The effects of test variables on the efficacy of hand hygiene agents

Long-term effectiveness evaluation of an action-research intervention to improve hand hygiene in an intensive care unit

OBJECTIVES

To evaluate the long-term effectiveness of an action research intervention aimed at improving hand hygiene in an intensive care unit of a public hospital in Italy.

METHODS

An observational, prospective before-after study was carried out.Compliance with hand hygiene was estimated by measuring the utilization of hand hygiene products before the intervention and four years after the end of the project. Products used were the following: detergent liquid soap, antiseptic liquid soap and alcohol-based hand gel. Endpoints were quantity consumed (in grams) for each product category. Quantitative consumptions per workshift were compared.

RESULTS

In 2017 the median consumption of antiseptic liquid soap and alcohol-based hand gel per workshift was significantly higher than in 2012 (111.5 g vs 72.5 g, p = 0.014, and 18.0 g vs 5.0 g, p < 0.001). Odds in favour of a higher value in 2017 were 1.99:1 (CI95%: 1.19:1 to 3.73:1) for antiseptic solution, and 5.39:1 (CI95%: 3.09:1 to 13.61:1) for antiseptic gel. Covariates were not associated with consumption of products, and this made it possible to compare the measurements in the two data collections.

CONCLUSIONS

Results of this study support the long-term effectiveness of the action research intervention to improve practices of hand hygiene in an intensive care setting.

Alcohol-based hand sanitisers as first line of defence against SARS-CoV-2: a review of biology, chemistry and formulations

The pandemic due to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has emerged as a serious global public health issue. Since the start of the outbreak, the importance of hand-hygiene and respiratory protection to prevent the spread of the virus has been the prime focus for infection control. Health regulatory organisations have produced guidelines for the formulation of hand sanitisers to the manufacturing industries. This review summarises the studies on alcohol-based hand sanitisers and their disinfectant activity against SARS-CoV-2 and related viruses. The literature shows that the type and concentration of alcohol, formulation and nature of product, presence of excipients, applied volume, contact time and viral contamination load are critical factors that determine the effectiveness of hand sanitisers.

Antiviral efficacy of personal care formulations against Severe Acute Respiratory Syndrome Coronavirus 2

Background

Non-therapeutic interventions such as practicing good hand hygiene continue to be the mainstay of protection from SARS-CoV-2 and other emerging respiratory viruses.

Methods

We have evaluated a range of commercially available personal care products including soaps, handwash liquids and alcohol-based hand sanitizers for antiviral efficacy against a clinical isolate of SARS-CoV-2 using internationally accepted standardized protocols at user-relevant contact time-points and product dilutions.

Results

All the tested products resulted in 3 to 4 log reduction of SARS-CoV-2 titer.

Conclusion

Our data re-affirms recommendations by global public health authorities that proper hand hygiene can reduce SARS-CoV-2 viral load significantly which should likely limit spread of the contagion.

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Personal care formulations from Unilever showed efficacy against SARS-CoV-2.

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All tests were conducted at user relevant contact duration and product dilution.

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Soap bars with varying TFM content resulted in ≥ 3 log reduction.

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Liquid cleansers with varying surfactant levels resulted in ≥ 3 log reduction.

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Sanitizers with variable % of alcohol resulted in ≥ 3 to 4 log reduction.

Evaluation of the impact of antimicrobial hand towels on hand contamination with Escherichia coli among mothers in Kisumu County, Kenya, 2011-2012

Poor hand hygiene contributes to diarrhea in developing countries. Handwashing with soap reduces diarrhea risk, but drying hands on contaminated towels can compromise the benefits of handwashing. In response to the challenge of keeping hands clean, an antimicrobial hand towel was developed and shown to be promising in the laboratory, but has not been adequately tested in the field. We evaluated the effectiveness of an antimicrobial towel in two randomized, double-blinded crossover trials among mothers with children<5 years old in 125 households in western Kenya. In trial 1, we randomly assigned mothers to use either the treated towel or an identical untreated (placebo) towel and made surprise home visits at random times once a week for three weeks. At each visit, we tested hands for Escherichia coli using sterile hand rinses, then switched towel types in the two groups and repeated three weekly rounds of E. coli testing. In crossover trial 2, we compared E. coli contamination of maternal hands immediately following three different handwashing/drying procedures: soap and water + treated towel, water only + treated towel, and soap and water + air dry. There was no statistically significant difference in the level of E. coli contamination on maternal hands by type of towel used during trial 1 (odds ratio for treated vs untreated towel: 1.14, 95% confidence interval 0.83-1.56). In trial 2, there were no significant differences in E. coli contamination of maternal hands by handwashing/drying procedure. In these trials, use of antimicrobial hand towels did not prevent E. coli contamination of mothers' hands in Kenyan households during random testing and offered no advantages over standard handwashing and drying practices. Handwashing with soap and clean water and drying with clean towels are recommended.

Safely Managed Hygiene: A Risk-Based Assessment of Handwashing Water Quality

Sustainable Development Goal (SDG) Indicator 6.2.1 requires household handwashing facilities to have soap and water, but there are no guidelines for handwashing water quality. In contrast, drinking water quality guidelines are defined: water must be "free from contamination" to be defined as "safely managed" (SDG Indicator 6.1.1). We modeled the hypothesized mechanism of infection due to contaminated handwashing water to inform risk-based guidelines for microbial quality of handwashing water. We defined two scenarios that should not occur: (1) if handwashing caused fecal contamination, indicated using Escherichia coli, on a person's hands to increase rather than decrease and (2) if hand-to-mouth contacts following handwashing caused an infection risk greater than an acceptable threshold. We found water containing <1000 E. coli colony-forming units (CFU) per 100 mL removes E. coli from hands with>99.9% probability. However, for the annual probability of infection to be <1:1000, handwashing water must contain <2 × 10^-6 focus-forming units of rotavirus, <1 × 10^-4 CFU of Vibrio cholerae, and <9 × 10^-6 Cryptosporidium oocysts per 100 mL. Our model suggests that handwashing with nonpotable water will generally reduce fecal contamination on hands but may be unable to lower the annual probability of infection risks from hand-to-mouth contacts below 1:1000.

A bioassay-based protocol for chemical neutralization of human faecal wastes treated by physico-chemical disinfection processes: A case study on benzalkonium chloride

In situ physico-chemical disinfection of high risk faecal waste is both effective and widely used as a sanitation management strategy for infection prevention and control. Systematic tests where the performance of alternative physico-chemical disinfection methods is systematically compared and optimized must be based on reliable protocols. These protocol are currently not adequately addressing the neutralization related issues: the neutralization of the tested disinfectant after specified conditions of concentration and contact time (CT) is necessary to prevent continued disinfection after the intended contact time; moreover such neutralization is often necessary in practice and on a large scale to prevent adverse health and ecological impacts from remaining disinfectant after the target CT is achieved. Few studies adequately assess the extent of neutralization of the chemical disinfectant and are intended to optimize on-site disinfection practices for waste matrices posing high microbial risks. Hence, there is a need for effective and reproducible neutralization protocols in chemical disinfection trials and practice. Furthermore, for most of chemical disinfectants used in healthcare settings there is no practical methodology to reliably and conveniently measure the residual disinfectant concentration after its neutralization and also determine the optimum concentration of the neutralizer. Because some neutralizing compounds can themselves be toxic to the test microorganisms, it is necessary to optimize neutralization procedures in disinfection experiments for the development of infection control practices using accepted positive control microbes. In the presented work, a stepwise bioassay-based protocol using representative faecal indicator microbes is described for optimizing chemical disinfection and subsequent disinfectant neutralization of any infectious faecal waste matrix. The example described is for the quaternary ammonium compound benzalkonium chloride and its recommended chemical neutralizer in a high strength human faecal waste matrix.

Transfer of Enteric Viruses Adenovirus and Coxsackievirus and Bacteriophage MS2 from Liquid to Human Skin

Enteric viruses (viruses that infect the gastrointestinal tract) are responsible for most water-transmitted diseases. They are shed in high concentrations in the feces of infected individuals, persist for an extended period of time in water, and are highly infective. Exposure to contaminated water directly (through ingestion) or indirectly (for example, through hand-water contacts followed by hand-to-mouth contacts) increases the risk of virus transmission. The work described herein provides a quantitative model for estimating human-pathogenic virus retention on skin following contact with contaminated water. The work will be important in refining the contribution of indirect transmission of virus to risks associated with water-related activities.

Indirect exposure to waterborne viruses increases the risk of infection, especially among children with frequent hand-to-mouth contacts. Here, we quantified the transfer of one bacteriophage (MS2) and two enteric viruses (adenovirus and coxsackievirus) from liquid to skin. MS2, a commonly used enteric virus surrogate, was used to compare virus transfer rates in a volunteer trial to those obtained using human cadaver skin and synthetic skin. MS2 transfer to volunteer skin was similar to transfer to cadaver skin but significantly different from transfer to synthetic skin. The transfer of MS2, adenovirus, and coxsackievirus to cadaver skin was modeled using measurements for viruses attaching to the skin (adsorbed) and viruses in liquid residual on skin (unadsorbed). We find virus transfer per surface area is a function of the concentration of virus in the liquid and the film thickness of liquid retained on the skin and is estimable using a linear model. Notably, the amount of MS2 adsorbed on the skin was on average 5 times higher than the amount of adenovirus and 4 times higher than the amount of coxsackievirus. Quantification of pathogenic virus retention to skin would thus be overestimated using MS2 adsorption data. This study provides models of virus transfer useful for risk assessments of water-related activities, demonstrates significant differences in the transfer of pathogenic virus and MS2, and suggests cadaver skin as an alternative testing system for studying interactions between viruses and skin.

IMPORTANCE Enteric viruses (viruses that infect the gastrointestinal tract) are responsible for most water-transmitted diseases. They are shed in high concentrations in the feces of infected individuals, persist for an extended period of time in water, and are highly infective. Exposure to contaminated water directly (through ingestion) or indirectly (for example, through hand-water contacts followed by hand-to-mouth contacts) increases the risk of virus transmission. The work described herein provides a quantitative model for estimating human-pathogenic virus retention on skin following contact with contaminated water. The work will be important in refining the contribution of indirect transmission of virus to risks associated with water-related activities.

Antibacterial efficacy of handrubbing for 15 versus 30 seconds: EN 1500-based randomized experimental study with different loads of Staphylococcus aureus and Escherichia coli

OBJECTIVES

Compliance with the World Health Organization 'how to handrub' action is suboptimal. Simplifying the hand-hygiene action may improve practice. However, it is crucial to preserve antibacterial efficacy. We tested the non-inferiority of 15 versus 30 seconds handrubbing for Staphylococcus aureus and Escherichia coli contamination at different loads, using hand-size customized alcohol-based handrub (ABHR) volumes.

METHODS

In an EN1500-based study, 18 health-care workers (HCWs) with extensive experience in hand hygiene rubbed hands with a hand-size customized volume of isopropanol 60% v/v. They repeated the following sequence: hand contamination (E. coli or S. aureus; broth containing 10⁸ or 10⁶ CFU/mL); baseline fingertips sampling; handrubbing (15 or 30 seconds); re-sampling. The main outcome was log₁₀ CFU corrected reduction factor (cRF) on HCWs' hands, applying a generalized linear mixed model with a random intercept for subject.

RESULTS

The median cRF was 2.1 log₁₀ (interquartile range 1.50-3.10). After fitting the model, cRF was significantly higher for S. aureus compared with E. coli but there was no significant effect for duration of handrubbing or contamination fluid concentration. Fifteen seconds of handrubbing was non-inferior to 30 (-0.06 log₁₀, 95% CI -0.34 to 0.22; EN1500 0.60 log₁₀ non-inferiority margin). This was confirmed in all pre-specified subgroups.

CONCLUSION

Among experienced HCWs using a hand-size customized volume of ABHR, handrubbing for 15 seconds was non-inferior to 30 seconds in reducing bacterial load, irrespective of type of bacteria or contamination fluid concentration. This provides further support for a shorter, 15-seconds, hand-hygiene action.

Bactericidal and Virucidal Activity of Povidone-Iodine and Chlorhexidine Gluconate Cleansers in an In Vivo Hand Hygiene Clinical Simulation Study

Introduction

Standard in vitro and in vivo tests help demonstrate efficacy of hand hygiene products; however, there is no standard in vivo test method for viruses. We investigated the bactericidal and virucidal efficacy of povidone-iodine (PVP-I) 7.5% scalp and skin cleanser, chlorhexidine gluconate (CHG) 4% hand cleanser and the reference hand wash (soft soap) in 15 healthy volunteers following European Standard EN1499 (hygienic hand wash test method for bacteria), which was adapted for virucidal testing.

Methods

Separate test series were performed for bactericidal (Escherichia coli) and virucidal [murine norovirus (MNV)] testing. After pre-washing and artificial contamination of hands with test organisms, volunteers underwent testing with 3 and 5 mL of each product for contact times of 15, 30 and 60 s according to a Latin-square randomization. The number of test organisms released from fingertips into sampling fluids was assessed before and after hand washing and mean log₁₀ reduction factor (RF) was calculated. RFs (test-reference) were compared using a Wilcoxon–Wilcox multiple comparisons test per EN1499; efficacy was concluded if p ≤ 0.01.

Results

PVP-I 7.5% and CHG 4% cleansers both passed EN1499 requirements against E. coli, with statistically significantly greater (p ≤ 0.01) mean log₁₀ RFs compared with reference soft soap across all tests (PVP-I: 4.09–5.27; CHG: 4.12–5.22; soap: 2.75–3.11). The experimental design using EN1499 was applicable to testing with MNV as discriminatory and reproducible results were generated. Mean log₁₀ RFs of MNV were statistically significantly greater for PVP-I (1.57–2.57) compared with soft soap (1.24–1.62), while mean log₁₀ RFs with CHG (0.90–1.34) were lower than for soft soap across all tests.

Conclusion

PVP-I 7.5% cleanser showed superior efficacy against MNV compared to soft soap and CHG 4% cleanser, while both PVP-I and CHG were superior to soft soap against E. coli. The experimental set-up may be applicable to future testing for antiviral hand washes.

Funding

Mundipharma Manufacturing Pte Ltd.

Plain Language Summary

Plain language summary available for this article.

Research on Handwashing Techniques of Peritoneal Dialysis Patients From Yiwu, Southeast China

The aim of the present study was to evaluate handwashing technique, bacteriology, and factors influencing handwashing technique of 86 stable chronic peritoneal dialysis (PD) patients from Yiwu City in Southeast China. Based on the "Hygienic standard for disinfection in the hospital", we also performed sampling for bacteriology from PD operators after they washed their hands. We compared their clinical features including the pathogenic bacteria of their previous peritonitis episodes and their handwashing evaluation results according to their bacteriologic sampling results. 65% of patients turned off the tap by bare hand, and 74% did not follow the six-step handwashing method. Dialysis duration longer than 6 months (P = 0.04) and lower income (P = 0.05) were independent risk factors for higher handwashing error scores. The overall rate of appropriate handwashing, according to the "hygienic standard for disinfection in the hospital" was 26%. The bacteriologic sampling results showed that the most common pathogenic bacterium was Staphylococcus aureus (92%). PD operators whose hand bacteria culture was qualified contained a lower proportion of participants with advanced age (P = 0.07). Patients with repeated peritonitis occurrence had a significantly higher score on handwashing error (P < 0.01) and were more likely to develop Staphylococcus infection. We found that in Yiwu city patients on dialysis for more than 6 months, were of low income and had multiple prior episodes of PD peritonitis had poor handwashing compliance. Elderly patients had higher rates of positive bacterial culture (Staphylococcus) from their hands.

Handwashing, but how? Microbial effectiveness of existing handwashing practices in high-density suburbs of Harare, Zimbabwe

BACKGROUND

Consistent domestic hand hygiene can reduce diarrhea-related morbidity and mortality and the spread of other communicable diseases. However, it remains uncertain which technique of handwashing is most effective and practicable during everyday life. The goal of this study is to determine how the handwashing technique, as performed in the daily life by the participants of this case study in Harare, Zimbabwe, influences microbial handwashing effectiveness.

METHODS

Handwashing technique of 173 primary caregivers was observed in their homes and hand rinse samples were collected before and after handwashing. Samples were analyzed for Escherichia coli and total coliform concentrations. Generalized linear models were used to predict fecal hand contamination after washing from observed handwashing technique.

RESULTS

Cleaning under fingernails, scrubbing the fingertips, using soap, and drying hands through rubbing on clothes or a clean towel statistically significantly reduced E coli contamination of hands after washing. Tap use, scrubbing fingertips, and rubbing hands on clothes to dry them statistically significantly reduced total coliform contamination.

CONCLUSIONS

Recommendations for effective and practicable domestic handwashing in Harare, Zimbabwe, should include performing specific handscrubbing steps (ie, cleaning under the fingernails and rubbing the fingertips), and soap and tap use. This calls for further research to develop behavior change interventions that explicitly promote effective handwashing technique at critical times.

Evaluating the effectiveness of real-time feedback on the bedside hand hygiene behaviors of nursing students

BACKGROUND

Traditional hand hygiene teaching methods lack long-term effectiveness.

METHOD

A longitudinal, within-subject design explored the influence of real-time hand microbe feedback and a critical-thinking decision exercise on nursing student hand hygiene behaviors. In three community hospitals, the students' (n = 68) hand swabs were tested for normal flora, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant Enterococcus at three time points. Students completed the Partnering to Heal (PTH) online exercise on hospital-acquired infection prevention decisions.

RESULTS

Normal flora colony counts decreased across the semester and MRSA-positive cultures increased in frequency and colony counts. MRSA-positive cultures were not associated with caring for patients in isolation precautions. Significantly higher colony counts were noted in the students who completed the PTH than those who did not complete the PTH.

CONCLUSION

This study explores innovative pedagogy bringing the nonvisible microbial risk to the consciousness of nursing students in an attempt to change hand hygiene behaviors.

Microbiological evaluation of the efficacy of soapy water to clean hands: a randomized, non-inferiority field trial

We conducted a randomized, non-inferiority field trial in urban Dhaka, Bangladesh among mothers to compare microbial efficacy of soapy water (30 g powdered detergent in 1.5 L water) with bar soap and water alone. Fieldworkers collected hand rinse samples before and after the following washing regimens: scrubbing with soapy water for 15 and 30 seconds; scrubbing with bar soap for 15 and 30 seconds; and scrubbing with water alone for 15 seconds. Soapy water and bar soap removed thermotolerant coliforms similarly after washing for 15 seconds (mean log10 reduction = 0.7 colony-forming units [CFU], P < 0.001 for soapy water; mean log10 reduction = 0.6 CFU, P = 0.001 for bar soap). Increasing scrubbing time to 30 seconds did not improve removal (P > 0.05). Scrubbing hands with water alone also reduced thermotolerant coliforms (mean log10 reduction = 0.3 CFU, P = 0.046) but was less efficacious than scrubbing hands with soapy water. Soapy water is an inexpensive and microbiologically effective cleansing agent to improve handwashing among households with vulnerable children.

Managing transmission of carbapenem-resistant enterobacteriaceae in healthcare settings: a view from the trenches

In 2011, the National Institutes of Health Clinical Center experienced a cluster of infection and colonization caused by carbapenem-resistant Klebsiella pneumoniae among profoundly immunocompromised inpatients. This manuscript describes the approach and interventions that were implemented in an attempt to curtail the cluster. Interventions employed included engagement of all stakeholders involved in care of at-risk patients; detailed and frequent communication with hospital staff about issues relating to the outbreak; aggressive microbial surveillance; use of techniques that facilitate rapid identification of resistant organisms; rapid characterization of resistance mechanisms; whole-genome sequencing of outbreak isolates to characterize the spread and to investigate mechanisms of healthcare-associated spread; implementation of enhanced contact precautions for all infected or colonized patients; geographic and personnel cohorting; daily chlorhexidine gluconate baths; dedicating equipment to be used solely for cohorted patients and aggressive decontamination of equipment that had to be reused on uncohorted patients; monitoring adherence to infection control precautions, including unwavering attention to adherence to appropriate hand hygiene procedures; and attention to the details of environmental decontamination. In addition, the manuscript discusses some of the challenges associated with managing such an event, as well as a few of the unanticipated consequences associated with the aftermath of the case cluster.

The hygienic efficacy of different hand-drying methods: a review of the evidence

The transmission of bacteria is more likely to occur from wet skin than from dry skin; therefore, the proper drying of hands after washing should be an integral part of the hand hygiene process in health care. This article systematically reviews the research on the hygienic efficacy of different hand-drying methods. A literature search was conducted in April 2011 using the electronic databases PubMed, Scopus, and Web of Science. Search terms used were hand dryer and hand drying. The search was limited to articles published in English from January 1970 through March 2011. Twelve studies were included in the review. Hand-drying effectiveness includes the speed of drying, degree of dryness, effective removal of bacteria, and prevention of cross-contamination. This review found little agreement regarding the relative effectiveness of electric air dryers. However, most studies suggest that paper towels can dry hands efficiently, remove bacteria effectively, and cause less contamination of the washroom environment. From a hygiene viewpoint, paper towels are superior to electric air dryers. Paper towels should be recommended in locations where hygiene is paramount, such as hospitals and clinics.

Bacterial reduction of alcohol-based liquid and gel products on hands soiled with blood

The antibacterial efficacy of three alcohol-based products (liquid and gel) were tested on the hands with blood and contaminated with Serratia marcescens (ATCC 14756), using EN 1500 procedures in 14 healthy volunteers. The alcohol-based products tested, either gel or liquid-based, reached bacterial reduction levels higher than 99.9% in the presence of blood and did not differ significantly (ANOVA test; P = 0.614).

Quest for a realistic in vivo test method for antimicrobial hand-rub agents: introduction of a low-volume hand contamination procedure

A novel method has been developed for the evaluation of alcohol-based hand rubs (ABHR) that employs a hand contamination procedure that more closely simulates the in-use conditions of ABHR. Hands of human subjects were contaminated with 0.2 ml of a concentrated suspension of Serratia marcescens (ATCC 14756) to achieve baseline contamination between 8 and 9 log₁₀ CFU/hand while allowing product to be applied to dry hands with minimal soil load. Evaluation of 1.5 ml of an ABHR gel containing 62% ethanol produced log₁₀ reductions of 2.66 ± 0.96, 2.40 ± 0.50, 2.41 ± 0.61, and 2.33 ± 0.49 (means ± standard deviations) after 1, 3, 7, and 10 successive contamination/product application cycles. In a study comparing this low-volume contamination (LVC) method to ASTM E1174, product dry times were more realistic and log₁₀ reductions achieved by the ABHR were significantly greater when LVC was employed (P < 0.05). These results indicate that a novel low-volume hand contamination procedure, which more closely represents ABHR use conditions, provides more realistic estimates of in-use ABHR efficacies. Based on the LVC method, log₁₀ reductions produced by ABHR were strongly dependent on the test product application volume (P < 0.0001) but were not influenced by the alcohol concentration when it was within the range of 62 to 85% (P = 0.378).

Evaluation of handwashing behaviors and analysis of hand flora of intensive care unit nurses

PURPOSE

The aim of this study was to evaluate the handwashing behaviors of intensive care nurses based on personal statements, and to identify the microorganisms represented in the hand flora preshift and postshift.

METHODS

This prospective study was performed with 60 intensive care nurses between January and December 2008, at a training and research hospital at a university in Turkey. Samples were taken from the hands of the nurses for bacteriological culture, using the bag-broth method, at the beginning and end of the shift. The samples were cultured aerobically and the colonies that grew were counted and identified. The nurses completed a self-report questionnaire, and their answers were evaluated.

RESULTS

The frequency of handwashing by participants during each shift was 32.8±13.9. Overall, 65% of the nurses preferred alcohol-based antiseptic solutions for handwashing, 95% used paper towels to dry their hands, and 98.3-100% of the nurses washed their hands after performing care procedures. The Escherichia coli and coagulase negative Staphylococcus species were found to be at significantly higher levels in the postshift hand culture samples when compared to the preshift hand culture sample values. Enterobacter cloacae was the only species found in the postshift hand culture samples of the nurses.

CONCLUSIONS

The number of colonies of the microorganisms in the hand flora of the nurses increased postshift. The handwashing behavior of intensive care nurses must be improved as they nurse critical patients.

Efficacy of waterless hand hygiene compared with handwashing with soap: a field study in Dar es Salaam, Tanzania

Effective handwashing with soap requires reliable access to water supplies. However, more than three billion persons do not have household-level access to piped water. This research addresses the challenge of improving hand hygiene within water-constrained environments. The antimicrobial efficacy of alcohol-based hand sanitizer, a waterless hand hygiene product, was evaluated and compared with handwashing with soap and water in field conditions in Dar es Salaam, Tanzania. Hand sanitizer use by mothers resulted in 0.66 and 0.64 log reductions per hand of Escherichia coli and fecal streptococci, respectively. In comparison, handwashing with soap resulted in 0.50 and 0.25 log reductions per hand of E. coli and fecal streptococci, respectively. Hand sanitizer was significantly better than handwashing with respect to reduction in levels of fecal streptococci (P = 0.01). The feasibility and health impacts of promoting hand sanitizer as an alternative hand hygiene option for water-constrained environments should be assessed.

Microbiological efficacy and tolerability of a new, non-alcohol-based hand disinfectant

OBJECTIVE

Alcohol-based hand disinfectants are widely used in hospitals. Occasionally, there is a need for non-alcohol-based products, but alternatives have been scarce. We studied the microbiological efficacy and tolerability of a water-based hand disinfectant for healthcare workers.

DESIGN

A water-based hand disinfectant was introduced as the only hand disinfectant in 5 wards in Turku University Hospital, Finland. Ninety-nine healthcare workers participated in fingerprint sampling during the 7-week study period. In another ward, 26 healthcare workers who were using alcohol-based hand disinfectant acted as control subjects for the skin reaction studies. The water-based product was tested in the laboratory according to the European standard EN 12791. We obtained 292 fingerprint samples before disinfection and 302 after disinfection. The opinions of healthcare workers were collected by use of a questionnaire, and skin reactions were assessed subjectively by use of questionnaires and objectively by measuring moisture and transepidermal water loss.

RESULTS

When tested in accordance with the European standard, the product met the requirements for short-term and long-term efficacy. The results of the fingerprint test showed that there was a statistically significant decrease in colonization of the fingertips before and after disinfection (P<.001). The users of the water-based hand disinfectant reported dry skin more often than did control subjects, but visual inspection and the results of the moisture measurement showed no difference between the users of the water-based hand disinfectant and the control subjects. Transepidermal water loss measurement also showed no deterioration of skin condition.

CONCLUSIONS

The water-based hand disinfectant was shown to be an effective hand disinfectant that caused relatively little skin irritation and can serve as a hand hygiene alternative in situations in which alcohol-based disinfectant cannot be used.

Alternative hand contamination technique to compare the activities of antimicrobial and nonantimicrobial soaps under different test conditions

Antimicrobial hand soaps provide a greater bacterial reduction than nonantimicrobial soaps. However, the link between greater bacterial reduction and a reduction of disease has not been definitively demonstrated. Confounding factors, such as compliance, soap volume, and wash time, may all influence the outcomes of studies. The aim of this work was to examine the effects of wash time and soap volume on the relative activities and the subsequent transfer of bacteria to inanimate objects for antimicrobial and nonantimicrobial soaps. Increasing the wash time from 15 to 30 seconds increased reduction of Shigella flexneri from 2.90 to 3.33 log(10) counts (P = 0.086) for the antimicrobial soap, while nonantimicrobial soap achieved reductions of 1.72 and 1.67 log(10) counts (P > 0.6). Increasing soap volume increased bacterial reductions for both the antimicrobial and the nonantimicrobial soaps. When the soap volume was normalized based on weight (approximately 3 g), nonantimicrobial soap reduced Serratia marcescens by 1.08 log(10) counts, compared to the 3.83-log(10) reduction caused by the antimicrobial soap (P < 0.001). The transfer of Escherichia coli to plastic balls following a 15-second hand wash with antimicrobial soap resulted in a bacterial recovery of 2.49 log(10) counts, compared to the 4.22-log(10) (P < 0.001) bacterial recovery on balls handled by hands washed with nonantimicrobial soap. This indicates that nonantimicrobial soap was less active and that the effectiveness of antimicrobial soaps can be improved with longer wash time and greater soap volume. The transfer of bacteria to objects was significantly reduced due to greater reduction in bacteria following the use of antimicrobial soap.

Effect of hand wash agents on controlling the transmission of pathogenic bacteria from hands to food

The goals of this study were to evaluate the effectiveness of two hand wash regimens in reducing transient bacteria on the skin following a single hand wash and the subsequent transfer of the bacteria to a ready-to-eat food item, freshly cut cantaloupe melon. The number of bacteria recovered from hands and the quantity transferred to the melon were significantly less following the use of an antibacterial soap compared with plain soap. The antimicrobial soap achieved > 3-log reductions versus Escherichia coli and 3.31- and 2.83-log reductions versus Shigella flexneri. The plain soap failed to achieve a 2-log reduction against either organism. The bacteria recovered from the melon handled by hands treated with antimicrobial hand soap averaged 2 log. Melon handled following hand washing with plain soap had > 3 log bacteria in the experiments. Based on previously published feeding studies, an infection rate in the range of approximately 15 to 25% would be expected after ingesting melon containing 2 log CFU compared with ingesting greater than the 3 log transferred from hands washed with plain soap, which would result in a higher infection attack rate of 50 to 80%. The data thus demonstrate there is a greater potential to reduce the transmission and acquisition of disease through the use of an antimicrobial hand wash than through the use of plain soap.

Consumer antibacterial soaps: effective or just risky?

BACKGROUND

Much has been written recently about the potential hazards versus benefits of antibacterial (biocide)-containing soaps. The purpose of this systematic literature review was to assess the studies that have examined the efficacy of products containing triclosan, compared with that of plain soap, in the community setting, as well as to evaluate findings that address potential hazards of this use--namely, the emergence of antibiotic-resistant bacteria.

METHODS

The PubMed database was searched for English-language articles, using relevant keyword combinations for articles published between 1980 and 2006. Twenty-seven studies were eventually identified as being relevant to the review.

RESULTS

Soaps containing triclosan within the range of concentrations commonly used in the community setting (0.1%-0.45% wt/vol) were no more effective than plain soap at preventing infectious illness symptoms and reducing bacterial levels on the hands. Several laboratory studies demonstrated evidence of triclosan-adapted cross-resistance to antibiotics among different species of bacteria.

CONCLUSIONS

The lack of an additional health benefit associated with the use of triclosan-containing consumer soaps over regular soap, coupled with laboratory data demonstrating a potential risk of selecting for drug resistance, warrants further evaluation by governmental regulators regarding antibacterial product claims and advertising. Further studies of this issue are encouraged.

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

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

Comparative efficacy of hand hygiene agents in the reduction of bacteria and viruses

Background

Health care-associated infections most commonly result from person-to-person transmission via the hands of health care workers.

Methods

We studied the efficacy of hand hygiene agents (n = 14) following 10-second applications to reduce the level of challenge organisms (Serratia marcescens and MS2 bacteriophage) from the hands of healthy volunteers using the ASTM-E-1174-94 test method.

Results

The highest log₁₀ reductions of S marcescens were achieved with agents containing chlorhexidine gluconate (CHG), triclosan, benzethonium chloride, and the controls, tap water alone and nonantimicrobial soap and water (episode 1 of hand hygiene, 1.60-2.01; episode 10, 1.60-3.63). Handwipes but not alcohol-based handrubs were significantly inferior from these agents after a single episode of hand hygiene, but both groups were significantly inferior after 10 episodes. After a single episode of hand hygiene, alcohol/silver iodide, CHG, triclosan, and benzethonium chloride were similar to the controls in reduction of MS2, but, in general, handwipes and alcohol-based handrubs showed significantly lower efficacy. After 10 episodes, only benzethonium chloride (1.33) performed as well as the controls (1.59-1.89) in the reduction of MS2.

Conclusions

Antimicrobial handwashing agents were the most efficacious in bacterial removal, whereas waterless agents showed variable efficacy. Alcohol-based handrubs compared with other products demonstrated better efficacy after a single episode of hand hygiene than after 10 episodes. Effective hand hygiene for high levels of viral contamination with a nonenveloped virus was best achieved by physical removal with a nonantimicrobial soap or tap water alone.