Hand Contamination Research Articles

The Use of Electric Toilet Seats with Water Spray Is Efficacious in Maintaining Hand Hygiene in Experimental Model.

A simulation experiment was conducted to examine hand contamination from wiping the buttocks after the use and non-use of an electric toilet seat with water spray. A model of the buttocks was smeared with artificial diarrheal feces containing Serratia marcescens, and wiped by the participants wearing disposable gloves with 4 sheets of toilet paper after the use and non-use of the water spray of an electric toilet seat. Subsequently, the presence of S. marcescens on the surface of the gloves was quantified. After using the water spray, the mean count±standard deviation of S. marcescens was 0.067±0.249 colony-forming units (cfu)/glove, and it was 4,275±6,069 cfu/glove when water spray was not used. The cfu of S. marcescens was significantly lower when the water spray was used (p<0.00001) prior to wiping the artificial diarrheal feces. This result supports the effectiveness of water spray to prevent defecation-related hand contamination.

A microbiological assessment of sterile surgical helmet systems using particle counts and culture plates: recommendations for safe use whilst scrubbing

Infection occurs in 2-4% of arthroplasty cases, and identifying potential sources of infection can help to reduce infection rates. The aim of this study was to identify the impact and potential for the contamination of hands and gowns whilst scrubbing using sterile surgical helmet systems (SSHSs). A colony-forming unit (cfu) is a pathogenic particle of 0.5-5 μm. Standard arthroplasty hoods and SSHSs, with and without the fan switched on, were tested for a 3-min exposure (to represent scrubbing time) on three subjects and a mannequin with concurrent particle counts and culture plates. All SSHSs were positive for Gram-positive cocci, with a mean colony count of 410cfu/m2. Background counts were lower for laminar flow areas [mean 0.7 particles/m3; 95% confidence interval (CI) 0-1.4] than scrub areas (mean 131.5 particles/m3; 95% CI 123.5-137.9; P=0.0003). However, neither grew any bacteria with a 2-min exposure. The background count increased 3.7 times with the fan switched on (total P=0.004, cfu P=0.047), and all helmets had positive cultures (mean 36cfu/m2). There were no positive cultures with the standard arthroplasty hood or the SSHS with the fan switched off. In laminar flow areas, all cultures were negative and particle counts were low. Sterile gloves and gowns can be contaminated when scrubbing with the SSHS fan switched on. It is recommended that the fan should remain switched off when scrubbing until the hood and gown are in place, ideally in a laminar flow environment.

Staphylococcus aureus and Escherichia coli levels on the hands of theatre staff in three hospitals in Johannesburg, South Africa, before and after handwashing

Hand hygiene is a fundamental component of infection control. Hand contamination with Staphylococcus aureus and Escherichia coli may contribute to infections. To assess the effectiveness of different handwashing methods in reducing the levels of bacterial flora, especially S. aureus and E. coli, on the hands of theatre staff. A cross-sectional study was conducted among 70 staff in surgical theatres of three randomly chosen hospitals in Johannesburg, South Africa. Samples were taken before and after handwashing using the modified glove juice method and the fingernail press technique. Standard microbiological techniques were used to identify bacteria. Descriptive statistics and non-parametric analysis were used to compare the differences between hospitals and to determine the effects of handwashing on microbial flora and skin irritation. S. aureus organisms were isolated in the prewash samples of 29 (41%) and in the postwash samples of 20 (29%) workers. Of the 29 with positive prewash cultures, 19 (65.5%) showed decreased postwash counts, while 10 (34.5%) showed no change or increased counts. Four workers with a negative prewash count had a positive postwash count. No statistical differences were found between postwash counts categorised by the type of cleansing formula used and the washing technique. E. coli organisms were identified in the prewash count of the fingertip press of one worker. Almost half of the theatre staff carried S. aureus isolates on their hands prior to handwashing and approximately one-third after handwashing. Closer monitoring of handwashing techniques should be introduced.

Study on the protective effect of an innovative cow milk-based product against some human skin-bacterial pathogens

There is a growing interest related to the possible use of some components of cow milk that behave as immunomodulators, exert biological activity, and have anti-inflammatory factors. The aims of the study were: i) to investigate the chemical composition and antioxidant activity of Podolian cow milk; ii) to test the efficacy of some hand soaps supplemented with different percentage of cow milk compared to placebo; iii) to evaluate the antibacterial activity of milk added to soap. Antioxidant activity of Podolian milk resulted in mean 97.03% and 52.09% utilizing 2,2’-azinobis 3-ethylbenzthiazoline-6-acid and 2,2-diphenyl-1-picrylhydrazyl methods, respectively. The efficacy test showed that the most effective soap was obtained adding 5% of Podolian milk. For this soap, total counting bacterial test evidenced the highest reduction of bacterial hand contamination assessed by 98%.

How long is enough? Identification of product dry-time as a primary driver of alcohol-based hand rub efficacy

BackgroundThe World Health Organization has called for the development of improved methodologies to evaluate alcohol-based handrub (ABHR) efficacy, including evaluation at “short application times and volumes that reflect actual use in healthcare facilities”. The objective of this study was to investigate variables influencing ABHR efficacy, under test conditions reflective of clinical use.MethodsThe test product (60% V/V 2-propanol) was evaluated according to a modified EN 1500 methodology, where application volumes of 1 mL, 2 mL, and 3 mL were rubbed until dry. Statistical analyses were performed to investigate the relative influences of product volume, hand size, and product dry-time on efficacy, and hand size and hand contamination on product dry-time.ResultsMean log10 reduction factors (SD) were 1.99 (0.66), 2.96 (0.84) and 3.28 (0.96); and mean dry-times (SD) were 24 s (7 s), 50 s (14 s), and 67 s (20 s) at application volumes of 1 mL, 2 mL, and 3 mL, respectively (p ≤ 0.030). When data were examined at the individual volunteer level, there was a statistically significant correlation between dry-time and log reduction factor (p < 0.0001), independent of application volume. There was also a statistically significant correlation between hand surface area and dry-times (p = 0.047), but no correlation between hand surface area and efficacy (p = 0.698).ConclusionsWhen keeping other variables such as alcohol type and concentration constant, product dry-time appears to be the primary driver of ABHR efficacy suggesting that dosing should be customized to each individual and focus on achieving a product dry-time delivering adequate efficacy.

Bactericidal and Virucidal Activity of Povidone-Iodine and Chlorhexidine Gluconate Cleansers in an In Vivo Hand Hygiene Clinical Simulation Study.

IntroductionStandard in vitro and in vivo tests help demonstrate efficacy of hand hygiene products; however, there is no standard in vivo test method for viruses. We investigated the bactericidal and virucidal efficacy of povidone-iodine (PVP-I) 7.5% scalp and skin cleanser, chlorhexidine gluconate (CHG) 4% hand cleanser and the reference hand wash (soft soap) in 15 healthy volunteers following European Standard EN1499 (hygienic hand wash test method for bacteria), which was adapted for virucidal testing.MethodsSeparate test series were performed for bactericidal (Escherichia coli) and virucidal [murine norovirus (MNV)] testing. After pre-washing and artificial contamination of hands with test organisms, volunteers underwent testing with 3 and 5 mL of each product for contact times of 15, 30 and 60 s according to a Latin-square randomization. The number of test organisms released from fingertips into sampling fluids was assessed before and after hand washing and mean log10 reduction factor (RF) was calculated. RFs (test-reference) were compared using a Wilcoxon–Wilcox multiple comparisons test per EN1499; efficacy was concluded if p ≤ 0.01.ResultsPVP-I 7.5% and CHG 4% cleansers both passed EN1499 requirements against E. coli, with statistically significantly greater (p ≤ 0.01) mean log10 RFs compared with reference soft soap across all tests (PVP-I: 4.09–5.27; CHG: 4.12–5.22; soap: 2.75–3.11). The experimental design using EN1499 was applicable to testing with MNV as discriminatory and reproducible results were generated. Mean log10 RFs of MNV were statistically significantly greater for PVP-I (1.57–2.57) compared with soft soap (1.24–1.62), while mean log10 RFs with CHG (0.90–1.34) were lower than for soft soap across all tests.ConclusionPVP-I 7.5% cleanser showed superior efficacy against MNV compared to soft soap and CHG 4% cleanser, while both PVP-I and CHG were superior to soft soap against E. coli. The experimental set-up may be applicable to future testing for antiviral hand washes.FundingMundipharma Manufacturing Pte Ltd.Plain Language SummaryPlain language summary available for this article.

High time-resolution simulation of E. coli on hands reveals large variation in microbial exposures amongst Vietnamese farmers using human excreta for agriculture

Infectious disease transmission is frequently mediated by the environment, where people's movements through and interactions with the environment dictate risks of infection and/or illness. Capturing these interactions, and quantifying their importance, offers important insights into effective interventions. In this study, we capture high time-resolution activity data for twenty-five Vietnamese farmers during collection and land application of human excreta for agriculture. Although human excreta use improves productivity, the use increases risks of enteric infections for both farmers and end users. In our study, the activity data are integrated with environmental microbial sampling data into a stochastic-mechanistic simulation of E. coli contamination on hands and E. coli ingested. Results from the study include frequent and variable contact rates for farmers' hands (from 34 to 1344 objects contacted per hour per hand), including highly variable hand-to-mouth contact rates (from 0 to 9 contacts per hour per hand). The frequency of hand-to-mouth contacts was substantially lower than the widely-used frequency previously reported for U.S. Office Workers. Environmental microbial contamination data highlighted ubiquitous E. coli contamination in the environment, including excreta, hands, toilet pit, handheld tools, soils, surfaces, and water. Results from the simulation suggest dynamic changes in E. coli contamination on hands, and wide variation in hand contamination and E. coli ingested amongst the farmers studied. Sensitivity analysis suggests that E. coli contamination on hands and ingested doses are most influenced by contamination of handheld tools, excreta, and the toilet pit as well as by frequency of hand-to-mouth contacts. The study findings are especially relevant given the context: no farmers reported adequate storage time of human excreta, and personal protective mask availability did not prevent hand-to-mouth contacts. Integrating high time-resolution activity data into exposure assessments highlights variation in exposures amongst farmers, and offers greater insight into effective interventions and their potential impacts.

The bacterial contamination of food handlers hands in Wad madani city restaurants, Sudan

Background: Food handlers may cross-contaminate raw and processed food stuffs as well as inadequately cook and store foods. These contributory factors are due to a lack of food hygiene awareness or implementation.Methods: Study was conducted between (October to December 2017), 100 samples were collected randomly from hands of food handlers working in restaurants of Wad Madani city. A sterile quality swabs were used to collecting the samples from handlers after screened the hand of handler particularly around the fingers and palm. The swab was immediately sealed and transported to Al-bagea medical center laboratory for examination. One hundred questionnaires were designed to obtain information about food handlers knowledge and their personal hygiene. The data was analyzed by (SPSS v16th) system.Results: The contaminated hands of food handlers by bacteria was 87%, the minimum colony forming unit (CFU) was (10×106 cfu/ml), 70% of handlers were educated and 55% of handlers were working in restaurants more than 5 years.Conclusions: The study showed high level of education of food handlers and may be aware of the need for personal hygiene, they do not comprehend crucial aspects of hygiene such as cleaning of work surfaces and washing their hands by water and soap, so we need deep messages for health education of food handlers.

A historical review of the study on biology of the dwarf tapeworm Hymenolepis nana

The purpose of the research: to submit a review of national and foreign literature on biological research of Hymenolepis nana. Materials and methods. Papers on morphology and biology of H. nana (starting from the first discovery of H. nana in 1851 by German parasitologist T. Bilharz until the present moment) written by 26 native and 11 foreign authors served as research material. When analyzing the literature, special attention was paid to the results of the morphological study and development cycle of H. nana taking into account the developmental stages of cestodes. Results and discussion. Specific data on morphology of H. nana and pictures of scolex and proglottids of the dwarf tapeworm using scanning electronic microscopy were provided. Structure of H. nana eggs was described in detail. Most papers are dedicated to the study of biological features of development. Sometimes, H. nana is reproduced by budding (passing through the following development cycle: megalospheres, metamers, invagination, scolexogenesis, larval cysts). Eggs were found in animals’ feces 17-18 days after infestation. H. nana lives in human body for several years, and sometimes 20-38 years. Issues related to the species identity of H. nana and H. fraternal, and mechanisms of transmission and prevalence of infection are discussed. Prevalence of hymenolepiasis in different countries depends not on climate conditions but on the degree of population density. Contamination of hands is an important factor influencing the frequency of hymenolepiasis autoinvasion in patients. The role of rodents as a source of H. nana infection is not essential.

Escherichia coli Contamination across Multiple Environmental Compartments (Soil, Hands, Drinking Water, and Handwashing Water) in Urban Harare: Correlations and Risk Factors.

.Escherichia coli pathotypes (i.e., enteropathogenic and enterotoxigenic) have been identified among the pathogens most responsible for moderate-to-severe diarrhea in low- and middle-income countries (LMICs). Pathogenic E. coli are transmitted from infected human or animal feces to new susceptible hosts via environmental reservoirs such as hands, water, and soil. Commensal E. coli, which includes nonpathogenic E. coli strains, are widely used as fecal bacteria indicator, with their presence associated with increased likelihood of enteric pathogens and/or diarrheal disease. In this study, we investigated E. coli contamination in environmental reservoirs within households (N = 142) in high-population density communities of Harare, Zimbabwe. We further assessed the interconnectedness of the environmental compartments by investigating associations between, and household-level risk factors for, E. coli contamination. From the data we collected, the source and risk factors for E. coli contamination are not readily apparent. One notable exception is the presence of running tap water on the household plot, which is associated with significantly less E. coli contamination of drinking water, handwashing water, and hands after handwashing. In addition, E. coli levels on hands after washing are significantly associated with handwashing water contamination, hand contamination before washing, and diarrhea incidence. Finally, we observed that animal ownership increases E. coli contamination in soil, and E. coli in soil are correlated with contamination on hands before washing. This study highlights the complexity of E. coli contamination in household environments within LMICs. More, larger, studies are needed to better identify sources and exposure pathways of E. coli—and enteric pathogens generally—to identify effective interventions.

High Hand Contamination Rates During Norovirus Outbreaks in Long-Term Care Facilities.

We examined norovirus contamination on hands of ill patients during 12 norovirus outbreaks in 12 long-term care facilities (LTCFs). The higher frequency and norovirus titers on hands of residents compared to hands of heathcare workers highlights the importance of adhering to appropriate hand hygiene practices during norovirus outbreaks in LTCFs. Infect Control Hosp Epidemiol 2018;39:219-221.

Bacterial contamination of hands and anterior nares of health care professionals attending ICu at a tertiary care hospital in South India

Bacterial contamination of hands and anterior nares of health care professionals attending ICu at a tertiary care hospital in South India

BACTERIAL CONTAMINATION OF HANDS OF MEDICAL INTERNS AND UNDERGRADUATE STUDENTS

Objective: Cross-transmission by the hands of health-care workers is considered the main route of spread of nosocomial infections. Awareness among medical students and interns about the importance of hand hygiene practices and facilities for its adherence can play a major role in reducing disease transmission. The objectives of the present study were: (1) To determine the level and type of microbial contamination present on the hands of medical students and interns from a teaching hospital of Mangalore, Karnataka, and (2) to evaluate the relationship between hand contamination and knowledge, attitude, and practices of hand hygiene.Methods: Swabs were obtained from the dominant hand and the skin surface beneath the rings of participants during their routine work hours. Laboratory analysis was carried out within one hour of collection of samples. The participants were asked to fill a questionnaire on hand hygiene. Descriptive statistics and analysis was done by Chi-square test.Results: Of the 70 study participants, 35 (50%) were medical undergraduate students and 35 (50%) were medical interns. The contamination rate was higher among the undergraduates (91.4% [32/35]) compared to interns (77.1% [27/35]). 38 (54%) participants hands were contaminated with Staphylococcus aureus, of which 17 (44.7%) were methicillin-resistant S. aureus. Although overall knowledge status about hand hygiene was good, concepts about certain key elements in hand hygiene were not clearly understood by the participants. Knowledge about alcohol-based hand rubs was not up to the mark. The level of knowledge was found to be similar between UGs and interns and between the genders. Wearing ring while handling patients had an influence on hand contamination.Conclusions: Although the overall knowledge about hand hygiene was good, very few participants knew that hand hygiene after exposure to immediate surroundings of patient can prevent cross-transmission. Health-care workers may unknowingly carry antibiotic-resistant bacteria on their hands. Being unaware of this fact may have serious repercussions as the students and interns may serve as a medium for the spread of nosocomial infections.

Bacterial contamination of white coats and hands of healthcare workers at mansoura university children’s hospital, Mansoura-Egypt

Background: Transmission of hospital acquired infections (HAIs) may be associated with contamination of healthcare workers’ (HCWs) hands and white coats.Objective: The purpose of this study was to clarify the role of HCWs’ white coats in transmitting HAIs and to determine the association between bacterial contamination of HCWs’ hands and white coats.Methods: A total of 154 HCWs were enrolled in the study; different samples were taken from their hands and white coats. Samples were processed and both microbiological and biochemical characterization of the isolates were done using standard microbiological protocols.Results: Up to 65.6% of hands and 61% of coats of HCWs were contaminated by microorganisms. Staphylococcus aureus was the most commonly isolated organisms from both hands and coats of HCWs (29.2%, 27.3% respectively) followed by MRSA (22.1%, 24.7% respectively).Conclusions: The risk for contamination of hands and coats of HCWs is high in different clinical settings. In order to reduce the rate of HAIs, a strict dress protocol should be set into play to prevent cross contamination between HCWs and patients.Keywords: contamination, HCWs, coat, hand, Staphylococcus aureus, MRSA. Contamination bacterienne de manteaux blancs et de mains de soins de sante a l'hopital pour enfants de l'universite mansoura, Mansoura-EgypteContexte: La transmission des infectionsObjectif: Le but de cette étude était de déterminer l'étendue, le type et l'association entre la contamination bactérienne des mains des travailleurs de la santé et les blouses blanches.Méthodes: Au total, 154 travailleurs de la santé ont été inclus dans l'étude; différents échantillons ont été pris de leurs mains et des manteaux blancs. Les échantillons ont été traités et la caractérisation microbiologique et biochimique des isolats a été effectuée en utilisant des protocoles microbiologiques standard.Résultats: Jusqu'à 65,6% des mains et 61% des couches de TS ont été contaminées par des micro-organismes. Le Staphylococcus aureus était le plus souvent isolé des deux mains et des deux sexes (29,2%, 27,3%), suivi par le SARM (22,1%, 24,7% respectivement).Conclusions: Le risque de contamination des mains et des couches de TS est élevé dans différents contextes cliniques. Afin de réduire le taux d'IASS, un protocole vestimentaire strict devrait être mis en place pour prévenir la contamination croisée entre les travailleurs de la santé et les patients.Mots clés: contamination, agents de santé, manteau, main, Staphylococcus aureus, SARM

Enhancing handwashing frequency and technique of primary caregivers in Harare, Zimbabwe: A cluster-randomized controlled trial using behavioral and microbial outcomes

RationaleConsistent hand hygiene prevents diarrheal and respiratory diseases, but it is often not practiced. The disease burden is highest in low-income settings, which need effective interventions to promote domestic handwashing. To date, most handwashing campaigns have focused on promoting frequent handwashing at key times, whereas specifically promoting handwashing techniques proven to be effective in removing microbes has been confined to healthcare settings. MethodsWe used a cluster-randomized, factorial, controlled trial to test the effects of two handwashing interventions on the behavior of primary caregivers in Harare, Zimbabwe. One intervention targeted caregivers directly, and the other targeted them through their children. Outcome measures were surveyed at baseline and six weeks’ follow-up and included observed handwashing frequency and technique and fecal hand contamination before and after handwashing. ResultsCombining the direct and indirect interventions resulted in observed handwashing with soap at 28% of critical handwashing times, while the corresponding figure for the non-intervention control was 5%. Observed handwashing technique, measured as the number of correctly performed handwashing steps, increased to an average of 4.2, while the control averaged 3.4 steps. Demonstrated handwashing technique increased to a mean of 6.8 steps; the control averaged 5.2 steps. No statistically significant group differences in fecal hand contamination before or after handwashing were detected. ConclusionsThe results provide strong evidence that the campaign successfully improved handwashing frequency and technique. It shows that the population-tailored design, based on social-cognitive theory, provides effective means for developing powerful interventions for handwashing behavior change. We did not find evidence that children acted as strong agents of handwashing behavior change. The fact that the microbial effectiveness of handwashing did not improve despite strong improvements in handwashing technique calls for critical evaluation of existing handwashing recommendations. The aim of future handwashing campaigns should be to promote both frequent and effective handwashing.

Modified gloves: A chance for the prevention of nosocomial infections

Non-sterile gloves primarily serve as a barrier protection for health care workers (HCWs). However, pathogens may often contaminate the skin of HCWs during glove removal; therefore, pathogens may be further transmitted and cause nosocomial infections. A field study was conducted comparing contamination rates when using standard gloves or a new modified product equipped with an additional flap (doffing aid) for easier removal. Gloves were removed after bathing gloved hands in an artificial fluorescent lotion. The number of contamination spots was then visually examined using ultraviolet light. There were 317 individuals who participated in this study: 146 participants (104 nurses and 42 physicians) used standard gloves, whereas 171 participants (118 nurses and 53 physicians) used the modified product. Use of the modified gloves instead of the standard product (15.8% vs 73.3%, respectively; P < .001) and being a physician rather than a nurse (29.5% vs 47.7%, respectively; P = .003) were the only independent risk factors for reduction of contamination. This study shows that the modified product could, at least in vitro, significantly reduce the rate of hand and wrist contamination during removal compared with standard gloves. By this, it may significantly improve the overall quality of patient care when used on the wards directly at the patient's site.

Contamination of firefighter personal protective equipment and skin and the effectiveness of decontamination procedures

ABSTRACTFirefighters' skin may be exposed to chemicals via permeation/penetration of combustion byproducts through or around personal protective equipment (PPE) or from the cross-transfer of contaminants on PPE to the skin. Additionally, volatile contaminants can evaporate from PPE following a response and be inhaled by firefighters. Using polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) as respective markers for non-volatile and volatile substances, we investigated the contamination of firefighters' turnout gear and skin following controlled residential fire responses. Participants were grouped into three crews of twelve firefighters. Each crew was deployed to a fire scenario (one per day, four total) and then paired up to complete six fireground job assignments. Wipe sampling of the exterior of the turnout gear was conducted pre- and post-fire. Wipe samples were also collected from a subset of the gear after field decontamination. VOCs off-gassing from gear were also measured pre-fire, post-fire, and post-decon. Wipe sampling of the firefighters' hands and neck was conducted pre- and post-fire. Additional wipes were collected after cleaning neck skin. PAH levels on turnout gear increased after each response and were greatest for gear worn by firefighters assigned to fire attack and to search and rescue activities. Field decontamination using dish soap, water, and scrubbing was able to reduce PAH contamination on turnout jackets by a median of 85%. Off-gassing VOC levels increased post-fire and then decreased 17–36 min later regardless of whether field decontamination was performed. Median post-fire PAH levels on the neck were near or below the limit of detection (< 24 micrograms per square meter [µg/m2]) for all positions. For firefighters assigned to attack, search, and outside ventilation, the 75th percentile values on the neck were 152, 71.7, and 39.3 µg/m2, respectively. Firefighters assigned to attack and search had higher post-fire median hand contamination (135 and 226 µg/m2, respectively) than other positions (< 10.5 µg/m2). Cleansing wipes were able to reduce PAH contamination on neck skin by a median of 54%.

Controlling a possible outbreak of Candida auris infection: lessons learnt from multiple interventions

Multidrug-resistant Candida auris infection has been reported from five continents in recent years. The prevalence of C.auris invasive infection has been estimated at 5.3% for intensive-care-acquired candidaemia in India. The transmission of the organism between the patients and from environment to patients is rapid. To understand the intra-hospital dynamics of C.auris transmission and to determine the possible interventions to prevent its spread. Surveillance of intensive care units was carried out to assess patient colonization, environmental contamination and hand carriage of the yeast among healthcare workers. Interventions including chlorhexidine washing of patients and decontamination of environmental surfaces with stabilized hydrogen peroxide disinfectant (Ecoshield) were undertaken. We further evaluated the effectiveness of frequently used disinfectants in the hospital against C.auris on various inanimate surfaces, and its persistence on hospital fabrics. Three cases of C.auris bloodstream infection were detected over a period of three months. Many patients admitted at the same time, in the same area, were colonized by C.auris. Surveillance detected C.auris contamination of environmental surfaces and hands of healthcare workers. Interventions such as chlorhexidine washing and appropriate use of disinfectants could eradicate C.auris from patients and hospital environment. The frequently used disinfectants in our hospital and current hand hygiene practices were efficient against C.auris if proper contact time and procedures were followed. Evaluation of possible persistence of C.auris on dry fabrics showed that they can persist for up to seven days.

Erratum to "A model of exposure to rotavirus from nondietary ingestion iterated by simulated intermittent contacts." By T.R. Julian, R.A. Canales, J.O. Leckie, and A.B. Boehm, in Risk Analysis, 29(5):617-622.

Article: Risk Analysis 2009; 29: 617–632

Contamination of Fresh Produce by Microbial Indicators on Farms and in Packing Facilities: Elucidation of Environmental Routes.

To improve food safety on farms, it is critical to quantify the impact of environmental microbial contamination sources on fresh produce. However, studies are hampered by difficulties achieving study designs with powered sample sizes to elucidate relationships between environmental and produce contamination. Our goal was to quantify, in the agricultural production environment, the relationship between microbial contamination on hands, soil, and water and contamination on fresh produce. In 11 farms and packing facilities in northern Mexico, we applied a matched study design: composite samples (n = 636, equivalent to 11,046 units) of produce rinses were matched to water, soil, and worker hand rinses during two growing seasons. Microbial indicators (coliforms, Escherichia coli, Enterococcus spp., and somatic coliphage) were quantified from composite samples. Statistical measures of association and correlations were calculated through Spearman's correlation, linear regression, and logistic regression models. The concentrations of all microbial indicators were positively correlated between produce and hands (ρ range, 0.41 to 0.75; P < 0.01). When E. coli was present on hands, the handled produce was nine times more likely to contain E. coli (P < 0.05). Similarly, when coliphage was present on hands, the handled produce was eight times more likely to contain coliphage (P < 0.05). There were relatively low concentrations of indicators in soil and water samples, and a few sporadic significant associations were observed between contamination of soil and water and contamination of produce. This methodology provides a foundation for future field studies, and results highlight the need for interventions surrounding farmworker hygiene and sanitation to reduce microbial contamination of farmworkers' hands.IMPORTANCE This study of the relationships between microbes on produce and in the farm environment can be used to support the design of targeted interventions to prevent or reduce microbial contamination of fresh produce with associated reductions in foodborne illness.