.71) was significantly less effective than the reference disinfection (4.83 +/- 0.89 and 4.60 +/- 0.59, respectively; p < 0.001). Application of 1.6 g of water gave a mean log10-reduction of 2.39 +/- 0.57.

CONCLUSIONS

When using 62% ethanol foams, the time required for dryness often exceeds the recommended 30 s. Therefore, only a small volume is likely to be applied in clinical practice. Small amounts, however, failed to meet the efficacy requirements of EN 1500 and were only somewhat more effective than water.

Impact of the amount of hand rub applied in hygienic hand disinfection on the reduction of microbial counts on hands

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

Influence of rub-in technique on required application time and hand coverage in hygienic hand disinfection

BACKGROUND

Recent data indicate that full efficacy of a hand rub preparation for hygienic hand disinfection can be achieved within 15 seconds (s). However, the efficacy test used for the European Norm (EN) 1500 samples only the fingertips. Therefore, we investigated hand coverage using sixteen different application variations. The hand rub was supplemented with a fluorescent dye, and hands were assessed under UV light by a blind test, before and after application. Fifteen non-healthcare workers were used as subjects for each application variation apart from one test which was done with a group of twenty healthcare workers. All tests apart from the reference procedure were performed using 3 mL of hand rub. The EN 1500 reference procedure, which consists of 6 specific rub-in steps performed twice with an aliquot of 3 ml each time, served as a control. In one part of this study, each of the six steps was performed from one to five times before proceeding to the next step. In another part of the study, the entire sequence of six steps was performed from one to five times. Finally, all subjects were instructed to cover both hands completely, irrespective of any specific steps ("responsible application"). Each rub-in technique was evaluated for untreated skin areas.

RESULTS

The reference procedure lasted on average 75 s and resulted in 53% of subjects with at least one untreated area on the hands. Five repetitions of the rub-in steps lasted on average 37 s with 67% of subjects having incompletely treated hands. One repetition lasted on average 17 s, and all subjects had at least one untreated area. Repeating the sequence of steps lasted longer, but did not yield a better result. "Responsible application" was quite fast, lasting 25 s among non-healthcare worker subjects and 28 s among healthcare workers. It was also effective, with 53% and 55% of hands being incompletely treated. New techniques were as fast and effective as "responsible application". Large untreated areas were found only with short applications. Fingertips and palms were often covered completely.

CONCLUSION

In clinical practice, hand disinfection is apparently better than practitioners of infection control often anticipate. Based on our data, a high-quality hygienic hand disinfection is not possible within 15 s. A 30 s application time can, however, be recommended for clinical practice. The currently recommended six steps of EN 1500 are not really suitable for clinical practice, because they yield comparably poor results. The most appropriate application procedure may be "responsible application", or one of the other new techniques.

Comprehensive bactericidal activity of an ethanol-based hand gel in 15 seconds

BACKGROUND

Some studies indicate that the commonly recommended 30 s application time for the post contamination treatment of hands may not be necessary as the same effect may be achieved with some formulations in a shorter application time such as 15 s.

METHOD

We evaluated the bactericidal activity of an ethanol-based hand gel (Sterillium Comfort Gel) within 15 s in a time-kill-test against 11 Gram-positive, 16 Gram-negative bacteria and 11 emerging bacterial pathogens. Each strain was evaluated in quadruplicate.

RESULTS

The hand gel (85% ethanol, w/w) was found to reduce all 11 Gram-positive and all 16 Gram-negative bacteria by more than 5 log10 steps within 15 s, not only against the ATCC test strains but also against corresponding clinical isolates. In addition, a log10 reduction > 5 was observed against all tested emerging bacterial pathogens.

CONCLUSION

The ethanol-based hand gel was found to have a broad spectrum of bactericidal activity in only 15 s which includes the most common species causing nosocomial infections and the relevant emerging pathogens. Future research will hopefully help to find out if a shorter application time for the post contamination treatment of hands provides more benefits or more risks.