Efficacy of alcohol-based hand rubs against human adenovirus on contaminated hands

Viruses significantly contribute to outbreaks in healthcare facilities, primarily through direct or indirect hand contact. Consequently, hand disinfection using hygienic hand rubs is a pivotal measure for preventing nosocomial virus infections in medical environments. In 2024, the EN 17430 standard was introduced as the first method to evaluate the virucidal efficacy of hand disinfectants under practical conditions. The new method offers an advantage over suspension tests (e.g., EN 14476) by enabling the assessment of hand rubs using human volunteers. This study aims to compare the results of these two methods by investigating the in vivo efficacy of various ethanol formulations and two commercially available alcohol mixtures against human adenovirus type 5 (AdV-5).

The in vivo efficacy of pure Ethanol formulations in concentrations from 60% to 97% and two alcohol mixtures (M1: 45 % ethanol and 18 % 1-propanol; M2: 45% 2-propanol and 30% 1-propanol) were evaluated on the hands of 5 or 20 volunteers, utilizing a cross-over study design based on EN 17430.

With the different ethanol formulations increasing reduction factors with higher alcohol concentrations were detected. Of the two alcohol-containing mixtures, only M1 demonstrated efficacy based on the requirements of EN 17430, the second formulation M2, however, narrowly failed effectiveness.

In conclusion, results from suspension tests with AdV-5 were not directly transferable to those obtained with the alcohol formulations tested under practical conditions as per EN 17430.