Acceptability and tolerability of liquid versus gel and standard versus virucidal alcohol-based hand rub formulations among dental students

In Vitro Efficacy of Foam Hand Sanitizers Against Enveloped and Non-Enveloped Viruses

Enveloped and non-enveloped virus transmission can occur via person-to-person contact and potentially through contaminated surfaces with human hands. Establishing the efficacy of hand sanitizers, including gel and foam formats, is crucial in reducing the transmission of viruses of human health concern, yet foam hand sanitizers are generally underexplored despite being widely used. Following American Society for Testing and Materials (ASTM) E1052-20, the efficacy of foam-based hand sanitizers-one non-alcohol-based hand sanitizer and four alcohol-based hand sanitizers with benzalkonium chloride and ethanol as active ingredients, respectively-were explored using bacteriophage phi6 (Φ6) as a surrogate for enveloped viruses and bacteriophage MS2 (Emesvirus zinderi) and Tulane virus (TuV) as surrogates for non-enveloped viruses. Significant differences in log reduction were observed among viruses (P ≤ 0.05). After a 10 s exposure, a 5.23 ± 1.64 log reduction was observed for Φ6 while MS2 remained resistant (0.04 ± 0.08 log10 reduction). Conversely, significant log reductions (P ≤ 0.05) were observed for TuV across all foam-based hand sanitizer products ranging from 0.07 ± 0.1 to 1.09 ± 0.22. An exposure time of 10 s (i.e., the typical rubbing time in real-world scenarios following hand sanitizer application) is likely sufficient for enveloped virus inactivation based on the inactivation of bacteriophage Φ6 by the tested commercially available products. However, longer exposure times or different hand sanitizer formulations may be required to achieve similar log reductions against non-enveloped viruses such as human norovirus based on the surrogates (MS2, TuV) tested.

A comparative study on the effect of alcohol-based hand sanitizers in spray and gel formulation on the skin: A prospective, randomised, crossover trial

BACKGROUND

Many formulations of Alcohol-based hand rubs (ABHRs), such as liquid, gel, and spray have been developed and used for preventing infections. This study aimed to compare skin irritation from using ABHRs in gel and spray formulations.

METHOD

This was a prospective, randomised, crossover trial conducted to investigate the effect of skin irritation caused by ABHRs in gel compared to spray formulation after 21 days of using each formulation. Clinical outcomes were assessed using subjective Larson's skin assessment score and Frosch and Kligman observer skin assessment score, as well as bioengineering measures: transepidermal water loss (TEWL) and skin capacitance on days 3, 7, 14, and 21.

RESULTS

Among 38 participants, both formulations showed no significant change in clinical scores and skin capacitance during the study. However, TEWL increased significantly from baseline on day 3 (p = 0.029) for the spray formulation and on day 21 (p = 0.019) for the gel formulation, with no statistically significant difference between the formulations (p = 0.46).

CONCLUSION

Our research supports the safety of gel and spray ABHRs for regular use, with the only potential issue being mild skin irritation. For those with sensitive skin, the gel formulation is preferable.

Evidence-based hand hygiene: Liquid or gel handrub, does it matter?

BACKGROUND

Recent studies put under scrutiny the prevailing hand hygiene guidelines, which incorporate quantitative parameters regarding handrub volume and hand size. Understanding the criticality of complete (i.e., efficient) hand hygiene in healthcare, objectivization of hand hygiene related parameters are paramount, including the formulation of the ABHR. Complete coverage can be achieved with optimal Alcohol-Based Hand Rub (ABHR) provided. The literature is limited regarding ABHR formulation variances to antimicrobial efficiency and healthcare workers' preference, while public data on clinically relevant typical application differences is not available. This study was designed and performed to compare gel and liquid format ABHRs (the two most popular types in Europe) by measuring several parameters, including application time, spillage and coverage.

METHODOLOGY

Senior medical students were invited, and randomly assigned to receive pre-determined ABHR volumes (1.5 or 3 ml). All the 340 participants were given equal amounts of gel and liquid on two separate hand hygiene occasions, which occurred two weeks apart. During the hand hygiene events, by employing a digital, fully automated system paired with fluorescent-traced ABHRs, disinfectant hand coverage was objectively investigated. Furthermore, hand coverage in relation to the participants' hand sizes was also calculated. Additional data collection was performed regarding volume differences and their effect on application time, participants' volume awareness (consciousness) and disinfectant spillage during the hand hygiene events.

RESULTS

The 1.5 ml ABHR volume (commonly applied in healthcare settings) is insufficient in either formulation, as the non-covered areas exceeded significant (5%+) of the total hand surface area. 3 ml, on the contrary, resulted in almost complete coverage (uncovered areas remained below 1.5%). Participants typically underestimated the volume which they needed to apply. While the liquid ABHR spreads better in the lower, 1.5 ml volume compared to the gel, the latter was easier handled at larger volume. Drying times were 30/32 s (gel and liquid formats, respectively) when 1.5 ml handrub was applied, and 40/42 s when 3 ml was used. As the evaporation rates of the ABHR used in the study are similar to those available on the market, one can presume that the results presented in the study apply for most WHO conform ABHRs.

CONCLUSION

The results show that applying 1.5 ml volume was insufficient, as large part of the hand surface remained uncovered (7.0 ± 0.7% and 5.8 ± 1.0% of the hand surface in the case of gel and liquid, respectively) When 3 ml handrub was applied drying times were 40 and 42 s (gel and liquid, respectively), which is a very long time in daily clinical practice. It looks like we cannot find a volume that fits for everyone. Personalized, hand size based ABHR volumes may be the solution to find an optimal balance between maximize coverage and minimise spillage and drying time. 3 ml can be a good volume for those who have medium size hands. Large handed people should use more handrub to reach appropriate coverage, while small-handed ones may apply less to avoid massive spillage and not to take unrealistically long to dry.

Evaluation of the Efficiency of Hand Hygiene Technique with Hydroalcoholic Solution by Image Color Summarize

Background and Objectives: The HH (hand hygiene) technique is relatively simple. Even so, in practice there are still non-conformities regarding this aspect. Lack of knowledge or lack of compliance can be reasons for non-adherence with HH techniques. In this context, the purpose of this study was to follow the realization of the hand-washing technique with hydroalcoholic solution, applied before and after receiving the HH recommendations. Materials and Methods: A descriptive, cross-sectional study was conducted from May 2022 to June 2022. Students from a second year dental medicine class teaching in French 2021/22 “Grigore T. Popa” University of Medicine and Pharmacy in Iasi were included in the study. The approval of the ethics commission was received: No. 184/05.05.2022. The study was conducted in two stages. In the first stage, HH was performed without any recommendation. In the second stage, the antiseptic hand rubbing technique was presented following the WHO recommendations. The fluorescent Fluo-Add solution, Wood lamp for dermatology (4 × 5.5 W ultraviolet tubes with a wavelength of 360 nm), and photo camera were used. Subjects performed their HH movement before and after receiving instructions according to WHO. Images were initially taken from the backhand and palm and were finally analyzed with Image Color Summarizer. The data were analyzed by the Mann–Whitney U Test, t-test paired samples using IBM-SPSS version 26 (IBM, Armonk, NY, USA), and p ≤ 0.05 was considered statistically significant. Results: After analyzing the images, there were 70 subjects, 45.7% (32) female and 54.33% (38) male. Final average covered area of backhand was 60.89% (±17.17), 28.84:86.11, compared to 52.07% (±17.04), 9:85.23. Final average covered area for palm was 69.91% (±13.5), 31.61:93.41 compared to 59.74% (±16.64), 26.13:92.72. No statistical significance was obtained by gender. Conclusions: The study showed an improvement in hand hygiene technique without highlighting gender differences.

Hand sanitizers: A review of ingredients, mechanisms of action, modes of delivery, and efficacy against coronaviruses

Background

The emergence of the novel virus, SARS-CoV-2, has posed unprecedented challenges to public health around the world. Currently, strategies to deal with COVID-19 are purely supportive and preventative, aimed at reducing transmission. An effective and simple method for reducing transmission of infections in public or healthcare settings is hand hygiene. Unfortunately, little is known regarding the efficacy of hand sanitizers against SARS-CoV-2.

Methods

In this review, an extensive literature search was performed to succinctly summarize the primary active ingredients and mechanisms of action of hand sanitizers, compare the effectiveness and compliance of gel and foam sanitizers, and predict whether alcohol and non-alcohol hand sanitizers would be effective against SARS-CoV-2.

Results

Most alcohol-based hand sanitizers are effective at inactivating enveloped viruses, including coronaviruses. With what is currently known in the literature, one may not confidently suggest one mode of hand sanitizing delivery over the other. When hand washing with soap and water is unavailable, a sufficient volume of sanitizer is necessary to ensure complete hand coverage, and compliance is critical for appropriate hand hygiene.

Conclusions

By extrapolating effectiveness of hand sanitizers on viruses of similar structure to SARS-CoV-2, this virus should be effectively inactivated with current hand hygiene products, though future research should attempt to determine this directly.

Efficacy of ethanol against viruses in hand disinfection

Ethanol is used worldwide in healthcare facilities for hand rubbing. It has been reported to have a stronger and broader virucidal activity compared with propanols. The aim of this review was to describe the spectrum of virucidal activity of ethanol in solution or as commercially available products. A systematic search was conducted. Studies were selected when they contained original data on reduction of viral infectivity from suspension tests (49 studies) and contaminated hands (17 studies). Ethanol at 80% was highly effective against all 21 tested, enveloped viruses within 30 s. Murine norovirus and adenovirus type 5 are usually inactivated by ethanol between 70% and 90% in 30 s whereas poliovirus type 1 was often found to be too resistant except for ethanol at 95% (all test viruses of EN 14476). Ethanol at 80% is unlikely to be sufficiently effective against poliovirus, calicivirus (FCV), polyomavirus, hepatitis A virus (HAV) and foot-and-mouth disease virus (FMDV). The spectrum of virucidal activity of ethanol at 95%, however, covers the majority of clinically relevant viruses. Additional acids can substantially improve the virucidal activity of ethanol at lower concentrations against, e.g. poliovirus, FCV, polyomavirus and FMDV although selected viruses such as HAV may still be too resistant. The selection of a suitable virucidal hand rub should be based on the viruses most prevalent in a unit and on the user acceptability of the product under frequent-use conditions.

Making change easy: A peer-to-peer guide on transitioning to new hand hygiene products

This report summarizes our experiences planning and implementing the transition to a new commercial line of hand hygiene products and their dispensing systems in a large academic health care facility in Toronto, Canada. Our lessons learned are organized into a practical guide made available in 2 different formats: this article and an illustrated peer-to-peer guide (http://www.baycrest.org/wp-content/uploads/HCE-PROG-HH_HighQuality.pdf).

Factors influencing field testing of alcohol-based hand rubs

BACKGROUND

According to the World Health Organization guidelines, field tests, in the context of a bid for the supply of alcohol-based hand rubs, should take into account climatic region, test period, products already in use, and type of use (hygienic or surgical) when assessing tolerance. This laborious method is often contested.

OBJECTIVE

To conduct a post hoc analysis of the data of a large bid, including 5 factors, to validate the relevance of their inclusion.

METHODS

For the purposes of the bid, products were compared in terms of the 4 World Health Organization tolerance criteria (appearance, intactness, moisture content, sensation) during product testing and were separated into groups on the basis of the studied factors. The post hoc analysis method included (1) comparison of the mean before-and-after difference based on the self-evaluation of the skin with the 4 World Health Organization tolerance criteria, between climatic regions, periods, products in use, test product, and the type of use; (2) generalized linear models, taking into account all studied factors.

RESULTS

The analysis included data for 1,925 pairs of professionals. The means of the differences observed were independently and significantly associated with the test period (P<.001), the hygienic or surgical use (P=.010 to .041, not significant for appearance), the product already in use (significant for appearance P=.021), and the test product (P<.001). The association with climatic region was found to be significant only in the nonadjusted analysis.

CONCLUSION

The type of use, the test period, and the product in use should be taken into account when designing field tests of alcohol-based hand rubs.