Quantitation of Risk Reduction of E. coli Transmission after Using Antimicrobial Hand Soap

Abstract

Handwashing with soap is an effective and economical means to reduce the likelihood of Escherichia coli infection from indirect contact with contaminated surfaces during food preparation. The purpose of this study was to conduct a quantitative microbial risk assessment (QMRA) to evaluate the risk of infection from indirect contact with fomites contaminated with E. coli after hand washing with antimicrobial hand soaps. A Monte Carlo simulation was done with a total of 10,000 simulations to compare the effectiveness of two antimicrobial and one control (non-antimicrobial) bar soaps in reducing the exposure and infection risk compared to no hand washing. The numbers of E. coli on several fomites commonly found in household kitchens, as well as the transfer rates between fomites and onto fingertips, were collected from the literature and experimental data. The sponsor company provided the E. coli survival on hands after washing with antimicrobial and control soaps. A number of scenarios were evaluated at two different exposure doses (high and low). Exposure scenarios included transfer of E. coli between meat-to-cutting board surface-to-hands, meat-to-knife surface-to-hands, and from a countertop surface-to-hands, kitchen sponge-to-hands, hand towel-to-hands, and dishcloth-to-hands. Results showed that the risks of illness after washing with the control soap was reduced approximately 5-fold compared to no handwashing. Washing with antimicrobial soap reduced the risk of E. coli infection by an average of about 40-fold compared with no handwashing. The antimicrobial soaps ranged from 3 to 32 times more effective than the non-antimicrobial soap, depending on the specific exposure scenario. Importance: The Centers for Disease Control and Prevention indicate the yearly incidence rate of Shiga Toxin producing E. coli infections is about 1.7/100,000, with about 10% of cases leading to life-threatening hemolytic uremic syndrome and 3–5% leading to death. Our findings confirm handwashing with soap reduces the risks associated with indirect transmission of E. coli infection from contact with fomites during food preparation. Further, in these exposure scenarios, antimicrobial soaps were more effective overall than the non-antimicrobial soap in reducing exposure to E. coli and risk of infection.

Microbiological Contamination in Different Food Service Units Associated with Food Handling

“…Our data also revealed that Canteens and Retirement Homes/Day Care Centers had a high proportion of samples taken from hands of food handlers classified as "unsatisfactory", denoting less adherence to handwashing practices. Indeed, it has been reported that a reduction occurs in counts of Enterobacteriaceae, including E. coli after hand washing, particularly when food handlers use antimicrobial hand soap [11,20]. Additionally, the evaluation of hygienic patterns of the hands of manipulators in different food units also showed that more than 10% of positive samples for S. aureus were found in Fishmongers (14.3%), Schools/Kindergartens (12.1%) and Pastry/Bakery establishments (11.8%).…”

“…Indeed, a pathogenic microorganism can remain viable in cutting boards and food contact surfaces [6][7][8] demanding the rigorous cleaning and disinfection of kitchen utensils, equipment and surfaces [9,10]. Hands of food handlers have also been considered an important determinant of microbiological contamination of food and washing hands plays a valuable role in preventing the transmission of foodborne illnesses [4,11,12]. Staphylococcus aureus colonizes the nasopharynx of asymptomatic carriers leading to the contamination of the hands of food handlers [13,14].…”

Efficacy of Removing Bacteria and Organic Dirt from Hands—A Study Based on Bioluminescence Measurements for Evaluation of Hand Hygiene When Cooking

“…Washing hands with water and soap reduced the risk of foodborne illnesses during multiple contamination scenarios (i.e., transfer of E. coli from cutting board surface to hands, kitchen sponge to hands, etc.) by approximately 5 times compared to no handwashing [3] and reduced Enterococcus concentrations from farmworkers' hands (1.6 log 10 reduction) [22].…”

“…In 2019, The European Food Safety Authority (EFSA) reported 5175 foodborne outbreaks that affected 53,383 people; inadequate consumer hygiene practices in the household being the most commonly reported source (41.3%) [2]. Foodborne diseases are preventable, and proper hand hygiene has been acknowledged as one of the most simple and adequate measures to prevent or reduce the infection rate with foodborne pathogens and the number of cases of foodborne illnesses, which usually occur through inefficient hand hygiene, cross-contamination, and transmission of certain bacteria and viruses [3][4][5][6][7][8][9][10].…”

Scalila Surprise Hand Soap: The Herbal Soap Creation of Breadfruit Leaf Solution for Routine Hand Washing for Children

“…c. Position The product "Scalila Surprise Hand Soap" is positioned as a practical hand soap containing antibacterial which attracts children's attention to wash their hands regularly with soap because of its unique and cute shape [8].…”