was lower in the 4 % chlorhexidine gluconate group ( 10.5 % , p = 0.006 ) , in the 7.5 % povidone-iodine group ( 18.7 % , p = 0.043 ) , and in the alcohol-based hand rub group ( 21.1 % , p = 0.048 ) compared to the group washing hands with plain soap and water ( 50 % ) .