Glycerol content within the WHO ethanol-based handrub formulation: balancing tolerability with antimicrobial efficacy

Mayra Gonçalves MeneguetiEmail author View ORCID ID profile,
Ana Maria Laus,
Márcia Aparecida Ciol,
Maria Auxiliadora-Martins,
Anibal Basile-Filho,
Elucir Gir,
Daniela Pires,
Didier Pittet and
Fernando Bellissimo-Rodrigues

Antimicrobial Resistance & Infection Control20198:109

https://doi.org/10.1186/s13756-019-0553-z

Received: 27 April 2019
Accepted: 6 June 2019
Published: 24 June 2019

Abstract

Background

The World Health Organization (WHO) ethanol-based handrub (EBHR) formulation contains 1.45% glycerol as an emollient to protect healthcare workers’ (HCWs) skin against dryness and dermatitis. However, glycerol seems to negatively affect the antimicrobial efficacy of alcohols. In addition, the minimal concentration of glycerol required to protect hands remain unknown. We aim to evaluate the tolerance of HCWs to the WHO EBHR formulation using different concentrations of glycerol in a tropical climate healthcare setting.

Methods

We conducted a cluster-randomized, double-blind, crossover study among 40 HCWs from an intensive care unit of a tertiary-care hospital in Brazil, from June 1st to September 30, 2017. We tested the WHO EBHR original formulation containing 1.45% glycerol against three other concentrations (0, 0.5, and 0.75%). HCWs used one formulation at a time for seven working days during their routine practice and then had their hands evaluated by an external observer using the WHO scale for visual inspection. Participants also used a WHO self-evaluation tool to rate their own skin condition. We used a generalized estimating equations of the logit type to compare differences between the tolerability to different formulations.

Results

According to the independent observation, participants had 2.4 times (95%CI: 1.12–5.15) more chance of having a skin condition considered good when they used the 0.5% compared to the 1.45% glycerol formulation. For the self-evaluation scale, participants were likely to have a worst evaluation (OR: 0.23, 95%CI: 0.11–0.49) when they used the preparation without glycerol compared to the WHO standard formulation (1.45%), and there were no differences between the other formulations used.

Conclusion

In a tropical climate setting, the WHO-modified EBHR formulation containing 0.5% glycerol led to better ratings of skin tolerance than the original formulation, and, therefore, may offer the best balance between skin tolerance and antimicrobial efficacy.