Abstract
Various rub-in hand disinfectants have been developed for hygienic and surgical hand disinfection. In this study, the immediate and persistent effects of 1.0 w/v% and 0.5 w/v% chlorhexidine gluconate/ethanol preparations (1.0% CHG–AL and 0.5% CHG–AL, respectively) on the numbers of bacteria on the hands of 41 experienced nurses were investigated using the glove juice method. 1.0% CHG–AL and 0.5% CHG–AL exhibited significantly greater efficacy than 0.2 w/v% benzalkonium chloride/ethanol preparation immediately and 3 hours after disinfection (p≤0.05, Fisher's exact test). The most common microorganisms isolated in this study were coagulase-negative staphylococci (CNS) and Bacillus spp. Immediately after and 3 hours after disinfection with 1.0% CHG–AL, the counts of CNS were significantly reduced by 180– and 170–fold, respectively, compared with those seen before disinfection (p≤0.05, Student's t-test). Immediately after and 3 hours after disinfection with 0.5% CHG–AL, the counts of CNS were significantly reduced by 513–fold, compared with those detected before disinfection (p≤0.05, Student's t-test). Immediately after and 3 hours after disinfection with 1.0% CHG–AL, the counts of Bacillus spp. were significantly reduced by more than eleven- and seven-fold, compared with those observed before disinfection, respectively, but 0.5% CHG–AL had no effect on the counts of these bacteria. In comparisons between the two timepoints, neither 1.0% CHG–AL nor 0.5% CHG–AL exhibited significant log10 reduction factors for the numbers of total microorganisms, CNS, or isolated Bacillus spp., indicating that both disinfectants had strong persistent effects (p≤0.05, Student's t-test). Therefore, the disinfection efficacy of 1.0% CHG–AL was superior to that of 0.5% CHG–AL, based on the significantly more effective action against Bacillus spp.
