Methods.Interventions included warm water with plain soap, cold water with plain soap, warm water with antibacterial soap, antiseptic hand wipes, alcohol-based handrub, and a control involving no Intervention. All interventions were evaluated for mean reduction in colony-forming units (CFUs) under 2 contamination protocols: “whole hand” and “palmar surface.” Results were analyzed according to a Bayesian approach, by using hierarchical models adjusted for multiple observations.
Results.Under the whole-hand protocol, the greatest adjusted mean reductions were achieved by warm water with plain soap (2.14 log10 CFU/mL [95% credible interval (Cri), 1.74-2.54 log10 CFU/mL]), cold water with plain soap (1.88 log10 CFU/mL [95% Cri, 1.48-2.28 log10 CFU/mL), and warm water with antibacterial soap (1.51 log10 CFU/mL [95% Cri, 1.12-1.91 logu, CFU/mL]), followed by antiseptic hand wipes (0.57 log10 CFU/mL [95% Cri, 0.17-0.96 log10 CFU/mL]). Alcohol-based handrub (0.06 log10 CFU/mL [95% CrI, -0.34 to 0.45 log10 CFU/mL]) was equivalent to no Intervention. Under the palmar surface protocol, warm water with plain soap, cold water with plain soap, and warm water with antibacterial soap again yielded the greatest mean reductions, followed by antiseptic hand wipes (26.6, 26.6, 26.6, and 21.9 CFUs per plate, respectively), when compared with alcohol-based handrub. Hypothenar (odds ratio, 10.98 [95% Cri, 1.96-37.65]) and thenar (odds ratio, 6.99 [95% Cri, 1.25-23.41]) surfaces were more likely than fingertips to remain heavily contaminated after handwashing.