title: Handwashing and Ebola virus disease outbreaks: A randomized comparison of soap, hand sanitizer, and 0.05% chlorine solutions on the inactivation and removal of model organisms Phi6 and E. coli from hands and persistence in rinse water.
abstract: To prevent Ebola transmission, frequent handwashing is recommended in Ebola Treatment Units and communities. However, little is known about which handwashing protocol is most efficacious. We evaluated six handwashing protocols (soap and water, alcohol-based hand sanitizer (ABHS), and 0.05% sodium dichloroisocyanurate, high-test hypochlorite, and stabilized and non-stabilized sodium hypochlorite solutions) for 1) efficacy of handwashing on the removal and inactivation of non-pathogenic model organisms and, 2) persistence of organisms in rinse water. Model organisms E. coli and bacteriophage Phi6 were used to evaluate handwashing with and without organic load added to simulate bodily fluids. Hands were inoculated with test organisms, washed, and rinsed using a glove juice method to retrieve remaining organisms. Impact was estimated by comparing the log reduction in organisms after handwashing to the log reduction without handwashing. Rinse water was collected to test for persistence of organisms. Handwashing resulted in a 1.94-3.01 log reduction in E. coli concentration without, and 2.18-3.34 with, soil load; and a 2.44-3.06 log reduction in Phi6 without, and 2.71-3.69 with, soil load. HTH performed most consistently well, with significantly greater log reductions than other handwashing protocols in three models. However, the magnitude of handwashing efficacy differences was small, suggesting protocols are similarly efficacious. Rinse water demonstrated a 0.28-4.77 log reduction in remaining E. coli without, and 0.21-4.49 with, soil load and a 1.26-2.02 log reduction in Phi6 without, and 1.30-2.20 with, soil load. Chlorine resulted in significantly less persistence of E. coli in both conditions and Phi6 without soil load in rinse water (p<0.001). Thus, chlorine-based methods may offer a benefit of reducing persistence in rinse water. We recommend responders use the most practical handwashing method to ensure hand hygiene in Ebola contexts, considering the potential benefit of chlorine-based methods in rinse water persistence.
authors.affiliation: Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts, United States of America.
authors.forename: Marlene K
authors.identifier: http://orcid.org/0000-0002-6476-0450
authors.initials: MK
authors.lastname: Wolfe
authors.affiliation: Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts, United States of America.
authors.forename: Karin
authors.initials: K
authors.lastname: Gallandat
authors.affiliation: Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts, United States of America.
authors.forename: Kyle
authors.initials: K
authors.lastname: Daniels
authors.affiliation: Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts, United States of America.
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Desmarais
authors.affiliation: Department of Dermatology, Brigham and Women's Hospital, Boston, Massachusetts, United States of America.
authors.forename: Pamela
authors.initials: P
authors.lastname: Scheinman
authors.affiliation: Department of Civil and Environmental Engineering, Tufts University, Medford, Massachusetts, United States of America.
authors.forename: Daniele
authors.initials: D
authors.lastname: Lantagne
mesh_terms: D000293:Adolescent; D017126:Bacteriophage phi 6 / Q000187:drug effects* / Q000302:isolation & purification; D002713:Chlorine; D004196:Disease Outbreaks / Q000517:prevention & control*; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification; D005260:Female; D006235:Hand Disinfection / Q000379:methods*; D064548:Hand Sanitizers; D019142:Hemorrhagic Fever, Ebola; D006801:Humans; D008297:Male; D012915:Soaps; D014871:Water Microbiology; D055815:Young Adult
chemical_list: D064548:Hand Sanitizers; D012915:Soaps; D002713:Chlorine