Comparison of the efficacy and drying times of liquid, gel and foam formats of alcohol-based hand rubs

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.

Updates and future directions regarding hand hygiene in the healthcare setting: insights from the 3rd ICPIC alcohol-based handrub (ABHR) task force

Healthcare-associated infections (HAIs) and antimicrobial resistance (AMR) pose threats to global health. Effective hand hygiene is essential for preventing HAIs and the spread of AMR in healthcare. We aimed to highlight the recent progress and future directions in hand hygiene and alcohol-based handrub (ABHR) use in the healthcare setting. In September 2023, 42 experts in infection prevention and control (IPC) convened at the 3rd International Conference on Prevention and Infection Control (ICPIC) ABHR Taskforce in Geneva, Switzerland. The purpose of this meeting was to provide a synthesis of recent evidence and formulate a research agenda on four critical areas for the implementation of effective hand hygiene practices: (1) ABHR formulations and hand rubbing techniques, (2) low-resource settings and local production of ABHR, (3) hand hygiene monitoring and technological innovations, and (4) hand hygiene standards and guidelines.

Current issues in hand hygiene

BACKGROUND

Multiple aspects of hand hygiene have changed in recent years.

METHODS

A PubMed search was conducted to identify recent articles about hand hygiene.

RESULTS

The COVID-19 pandemic caused temporary changes in hand hygiene compliance rates and shortages of alcohol-based hand sanitizers (ABHSs), and in marketing of some products that were ineffective or unsafe. Fortunately, ABHSs are effective against SARS-CoV-2 and other emerging pathogens including Candida auris and mpox. Proper placement, maintenance, and design of ABHS dispensers have gained additional attention. Current evidence suggests that if an adequate volume of ABHS has been applied to hands, personnel must rub their hands together for at least 15 seconds before hands feel dry (dry time), which is the primary driver of antimicrobial efficacy. Accordingly, practical methods of monitoring hand hygiene technique are needed. Direct observation of hand hygiene compliance remains a challenge in many healthcare facilities, generating increased interest in automated hand hygiene monitoring systems (AHHMSs). However, several barriers have hindered widespread adoption of AHHMSs. AHHMSs must be implemented as part of a multimodal improvement program to successfully improve hand hygiene performance rates.

CONCLUSIONS

Remaining gaps in our understanding of hand hygiene warrant continued research into factors impacting hand hygiene practices.

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.

Comparing the effectiveness of hand hygiene techniques in reducing the microbial load and covering hand surfaces in healthcare workers: Updated systematic review

BACKGROUND

This review, commissioned by the World Health Organization (WHO), examined the effectiveness of the WHO 6-step hand hygiene (HH) technique in reducing microbial load on hands and covering hand surfaces, and compared its effectiveness to other techniques.

METHODS

Medline, CINAHL, ProQuest, Web of Science, Mednar, and Google Scholar were searched for primary studies, published in English (1978-February 2021), evaluating the microbiological effectiveness or hand surface coverage of HH techniques in healthcare workers. Reviewers independently performed quality assessment using Cochrane tools. The protocol for the narrative review was registered (PROSPERO 2021: CRD42021236138).

RESULTS

Nine studies were included. Evidence demonstrated that the WHO technique reduced microbial load on hands. One study found the WHO technique more effective than the 3-step technique (P = .02), while another found no difference between these 2 techniques (P = .08). An adapted 3-step technique was more effective than the WHO technique in laboratory settings (P = .021), but not in clinical practice (P = .629). One study demonstrated that an adapted 6-step technique was more effective than the WHO technique (P = .001). Evidence was heterogeneous in application time, product, and volume. All studies were high risk of bias.

CONCLUSIONS

Eight studies found that the WHO 6-step technique reduced microbial load on healthcare workers' hands; but the studies were heterogeneous and further research is required to identify the most effective, yet feasible technique.

Disinfectants against SARS-CoV-2: A Review

The pandemic due to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has emerged as a serious global public health issue. Besides the high transmission rate from individual to individual, indirect transmission from inanimate objects or surfaces poses a more significant threat. Since the start of the outbreak, the importance of respiratory protection, social distancing, and chemical disinfection to prevent the spread of the virus has been the prime focus for infection control. Health regulatory organizations have produced guidelines for the formulation and application of chemical disinfectants to manufacturing industries and the public. On the other hand, extensive literature on the virucidal efficacy testing of microbicides for SARS-CoV-2 has been published over the past year and a half. This review summarizes the studies on the most common chemical disinfectants and their virucidal efficacy against SARS-CoV-2, including the type and concentration of the chemical disinfectant, the formulation, the presence of excipients, the exposure time, and other critical factors that determine the effectiveness of chemical disinfectants. In this review, we also critically appraise these disinfectants and conduct a discussion on the role they can play in the COVID-19 pandemic.

The application of normative documents for determination of biocidal activity of disinfectants and antiseptics dedicated for medical area: a narrative review

Disinfectants and antiseptics are important weapons to reduce the number of microorganisms and thus to limit the number of infections. Different methods of antimicrobial activity testing, often not standardised, without appropriate controls and not validated are applied. To address these issues, several European Standards (EN) have been developed, describing the test methods to determine whether chemical disinfectants or antiseptic products have appropriate bactericidal, sporicidal, mycobactericidal or tuberculocidal activity; fungicidal or yeasticidal activity; or virucidal activity. In this narrative review, the 17 EN concerning evaluation of the above-mentioned antimicrobial activity of preparations dedicated to the medical area are briefly reviewed, together with recent publications on this topic. Suspension and carrier tests have been performed in clean and dirty conditions simulating the medical area. In addition, a wide range of applications of these standards has been presented in the research of biocides for hand antisepsis, surfaces disinfection, including airborne disinfection as well as medical device and medical textile disinfection. The role of normative documents in the investigation of antimicrobial activity of disinfectants and antiseptics to limit infections has been underestimated. This narrative review aims to persuade researchers to conduct antimicrobial activity testing in line with validated EN and highlights an existing gap in ongoing research. It also aims to raise awareness of the wide range of biocidal activity tests with standardised methods in medical area. We also pay attention to the recently developed European Pharmacopoeia monography concerning the testing of bactericidal and fungicidal activity of antiseptics classified as medicinal products.

Downstream Approach Routes for the Purification and Recovery of Lactobionic Acid

The successful development of a lactobionic acid (LBA) bioconversion process on an industrial scale demands the selection of appropriate downstream methodological approaches to achieve product purification once the bioconversion of LBA is completed. These approaches depend on the nature of the substrate available for LBA production, and their necessary implementation could constitute a drawback when compared to the lesser effort required in downstream approaches in the production of LBA obtained by chemical synthesis from refined lactose. Thus, the aim of this research is to separate LBA from an acid whey substrate after bioconversion with Pseudomonas taetrolens. Freeze drying, crystallization, adsorption with activated carbon, microfiltration, centrifugation, and precipitation with 96% (v/v) ethanol were carried out to separate and purify LBA. The closest product to commercial LBA was obtained using precipitation with ethanol, obtaining a white powder with 95 ± 2% LBA concentration. The procedure described in this paper could help to produce LBA on an industrial scale via microbial bioconversion from acid whey, developing a promising biotechnological approach for lactose conversion.

Adaptation and validation of a method for evaluating the bactericidal activity of ethyl alcohol in gel format 70% (w/w)

Ethyl alcohol 70% (w/w) is a broad-spectrum bactericidal agent that is mandatorily marketed as a gel in Brazil since 2002. However, there is no method described for the microbiological quality control of surface disinfectants in the form of gel, which makes it impossible to monitor the effectiveness of these products by the Health Surveillance. Thus, the present study aimed to adapt an analytical method and validate it so that it is possible to evaluate the bactericidal activity of ethyl alcohol-based disinfectants at 70% (w/w) in gel form. The proposed analytical method is an adaptation of a method developed by the Association of Official Analytical Chemists (AOAC), which is currently used to evaluate the bacterial activity of disinfectants in the form of spray and aerosol. The method consisted of challenging the disinfectant by putting it in contact with 60 carriers - previously contaminated with the test microorganism - during the contact time established by the manufacturer. The bacteria used in this work were Staphylococcus aureus CBRVS 00039 ATCC 6538, Salmonella enterica CBRVS 00028 ATCC 10708, and Pseudomonas aeruginosa CBRVS 00025 ATCC 15442. The parameters chosen for the validation of the method were: matrix effect, robustness, and repeatability. The experiments performed with a disinfectant matrix showed that there is no interference of the gel on the effectiveness of alcohol. Satisfactory results regarding the evaluation of bactericidal activity were obtained for the three microorganisms tested when the volume of 100 μL of disinfectant was applied. The method also showed good repeatability, as it proved to be robust with modification of incubation times, equipment and analysts. The development and validation of this method were extremely important for the quality monitoring of these products, besides being the first method described for the evaluation of gel disinfectants.

Hand Hygiene, an Update

Hand hygiene by health care personnel is an important measure for preventing health care-associated infections, but adherence rates and technique remain suboptimal. Alcohol-based hand rubs are the preferred method of hand hygiene in most clinical scenarios, are more effective and better tolerated than handwashing, and their use has facilitated improved adherence rates. Obtaining accurate estimates of hand hygiene adherence rates using direct observations of personnel is challenging. Combining automated hand hygiene monitoring systems with direct observations is a promising strategy, and is likely to yield the best estimates of adherence. Greater attention to hand hygiene technique is needed.

Quick determination and discrimination of commercial hand sanitisers using attenuated total reflectance-Fourier transform infrared spectroscopy and chemometrics

Due to the outbreak of the COVID-19 pandemic, practicing personal hygiene such as frequent hand sanitising has become a norm. The making of effective hand sanitiser products should follow the recommended formulations, but the high demand worldwide for such affordable products could have made them a candidate for counterfeiting, thus deserving forensic determination and profiling for source determination or supply chain tracing. In this study, determination and discrimination of hand sanitisers was carried out by employing attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy combined with chemometrics. Fifty commercially available hand sanitisers were obtained from the market and analysed. ATR-FTIR profiles of each sanitiser were compared and decomposed by principal component analysis (PCA) followed by linear discriminant analysis (LDA). Physical observation enabled the discrimination of seven samples based on their respective colours, the presence of beads and their colours, and the physical forms of formulations. Subsequently, eight distinct patterns were observed through visual comparison of ATR-FTIR profiles of the remaining 43 samples. An initial unsupervised exploratory PCA model indicated the separation of two main groups with ATR-FTIR profiles similar to those of ethanol and isopropanol, respectively. The PCA score-LDA model provided good predictions, with a 100% correct classification into eight different groups. In conclusion, this study demonstrated a quick determination and discrimination of hand sanitiser samples, allowing screening for any restricted components and sample-to-sample comparison.

Characterization of commercial poultry farms in Mexico: Towards a better understanding of biosecurity practices and antibiotic usage patterns

Mexico is one of the world’s major poultry producing countries. Two significant challenges currently facing the poultry industry are the responsible and judicious use of antimicrobials, and the potential occurrence of infectious disease outbreaks. For example, repeated outbreaks of highly pathogenic avian influenza virus subtype H7N3 have occurred in poultry since its first detection in Mexico in 2012. Both of these challenges can be addressed through good husbandry practices and the application of on-farm biosecurity measures. The aims of this study were: (i) to assess the biosecurity measures practiced across different types of poultry farms in Mexico, and (ii) to collect information regarding antimicrobial usage. A cross-sectional study was carried out through on-farm interviews on 43 poultry farms. A multiple correspondence analysis was performed to characterize the farms based on their pattern of biosecurity practices and antimicrobial usage. Three clusters of farms were identified using an agglomerative hierarchical cluster analysis. In each cluster, a specific farm type was predominant. The biosecurity measures that significantly differentiated the visited farms, thus allowing their clusterization, were: the use of personal protective equipment (e.g. face masks, hair caps, and eye protection), the requirement for a hygiene protocol before and after entering the farm, the use of exclusive working clothes by staff and visitors, footbath presence at the barn entrance, and the mortality disposal strategy. The more stringent the biosecurity measures on farms within a cluster, the fewer the farms that used antimicrobials. Farms with more biosecurity breaches used antimicrobials considered critically important for public health. These findings could be helpful to understand how to guide strategies to reinforce compliance with biosecurity practices identified as critical according to the farm type. We conclude by providing certain recommendations to improve on-farm biosecurity measures.

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.

Product dose considerations for real-world hand sanitiser efficacy

BACKGROUND

Alcohol based hand rubs (ABHR) are extremely effective at reducing microbial contamination and have an essential role in best practice hand hygiene described by the World Health Organization.

METHODS

We determined ABHR drying time when performing hand hygiene in a laboratory setting. Which was followed by identifying the amount of ABHR needed for complete hand coverage. When the aforementioned was analyzed real-time data were gathered to examine the amount used for hand hygiene in a hospital setting. In parallel hands of healthcare workers (HCWs) were monitored for drying time and perception on ABHR use.

RESULTS

In 86% (24,446,397/28,280,383) of the events a single dose of ABHR was used on clinical wards. Twenty-four HCWs expected hand hygiene to take 7.5 seconds (median; range 3-30 seconds). Forty-three HCWs show that 1.5 mL ABHR dose achieves the desired drying time according to World Health Organization guidelines (av. median 26 seconds), but is consistently perceived to have a longer drying time than expected (av. median 18 seconds). In-vivo results (n = 10) indicate that 2.25 mL ABHR is required for adequate coverage (82%-90%) of both sides of the hand.

CONCLUSIONS

Results indicate that set standards for the use of ABHR do not match "in-vivo" behaviour of HCWs. Perceived drying times are shorter than actual drying time. The needed drying time to reach acceptable antimicrobial efficacy of ABHRs should be revisited.

Handrubbing with sprayed alcohol-based hand rub: an alternative method for effective hand hygiene

BACKGROUND

Hand hygiene is crucial in infection prevention and control. It is unclear whether sprayed alcohol-based hand rub (ABHR) is non-inferior to the World Health Organization (WHO)-recommended method of handrubbing with poured ABHR.

AIM

To test whether sprayed ABHR can be an alternative (non-inferior) method for effective hand hygiene with/without handrubbing.

METHODS

A laboratory experiment was conducted with ABHR (isopropanol 60% v/v) according to European Norm 1500. Hand hygiene was performed by: (1) handrubbing with ABHR poured on to the palm of the hand; (2) handrubbing with sprayed ABHR; and (3) applying sprayed ABHR to hands without handrubbing. Hands were contaminated with Escherichia coli ATCC 10536, followed by hand hygiene and microbiological sampling. A generalized linear mixed model with a random intercept per subject was used to analyse the reduction in bacterial count following hand hygiene.

FINDINGS

In total, 19 healthcare workers participated in the study. Handrubbing with sprayed ABHR was non-inferior [margin log₁₀ 0.6 colony-forming units (cfu)/mL] to the WHO-recommended method of handrubbing with poured ABHR; bacterial count reductions were log₁₀ 3.66 cfu/mL [95% confidence interval (CI) 1.68-5.64] and log₁₀ 3.46 cfu/mL (95% CI 1.27-5.65), respectively. Conversely, non-inferiority was not found for sprayed ABHR without handrubbing [bacterial count reduction log₁₀ 2.76 cfu/mL (95% CI 1.65-3.87)].

CONCLUSION

Handrubbing with sprayed ABHR was non-inferior to handrubbing with ABHR poured on to the palm of the hand to reduce bacterial counts on hands under experimental conditions. Handrubbing with sprayed ABHR may be an acceptable alternative hand hygiene method pending assessment in other settings and for other pathogens.

Acceptability and tolerability of alcohol-based hand hygiene products for elderly residents in long-term care: a crossover study

Background

Hand hygiene is a critical component of infection control. Much of the focus on improving hand hygiene in healthcare settings has been directed towards healthcare worker compliance but its importance for patients, including those in long-term care facilities (LTCFs), is increasingly being recognised. Alcohol-based hand rub (ABHR) can lead to improved compliance. We aimed to determine acceptability and tolerability of two ABHRs for hand hygiene of elderly LTCF residents using a modified version of the WHO protocol.

Methods

Thirty six elderly LTCF residents participated in this crossover study. A modified and translated (Chinese) version of the WHO protocol for evaluation of two or more ABHRs was used to determine product acceptability and tolerability for one gel (bottle with reclosable cap) and one foam (pump). During the 3-day testing period, participants were provided with their own portable bottle of ABHR. A research nurse objectively assessed the skin integrity of the hands at baseline and throughout the study. Skin moisture content was determined using a Scalar Moisture Checker Probe (Science Technology Resources, Ca, USA). Participants rated ABHR tolerability and acceptability using the WHO checklist at the end of each test period.

Results

Both products passed the WHO criteria for acceptability and tolerability. The foam (86%) scored higher than the gel (51%) for ease of use possibly because some participants found the cap of the gel bottle difficult to open due to finger stiffness. No evidence of damage to skin integrity was observed. Overall, skin moisture content had improved by the end of the study. Residents preferred either of the test products to the liquid formulation currently in use by the LTCF.

Conclusions

Overall, the elderly were willing to use ABHR for hand hygiene. Both products were well tolerated and preferred over the usual product provided by the LTCF. However, forgetfulness and difficulty rubbing the product over the hands due to finger stiffness posed a challenge for some residents. This could be overcome by using healthcare worker-assisted hand hygiene at specified times each day and prompts to serve as reminders to perform hand hygiene.

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.