Persistence of the Antibacterial and Antiviral Effects after Skin Cleansing ~A New Approach to Suppress the Contact Infection~

Abstract

IntroductionThere have been several global pandemics (e.g., severe acute respiratory syndrome ［SARS］ , influenza, Zika, and Ebola) in the recent past 1,2) . With the spread of SARS-CoV-2 infection, hygiene awareness among consumers has increased 3) . Examples of effective ways to protect oneself from pathogens in daily life include handwashing, gargling, and wearing a mask 4,5) . Handwashing is particularly important for protection against infections because it prevents pathogens from entering the body through the mouth and eyes 6,7) . Previous studies have shown that handwashing with soap, rather than water alone, effectively eliminates pathogens 8−11) . Among the ingredients used in handwashing soaps, fatty acid salts have strong antibacterial effects 12−15) . Previous studies have focused exclusively on the antibacterial effect achieved immediately upon handwashing, yet its persistence is of major relevance to suppressing the risk of contact infection 16,17) . The latter remains understudied, and there is limited knowledge on methods for assessing it and on the active ingredients that drive persistence.