In healthcare, alcohol-based hand rubs (ABHR) are used up to 100 times daily as most important measure for preventing infections. Consequently, it is a hot topic how this affects skin healthiness and subsequently compliance as skin diseases are the most common cause of absenteeism among healthcare workers. The skin microbiome plays an important role in ensuring healthy skin. Consequently, the aim of the study was to show how ABHR influencing the skin microbiome.
20 participants were enrolled. They received a liquid, ABHR (active ingredient 75 g propan-2-ol/100 g) and were instructed to disinfect their hands at least ten times on weekdays and five times on weekends over 28 days. Samples were taken using the “glove juice method” according to ASTM E2755-22 before the first disinfection, after 3, and 24 hours, on days 14, 28, and 3 days after last disinfection. Quantification of 16S rRNA for determination of the total bacterial count and Gram differentiation was performed using real-time PCR. Illumina V3 chemistry was used for sequencing. To compare the Shannon index between groups and samples, a Kruskal-Wallis H test was calculated with ANOVA (p <= 0.05).
20 participants completed the study, and all planned samples were collected. The molecular biological analyses showed an increase of the diversity until day 14, which then stabilizes. Overall, gram-negative bacteria are in the background (approx. 30 %). Diversity decreases until day 28 for all bacteria. This continues after the end of use until day 3. However, the difference is still statistically significant different compared to pre-values.
We conclude that we were able demonstrating the effect of the ABHR on the skin microbiome with the study design. We saw that the skin microbiome adapts quickly within two weeks to the product use and the influence is significantly reduced subsequently. This means that at least with the preparation used in our study, good (microbiological) skin tolerance can be postulated without negative impact on the skin microbiome. In addition, no skin incompatibilities from the participants were reported during the study.