Quantitation of Risk Reduction of E. coli Transmission after Using Antimicrobial Hand Soap (original) (raw)

Effects of various hand hygiene regimes on removal and/or destruction of Escherichia coli on hands

Food Service Technology, 2005

Various hand hygiene techniques have been recommended by sanitarians. In the USA, the National Restaurant Association (NRA) ServSafe ® program guidelines include a recommended hand washing regime. The ServSafe regime was compared to rinsing with warm and cool water and no washing/rinsing for bare hands and gloves after exposure to ground beef (approximately 10 6 cells/g) or liquid solution (approximately 10 6 cells/mL) contaminated with an ampicillin-resistant Escherichia coli JM 109 strain . The efficacy of alcohol-based hand sanitizers to replace hand washing was also evaluated. ServSafe, warm water rinse and cool water rinse reduced E. coli cells on hands by 98.0, 64.4 and 42.8% log 10 cfu/mL, resulting in < 1, 1.4, and 2,1 log 10 cfu/ mL E. coli on hands, respectively, from 3.6 log 10 cfu/mL on unwashed hands. When vinyl food service gloves were worn during the hand washing treatments, gloves retained more bacteria than when only hands were rinsed or washed. From 2.9 to 3.4 log 10 cfu/mL remained on hands when ethanol-based sanitizers were used instead of hand washing. Of all hand washing treatments tested in these experiments, the US NRA recommended method was most effective ( P < 0.05) in removing E. coli from hands and the levels remaining after this method were below the threshold of detection ( < 10 cfu/hand).

Washing with contaminated bar soap is unlikely to transfer bacteria

Epidemiology and Infection, 1988

Recent reports of the isolation of microorganisms from used soap bars have raised the concern that bacteria may be transferred from contaminated soap bars during handwashing. Since only one study addressing this question has been published, we developed an additional procedure to test this concern. In our new method prewashed and softened commercial deodorant soap bars (0-8% triclocarban) not active against Gram-negative bacteria were inoculated with Escherichia coli and Pseudomonas aeruginosa to give mean total survival levels of 4-4 x 10 5 c.f.u. per bar which was 70-fold higher than those reported on used soap bars. Sixteen panelists were instructed to wash with the inoculated bars using their normal handwashing procedure. After washing, none of the 16 panelists had detectable levels of either test bacterium on their hands. Thus, the results obtained using our new method were in complete agreement with those obtained with the previously published method even though the two methods differ in a number of procedural aspects. These findings, along with other published reports, show that little hazard exists in routine handwashing with previously used soap bars and support the frequent use of soap and water for handwashing to prevent the spread of disease.

Assessment of Microbial Quality and Antibacterial Activity of Commonly used Hand Washes Published by Society for Advancement of Sciences

Hands are the highways to the transmission and spread of pathogens that causes diseases, food borne illnesses and nosocomial infections. Hand washing is the act of cleansing the hands with water or another liquid, with or without the use of soap or other detergents, to ensure proper hand hygiene. To determine the microbiological quality and the antibacterial property and dilution effects on activity of hand wash, seven brands of hand washes were evaluated using susceptibility test by agar well diffusion, minimum inhibitory dilution and time kill test. This was done by assessing different dilutions of the hand washes against standardized 1.5x108 cells of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Results showed that all the hand washes were sterile and all the brands had some level of antibacterial activity. The hand washes were more active on Staphylococcus aureus and Escherichia coli than on Pseudomonas aeruginosa. Activity decreased with dilution as neat and 2-1 dilutions gave better results compared to 2-2, 10-1 and 10-2. Hib hand wash killed all test organisms when exposed for 2, 5 and 10 minutes and at neat and 2-1 dilutions but not at 2-2, 10-1 and 10-2. Rev and Pan hand washes though are sterile, were least active in all the tests. The minimum inhibitory dilution and minimum bactericidal dilution for most of the hand wash was at neat concentration. The time kill test showed that the effect of the hand wash was highest at 5 and 10 minutes and at neat (undiluted) for all the test organisms. It is advised that the dilution of hand washes a common practice in most eateries must stop as these products are not active when diluted, hands should be washed for five to ten minutes for maximum hand hygiene. Key words: Antibacterial Activity, Food Borne Illnesses, Hand Hygiene, Microbiological Quality, Nosocomial Infections and Pathogens.

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

PLOS ONE, 2017

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

Microbiological Evaluation of the Efficacy of Soapy Water to Clean Hands: A Randomized, Non-Inferiority Field Trial

The American Journal of Tropical Medicine and Hygiene, 2014

We conducted a randomized, non-inferiority field trial in urban Dhaka, Bangladesh among mothers to compare microbial efficacy of soapy water (30 g powdered detergent in 1.5 L water) with bar soap and water alone. Fieldworkers collected hand rinse samples before and after the following washing regimens: scrubbing with soapy water for 15 and 30 seconds; scrubbing with bar soap for 15 and 30 seconds; and scrubbing with water alone for 15 seconds. Soapy water and bar soap removed thermotolerant coliforms similarly after washing for 15 seconds (mean log 10 reduction = 0.7 colony-forming units [CFU], P 0.001 for soapy water; mean log 10 reduction = 0.6 CFU, P = 0.001 for bar soap). Increasing scrubbing time to 30 seconds did not improve removal (P 0.05). Scrubbing hands with water alone also reduced thermotolerant coliforms (mean log 10 reduction = 0.3 CFU, P = 0.046) but was less efficacious than scrubbing hands with soapy water. Soapy water is an inexpensive and microbiologically effective cleansing agent to improve handwashing among households with vulnerable children.

Quantitative Microbial Risk Assessment of Antibacterial Hand Hygiene Products on Risk of Shigellosis

Journal of Food Protection, 2014

There are conflicting reports on whether antibacterial hand hygiene products are more effective than nonantibacterial products in reducing bacteria on hands and preventing disease. This research used new laboratory data, together with simulation techniques, to compare the ability of nonantibacterial and antibacterial products to reduce shigellosis risk. One hundred sixty-three subjects were used to compare five different hand treatments: two nonantibacterial products and three antibacterial products, i.e., 0.46% triclosan, 4% chlorhexidine gluconate, or 62% ethyl alcohol. Hands were inoculated with 5.5 to 6 log CFU Shigella; the simulated food handlers then washed their hands with one of the five products before handling melon balls. Each simulation scenario represented an event in which 100 people would be exposed to Shigella from melon balls that had been handled by food workers with Shigella on their hands. Analysis of experimental data showed that the two nonantibacterial treatm...

Efficacy of Instant Hand Sanitizers against Foodborne Pathogens Compared with Hand Washing with Soap and Water in Food Preparation Settings: A Systematic Review

Journal of food protection, 2016

Hands can be a vector for transmitting pathogenic microorganisms to foodstuffs and drinks, and to the mouths of susceptible hosts. Hand washing is the primary barrier to prevent transmission of enteric pathogens via cross-contamination from infected persons. Conventional hand washing involves the use of water, soap, and friction to remove dirt and microorganisms. The availability of hand sanitizing products for use when water and soap are unavailable has increased in recent years. The aim of this systematic review was to collate scientific information on the efficacy of hand sanitizers compared with washing hands with soap and water for the removal of foodborne pathogens from the hands of food handlers. An extensive literature search was carried out using three electronic databases: Web of Science, Scopus, and PubMed. Twenty-eight scientific publications were ultimately included in the review. Analysis of this literature revealed various limitations in the scientific information owi...