Hand hygiene is broadly recognized as a critical intervention in reducing the spread of disease-causing pathogens in both professional and personal uses. In this study, the impact of antibacterial (AB) or nonantibacterial soaps on the removal and postwash transfer of E. coli following the handling of raw poultry was assessed. Baseline bacterial contamination ranged between 107 and 109 CFU per hand. Hands were washed for 30 s in 40°C ± 2°C tap water using 2 mL of AB soap (0.5% and 1.0% Chloroxylenol, 0.5% Benzalkonium Chloride, or 4.0% Chlorhexidine Gluconate), non-AB soap (cosmetic/plain soap), or water. Postwash, water, and non-AB soap had a mean 3.63 and 3.65 Log10 reduction of E. coli on hands. AB treatments had a mean 4.19–4.35 Log10 reduction. Rinse water had mean bacterial counts of 8.62 and 8.88 Log10 CFU/mL for non-AB soap and water and 5.37–6.90 Log10 CFU/mL for AB treatments. Bacterial transfer was assessed by following the test subject’s handling of a sterile polymer knife handle for 30 s postwash. E. coli transfer ranged from 263 to 903 CFU/handle for AB soaps and 1572 or 1709 CFU/handle for water and non-AB soap. Differences between AB and non-AB treatments were statistically significant (p < 0.0001) for hands and rinse water. Differences in transfer from hands to knife handle were not statistically significant (p = 0.139). Combined, these data highlight significant differences in the performance of AB soaps relative to non-AB soaps in a food handling environment-specific usage example and provide an unexplored assessment of the bactericidal vs. removal effects of AB vs. non-AB soaps on bacteria removed from the hands. These data reinforce the importance of hand hygiene, provide new details on the differences between AB vs. non-AB soaps, and highlight potential differences to inform food handling environment operators and public health personnel on how these products may impact food safety.

Abstract Background Surface contamination via hands plays an important role in pathogen spread in public spaces. This study aimed to identify frequently touched surfaces and evaluate the spread of a surrogate virus in a hotel lobby. Methods In a working hotel lobby, observation was performed (30 hours) to identify the surfaces and objects touched. An entry doorknob and first floor elevator button were seeded with a bacteriophage (Phi-X174) tracer; 4 hours later 25 surfaces were swabbed to determine tracer distribution and contamination levels. Results A total of 324 individuals performed 627 touches over 13 different fomites in the hotel lobby. The elevator button and front desk counter were the most frequently touched (32 and 22% of all touches respectively), with 55% of individuals touching the elevator button and 79% touching either the elevator button, the front desk counter, or both. More than half (56%) touched 2 or more surfaces; there were 314 interactions between surfaces. Touches from the elevator button to other surfaces (92 interactions) and from other surfaces to the elevator button (41) made up 42% of all interactions and connected the elevator button to 9 other fomites including doors, countertops, seating, a credit card reader and a hand sanitizer pump. From two seeded sites, the tracer spread to 13 surfaces over 4 hours. The most contaminated surfaces were tables, counter tops and door handles. Other contaminated objects were the luggage cart handle, sanitizer pump, and computer equipment. Conclusions Surfaces in the hotel lobby were frequently touched and highly interconnected, resulting in extensive spread of surface contamination in as little as 4 hours. This study demonstrates the importance of hands in distributing contamination between shared surfaces and highlights the need for hand and surface hygiene interventions to disrupt the journey of the germ in public settings. Key messages • Frequently touched surfaces in public spaces are interconnected. • Interconnection of people via touched surfaces drives the spread of pathogens in a public setting.

Abstract Background In public spaces, the importance of surface contamination in the transmission of respiratory viruses has been debated. This study aimed to compare the spread of a surrogate virus in a hotel lobby before and after a Targeted Hygiene intervention, and to quantify the reduction in risk of infection from respiratory diseases. Methods In a working hotel lobby, 13 fomites were seeded with a bacteriophage (Phi-X174) tracer at 8 am; 4 hours later 25 surfaces were swabbed to determine baseline tracer distribution and contamination levels. This was then repeated with the addition of a pre-determined Targeted Hygiene intervention performed 2 hours after seeding. Four replicate baseline and intervention trials were conducted, and data were compared for statistically significant (p < 0.05) differences. Risk of infection was estimated via Quantitative Microbial Risk Assessment modelling. Results Following the Targeted Hygiene intervention there was a significant reduction in the spread of the tracer (contamination of 13% of sampled surfaces vs. 50% at baseline). Tracer concentrations (PFU/site) were significantly lower overall (9.1E+02 PFU vs. 5.8E+04 PFU, p < 0.0001), including surfaces that had not been disinfected. Our model estimates that the risk of infection from common respiratory viruses via surface transmission was reduced by 97%. Conclusions Extensive spread of surface contamination can occur in a hotel lobby in as little as 4 hours. This study demonstrates how a Targeted Hygiene intervention can significantly disrupt the journey of the germ, even on surfaces not cleaned and disinfected, resulting in a consequent reduction of infection risk via surface transmission of common respiratory infections. This demonstrates the value of carrying out effective hygiene interventions to those managing commercial spaces. Key messages • Targeted Hygiene can significantly reduce the spread of respiratory pathogens via surface transmission, providing a means for facilities managers to achieve high standards using a targeted approach. • The Targeted Hygiene approach can significantly reduce the risk of infection from common respiratory viruses via surface transmission in public spaces.

Tap water quality concerns and advertisements often drive increased bottled water consumption, especially in communities with historical tap water quality problems (e.g., Nogales, Arizona). The study objective was to assess contamination of municipal tap and bottled water in Nogales, Arizona. Bottled (sealed, open/partially consumed bottles, and reusable containers for vended water) and tap water samples were collected from 30 homes and analyzed for chemical and microbial contaminants. Fisher exact tests and Wilcoxon rank sum tests were used to compare proportions of positive samples and contaminant concentrations between tap and bottled water samples. While none of the chemical contaminants were above MCLs, there were statistically significantly greater concentrations and proportions of positive samples for some contaminants, including arsenic, in tap vs. bottled water. E. coli concentrations were >0 CFU/100mL in some unsealed bottled water samples but not for sealed bottles. This study demonstrates that 1) the measured concentrations in tap and bottled water likely pose low risks, as they are below the MCLs, 2) more education in this community on hygiene maintenance of refillable or opened bottled water containers is needed, and 3) using tap water over bottled water is advantageous due to likely lower E. coli risk and lower cost.

Numerous studies are published on the benefits of electric hand dryersvspaper towels (PT) for drying hands after washing. Data are conflicting and lacking key variables needed to assess infection risks. We provide a rapid scoping review on hand-drying methods relative to hygiene and health risks. Controlled vocabulary terms and keywords were used to search PubMed (1946-2018) and Embase (1947-2018). Multiple researchers independently screened abstracts for relevance using predetermined criteria and created a quality assessment scoring system for relative study comparisons. Of 293 papers, 23 were included in the final analysis. Five studies did not compare multiple methods; however, 2 generally favoured electric dryers (ED); 7 preferred PT; and 9 had mixed or statistically insignificant results (among these, 3 contained scenarios favourable to ED, 4 had results supporting PT, and the remaining studies had broadly conflicting results). Results were mixed among and within studies and many lacked consistent design or statistical analysis. The breadth of data does not favour one method as being more hygienic. However, some authors extended generalizable recommendations without sufficient scientific evidence. The use of tools in quantitative microbial risk assessment is suggested to evaluate health exposure potentials and risks relative to hand-drying methods. We found no data to support any human health claims associated with hand-drying methods. Inconclusive and conflicting results represent data gaps preventing the advancement of hand-drying policy or practice recommendations.

First responders may have high SARS-CoV-2 infection risks due to working with potentially infected patients in enclosed spaces. The study objective was to estimate infection risks per transport for first responders and quantify how first responder use of N95 respirators and patient use of cloth masks can reduce these risks. A model was developed for two Scenarios: an ambulance transport with a patient actively emitting a virus in small aerosols that could lead to airborne transmission (Scenario 1) and a subsequent transport with the same respirator or mask use conditions, an uninfected patient; and remaining airborne SARS-CoV-2 and contaminated surfaces due to aerosol deposition from the previous transport (Scenario 2). A compartmental Monte Carlo simulation model was used to estimate the dispersion and deposition of SARS-CoV-2 and subsequent infection risks for first responders, accounting for variability and uncertainty in input parameters (i.e., transport duration, transfer efficiencies, SARS-CoV-2 emission rates from infected patients, etc.). Infection risk distributions and changes in concentration on hands and surfaces over time were estimated across sub-Scenarios of first responder respirator use and patient cloth mask use. For Scenario 1, predicted mean infection risks were reduced by 69%, 48%, and 85% from a baseline risk (no respirators or face masks used) of 2.9 x 10(-2) +/- 3.4 x 10(-2) when simulated first responders wore respirators, the patient wore a cloth mask, and when first responders and the patient wore respirators or a cloth mask, respectively. For Scenario 2, infection risk reductions for these same Scenarios were 69%, 50%, and 85%, respectively (baseline risk of 7.2 x 10(-3) +/- 1.0 x 10(-2)). While aerosol transmission routes contributed more to viral dose in Scenario 1, our simulations demonstrate the ability of face masks worn by patients to additionally reduce surface transmission by reducing viral deposition on surfaces. Based on these simulations, we recommend the patient wear a face mask and first responders wear respirators, when possible, and disinfection should prioritize high use equipment.

Viral infections are an occupational health concern for office workers and employers. The objectives of this study were to estimate rotavirus, rhinovirus, and influenza A virus infection risks in an office setting and quantify infection risk reductions for two hygiene interventions. In the first intervention, research staff used an ethanol-based spray disinfectant to clean high-touch non-porous surfaces in a shared office space. The second intervention included surface disinfection and also provided workers with alcohol-based hand sanitizer gel and hand sanitizing wipes to promote hand hygiene. Expected changes in surface concentrations due to these interventions were calculated. Human exposure and dose were simulated using a validated, steady-state model incorporated into a Monte Carlo framework. Stochastic inputs representing human behavior, pathogen transfer efficiency, and pathogen fate were utilized, in addition to a mixed distribution that accounted for surface concentrations above and below a limit of detection. Dose-response curves were then used to estimate infection risk. Estimates of percent risk reduction using mean values from baseline and surface disinfection simulations for rotavirus, rhinovirus, and influenza A infection risk were 14.5%, 16.1%, and 32.9%, respectively. For interventions with both surface disinfection and the promotion of personal hand hygiene, reductions based on mean values of infection risk were 58.9%, 60.8%, and 87.8%, respectively. This study demonstrated that surface disinfection and the use of personal hand hygiene products can help decrease virus infection risk in communal offices. Additionally, a variance-based sensitivity analysis revealed a greater relative importance of surface concentrations, assumptions of relevant exposure routes, and inputs representing human behavior in estimating risk reductions.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has increased demands for surgical and respirator masks for healthcare workers (HCWs) and other frontline staff. The debate over the importance of airborne transmission of SARS-CoV-2 continues, but air and laboratory studies have shown that SARS-CoV-2 is viable for >12 h in aerosols [1Chia K. Coleman K. Tan Y. Ong S. Gum M. Lau S. et al.Detection of air and surface contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in hospital rooms of infected patients.medRxiv. 2020; https://doi.org/10.1101/2020.03.29.20046557Crossref Google Scholar, 2Fears A. Klimstra W. Duprex P. Hartman A. Weaver S. Plante K. et al.Comparative dynamic aerosol efficiencies of three emergent coronaviruses and the unusual persistence of SARS-CoV-2 in aerosol suspensions.medRxiv. 2020; https://doi.org/10.1101/2020.04.13.20063784Crossref PubMed Scopus (0) Google Scholar, 3Ong S.W.X. Tan Y.K. Chia P.Y. Lee T.H. Ng O.T. Wong M.S.Y. et al.Air, surface environmental, and personal protective equipment contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a symptomatic patient.JAMA. 2020; https://doi.org/10.1001/jama.2020.3227Crossref PubMed Scopus (1564) Google Scholar]. Low sampling volumes, location of air outlet fan and potential virus damage during sampling may explain the variability in detection of SARS-CoV-2 [1Chia K. Coleman K. Tan Y. Ong S. Gum M. Lau S. et al.Detection of air and surface contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in hospital rooms of infected patients.medRxiv. 2020; https://doi.org/10.1101/2020.03.29.20046557Crossref Google Scholar,3Ong S.W.X. Tan Y.K. Chia P.Y. Lee T.H. Ng O.T. Wong M.S.Y. et al.Air, surface environmental, and personal protective equipment contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a symptomatic patient.JAMA. 2020; https://doi.org/10.1001/jama.2020.3227Crossref PubMed Scopus (1564) Google Scholar]. A limited supply of masks creates a risk for the exposure of HCWs to SARS-CoV-2. Non-traditional materials are widely recommended for public use (source control) and have been considered in place of regulated masks in health care, especially in social care settings. While various materials are effective for filtering large droplets, aerosols generated from sneezing, coughing and aerosol-generating procedures may pass more readily through materials or leakage points [4Weber A. Willeke K. Marchioni R. Myojo T. Mckay R. Donnelly J. et al.Aerosol penetration and leakage characteristics of masks used in the health care industry.Am J Infect Control. 1993; 21: 167-173Abstract Full Text PDF PubMed Scopus (134) Google Scholar]. Few data exist on the efficacy of filtration, and no quantitative modelling of efficacies to reduce the risk of infection is currently available. A probabilistic model was developed to estimate the risk of infection for short (30-s, brief patient check) and long (20-min, duration required for patient intubation) inhalation exposure scenarios. These included situations in a room with a patient with coronavirus disease 2019 (COVID-19) when no mask was worn; when an FFP2 (N95) respirator, FFP3 (N99) respirator or surgical mask was worn; or when a non-traditional material mask (silk, tea towel, vacuum cleaner bag, pillowcase, antimicrobial pillowcase, cotton mix, 100% cotton T-shirt, linen or scarf) was worn. Inhaled viral dose was estimated using published concentrations (RNA/m3) of SARS-CoV-2 for >4- and 1–4-μm droplets measured in a hospital setting [1Chia K. Coleman K. Tan Y. Ong S. Gum M. Lau S. et al.Detection of air and surface contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in hospital rooms of infected patients.medRxiv. 2020; https://doi.org/10.1101/2020.03.29.20046557Crossref Google Scholar]. Ranges from reported concentration data originating from a symptomatic and an asymptomatic patient were used to calculate minimum and maximum values for randomly sampled uniform distributions [1Chia K. Coleman K. Tan Y. Ong S. Gum M. Lau S. et al.Detection of air and surface contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in hospital rooms of infected patients.medRxiv. 2020; https://doi.org/10.1101/2020.03.29.20046557Crossref Google Scholar]. Viral exposures for these two size ranges were summed to estimate the total inhaled dose. Doses were estimated for three assumed infectious fractions of total detected viral RNA: 0.1%, 1% and 10%. Inhaled volumes (m3) were estimated using inhalation rates for men and women, where the 5th and 99th percentiles of inhalation rates offered the uniform distribution minimum and maximum, respectively [5U.S. Environmental Protection AgencyExposure factors handbook. US EPA, Washington, DC2011Google Scholar]. Filtration efficacies (fraction of total virus filtered out by the material) were used to model the reduction in viral inhalation exposure for each material type. Due to lack of particle-size-specific filtration efficacy data for these materials, it was assumed that filtration efficacy distributions were applicable to both particle size ranges. For each 10,000 combinations investigated, a filtration efficacy was sampled at random from a normal distribution, left- and right-truncated at 0 and 1, respectively. For surgical masks and non-traditional materials, means and standard deviations (SD) of efficacies were informed by MS2 filtration efficacies [6Davies A. Thompson K.A. Giri K. Kafatos G. Walker J. Bennett A. Testing the efficacy of homemade masks: would they protect in an influenza pandemic?.Disaster Med Public Health Prep. 2013; 7: 413-418Crossref PubMed Scopus (400) Google Scholar]. Mean efficacies of 95% and 99% were assumed for FFP2 and FFP3 respirators, respectively. SDs were provided by Rengasamy et al. (2009), where larger SDs of two manufacturer versions were chosen as a conservative risk approach [7Rengasamy S. Eimer B.C. Shaffer R.E. Comparison of nanoparticle filtration performance of NIOSH-approved and CE-marked particulate filtering facepiece respirators.Ann Occup Hyg. 2009; 53: 117-128Crossref PubMed Scopus (134) Google Scholar]. Data from SARS-CoV and human coronavirus 229E (HCoV-229E) dose–response curves were used to estimate a SARS-CoV-2 exact beta-Poisson curve [8Watanabe T. Bartrand T.A. Weir M.H. Omura T. Haas C.N. Development of a dose–response model for SARS coronavirus.Risk Anal. 2010; 30: 1129-1138Crossref PubMed Scopus (266) Google Scholar]. Based on current epidemiological knowledge, the infectivity of SARS-CoV-2 was assumed to lie between SARS-CoV and HCoV-229E. Pairs of bootstrapped alpha and beta values were used to estimate infection risk per dose. Comparing no protection (baseline) for 20-min and 30-s exposures, it was predicted that the mean risk of infection was reduced by 24–94% and 44–99% depending on the mask. Risk reductions decreased as exposure durations increased. The greatest reduction in estimated mean risk of infection was for FFP3 masks, which reduced baseline mean risks by 94% and 99% for 20-min and 30-s exposures, respectively (Figure 1). Of non-traditional materials, the vacuum cleaner bag resulted in the greatest reduction in mean risk of infection (20-min exposure 58%, 30-s exposure 83%), while scarves offered the lowest reduction (20-min exposure 24%, 30-s exposure 44%) (Figure 1). However, large variability in filtration, such as for silk or the tea towel, should be considered when comparing non-traditional mask materials (Figure 1). Limitations include not accounting for viral transfer from the hands to the mask during mask adjustments, and assuming that all masks were worn in the same way. Realistically, the fit of homemade masks is likely to be more variable than the fit of regulated masks. While the HCoV-229E data utilized for the dose–response curve were based on human data, the SARS-CoV dose–response data originated from an animal-feeding study [8Watanabe T. Bartrand T.A. Weir M.H. Omura T. Haas C.N. Development of a dose–response model for SARS coronavirus.Risk Anal. 2010; 30: 1129-1138Crossref PubMed Scopus (266) Google Scholar]. Future work includes updating the dose–response curve as data on SARS-CoV-2 emerge, and addressing the effects of design/fit on the risk of infection. This study demonstrated that some materials, such as vacuum cleaner bags, may be effective alternatives to reduce the risk of infection. While N95 masks (and similar respirators) are recommended for HCWs and others in close proximity to aerosol-generating procedures, alternative materials may be useful where there are shortages of personal protective equipment (PPE). This may be of particular relevance in low-resource settings where access to PPE is considerably more limited. None declared. A.M. Wilson was supported by the University of Arizona Foundation and the Hispanic Women's Corporation/Zuckerman Family Foundation Student Scholarship Award through the Mel and Enid Zuckerman College of Public Health, University of Arizona. M-F. King and C.J. Noakes were funded by the Engineering and Physical Sciences Research Council, UK: Healthcare Environment Control, Optimisation and Infection Risk Assessment (https://HECOIRA.leeds.ac.uk) (Grant Code: EP/P023312/1). M. López-García was funded by the Medical Research Council, UK (MR/N014855/1). J. Proctor was funded by EPSRC Centre for Doctoral Training in Fluid Dynamics at Leeds (Grant Code EP/L01615X/1). S.E. Abney was funded by a research assistantship from the US-Israel Binational Agricultural Research Development Fund and through a University of Arizona Graduate Access Scholarship.

Objectives:. Healthcare surfaces contribute to nosocomial disease transmission. Studies show that despite standard guidelines and practices for cleaning and disinfection, secondary infection spread among healthcare workers and patients is common in ICUs. Manual terminal cleaning practices in healthcare are subject to highly variable results due to differences in training, compliance, and other inherent complexities. Standard cleaning practices combined with no-touch disinfecting technologies, however, may significantly lower nosocomial infection rates. The objective of this study was to evaluate the efficacy of a whole-room, no-touch disinfection intervention to reduce the concentration and cross-contamination of surface bacteria when used in tandem with manual cleaning protocols. Design:. Bacterial tracers were seeded onto hospital room surfaces to quantitatively evaluate the efficacy of manual terminal cleaning practices alone and in tandem with a no-touch, whole-room atomization system. Cross-contamination potentials and labor efficiency were also evaluated. Subjects and Intervention:. Environmental service personnel cleaning efficacy was evaluated pre and post application of manual terminal cleaning protocols alone and in tandem with a whole-room atomization system with an United States Environmental Protection Agency-registered hospital-grade hypochlorous acid disinfectant. Setting:. The study was conducted in an unoccupied patient room at Banner University Medical Center in Tucson, AZ. The room was located in a newly constructed ICU suite. Measurements and Main Results:. Manual terminal cleaning averaged a 2.4 log10 reduction in seeded bacterial counts compared with a 4.9 average and up to a 6 log10 reduction with tandem cleaning. Cross-contamination among surfaces following terminal cleaning alone was documented in 50% of the samples compared with 0% with tandem cleaning, with the latter achieving a 64% improvement in manual labor efficiency. Conclusions:. The use of whole-room atomized disinfection with terminal cleaning protocols lowered manual labor times, improved disinfection outcomes, and eliminated the transfer of bacterial pathogens in healthcare environments.

Current microbial exposure models assume that microbial exchange follows a concentration gradient during hand-to-surface contacts. Our objectives were to evaluate this assumption using transfer efficiency experiments and to evaluate a model's ability to explain concentration changes using approximate Bayesian computation (ABC) on these experimental data. Experiments were conducted with two phages (MS2, Φ X174) simultaneously to study bidirectional transfer. Concentrations on the fingertip and surface were quantified before and after fingertip-to-surface contacts. Prior distributions for surface and fingertip swabbing efficiencies and transfer efficiency were used to estimate concentrations on the fingertip and surface post contact. To inform posterior distributions, Euclidean distances were calculated for predicted detectable concentrations (log 10 PFU cm −2 ) on the fingertip and surface post contact in comparison with experimental values. To demonstrate the usefulness of posterior distributions in calibrated model applications, posterior transfer efficiencies were used to estimate rotavirus infection risks for a fingertip-to-surface and subsequent fingertip-to-mouth contact. Experimental findings supported the transfer gradient assumption. Through ABC, the model explained concentration changes more consistently when concentrations on the fingertip and surface were similar. Future studies evaluating microbial transfer should consider accounting for differing fingertip-to-surface and surface-to-fingertip transfer efficiencies and extend this work for other microbial types.

Viral illnesses have a significant direct and indirect impact on the workplace that burdens employers with increased healthcare costs, low productivity, and absenteeism. Workers' direct contact with each other and contaminated surfaces contributes to the spread of viruses at work. This study quantifies the impact of an office wellness intervention (OWI) to reduce viral load in the workplace. The OWI includes the use of a spray disinfectant on high-touch surfaces and providing workers with alcohol-based hand sanitizer gel and hand sanitizing wipes along with user instructions. Viral transmission was monitored by applying an MS2 phage tracer to a door handle and the hand of a single volunteer participant. At the same time, a placebo inoculum was applied to the hands of four additional volunteers. The purpose was to evaluate the concentration of viruses on workers' hands and office surfaces before and after the OWI. Results showed that the OWI significantly reduced viable phage concentrations per surface area on participants' hands, shared fomites, and personal fomites (p = 0.0001) with an 85.4% average reduction. Reduction of virus concentrations on hands and fomites is expected to subsequently minimize the risk of infections from common enteric and respiratory pathogens. The surfaces identified as most contaminated were the refrigerator, drawer handles and sink faucets in the break room, along with pushbar on the main exit of the building, and the soap dispensers in the women's restroom. A comparison of contamination in different locations within the office showed that the break room and women's restrooms were the sites with the highest tracer counts. Results of this study can be used to inform quantitative microbial risk assessment (QMRA) models aimed at defining the relationship between surface contamination, pathogen exposure and the probability of disease that contributes to high healthcare costs, absenteeism, presenteeism, and loss of productivity in the workplace.

Background: Halting the spread of harmful microbes requires an understanding of their transmission via hands and fomites. Previous studies explored acute and long-term care environments but not outpatient clinics. Objectives of this study were to track microbial movement throughout an outpatient clinic and evaluate the impact of a disinfectant spray intervention targeting high-touch point surfaces. Methods: At the start of the clinic day, a harmless viral tracer was placed onto 2 fomites: a patient room door handle and front desk pen. Patient care, cleaning, and hand hygiene practices continued as usual. Facility fomites (n = 19), staff hands (n = 4), and patient hands (n = 3-4) were sampled after 2, 3.5, and 6 hours. Tracer concentrations at baseline (before intervention) were evaluated 6 hours after seeding. For the intervention trials, high-touch surfaces were cleaned 4 hours after seeding with an ethanol-based disinfectant and sampled 2 hours after cleaning. Results: At 2, 3.5, and 6 hours after seeding, virus was detected on all surfaces and hands sampled, with examination room door handles and nurses' station chair arms yielding the highest concentrations. Virus concentrations decreased by 94.1% after the disinfectant spray intervention (P= .001). Conclusions: Microbes spread quickly in an outpatient clinic, reaching maximum contamination levels 2 hours after inoculation, with the highest contamination on examination room door handles and nurses' station chairs. This study emphasizes the importance of targeted disinfection of high-touch surfaces. (C) 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc.

Nosocomial viral infections are an important cause of health care-acquired infections where fomites have a role in transmission. Using stochastic modeling to quantify the effects of surface disinfection practices on nosocomial pathogen exposures and infection risk can inform cleaning practices. The purpose of this study was to predict the effect of surface disinfection on viral infection risks and to determine needed viral reductions to achieve risk targets. Rotavirus, rhinovirus, and influenza A virus infection risks for two cases were modeled. Case 1 utilized a single fomite contact approach, while case 2 assumed 6 h of contact activities. A 94.1% viral reduction on surfaces and hands was measured following a single cleaning round using an Environmental Protection Agency (EPA)-registered disinfectant in an urgent care facility. This value was used to model the effect of a surface disinfection intervention on infection risk. Risk reductions for other surface-cleaning efficacies were also simulated. Surface reductions required to achieve risk probability targets were estimated. Under case 1 conditions, a 94.1% reduction in virus surface concentration reduced infection risks by 94.1%. Under case 2 conditions, a 94.1% reduction on surfaces resulted in median viral infection risks being reduced by 92.96 to 94.1% and an influenza A virus infection risk below one in a million. Surface concentration in the equations was highly correlated with dose and infection risk outputs. For rotavirus and rhinovirus, a > 99.99% viral surface reduction would be needed to achieve a one-in-a-million risk target. This study quantifies reductions of infection risk relative to surface disinfectant use and demonstrates that risk targets for low-infectious-dose organisms may be more challenging to achieve. IMPORTANCE It is known that the use of EPA-registered surface disinfectant sprays can reduce infection risk if used according to the manufacturer's instructions. However, there are currently no standards for health care environments related to contamination levels on surfaces. The significance of this research is in quantifying needed reductions to meet various risk targets using realistic viral concentrations on surfaces for health care environments. This research informs the design of cleaning protocols by demonstrating that multiple applications may be needed to reduce risk and by highlighting a need for more models exploring the relationship among microbial contamination of surfaces, patient and health care worker behaviors, and infection risks.

Background:Healthcare-associated infections are a significant threat to the safety of patients seeking medical care. Surface disinfection interventions have been evaluated in hospitals and workplaces but studies have not been published about other health care facilities such as outpatient or urgent care facilities. The purpose of this study is to evaluate a targeted surface disinfection intervention in an outpatient clinic with the use of a microbial tracer.

BACKGROUND:Study objectives were to track the transfer of microbes on soft surfaces in health care environments and determine the efficiency of an Environmental Protection Agency (EPA)-registered soft surface sanitizer in the health care environment. METHODS:Soft surfaces at 3 health care facilities were sampled for heterotrophic plate count (HPC) bacteria, Staphylococcus spp, Streptococcus pyogenes, and Escherichia coli followed by a tracer study with a virus surrogate seeded onto volunteer hands and commonly touched surfaces. The occurrence of microbial contaminants was determined along with microbial reductions using the soft surface sanitizer. Soft surfaces were swabbed pre- and postintervention. RESULTS:Tracer viruses spread to 20%-64% and 13%-41% of surfaces in long-term health care facilities and physicians' offices, respectively. Only 1 pathogen, methicillin-resistant Staphylococcus aureus, was recovered. The waiting room chairs had the highest concentration of HPC bacteria before disinfection (145.4 ± 443.3 colony forming units [cfu]/cm2), and the privacy curtains had the lowest (39.5 ± 84.2 cfu/cm2). Reductions of up to 98.5% were achieved with the sanitizer in health care settings and up to 99.99% under controlled laboratory conditions. CONCLUSIONS:Soft surfaces are involved in the spread of microbes throughout health care facilities. Routine application of an EPA-registered sanitizer for soft surfaces can help to reduce the microbial load and minimize exposure risks.

The quality of irrigation water drawn from surface water sources varies greatly. This is particularly true for waters that are subject to intermittent contamination events such as runoff from rainfall or direct entry of livestock upstream of use. Such pollution in irrigation systems increases the risk of food crop contamination and require adoption of best monitoring practices. Therefore, this study aimed to define optimal strategies for monitoring irrigation water quality. Following the analysis of 1357 irrigation water samples for Escherichia coil, total coliforms, and physical and chemical parameters, the following key irrigation water collection approaches are suggested: 1) explore up to 950m upstream to ensure no major contamination or outfalls exists; 2) collect samples before 12:00 p.m. local time; 3) collect samples at the surface of the water at any point across the canal where safe access is available; and 4) composite five samples and perform a single E. coil assay. These recommendations comprehensively consider the results as well as sampling costs, personnel effort, and current scientific knowledge of water quality characterization. These strategies will help to better characterize risks from microbial pathogen contamination in irrigation waters in the Southwest United States and aid in risk reduction practices for agricultural water use in regions with similar water quality, climate, and canal construction. (C) 2017 Elsevier B.V. All rights reserved.

Background: To our knowledge, no studies to date demonstrate potential spread of microbes during actual emergency medical service (EMS) activities. Our study introduces a novel approach to identification of contributors to EMS environment contamination and development of infection control strategies, using a bacteriophage surrogate for pathogenic organisms.Methods: Bacteriophage FX174 was used to trace cross-contamination and evaluate current disinfection practices and a hydrogen peroxide (H2O2) wipe intervention within emergency response vehicles. Prior to EMS calls, 2 surfaces were seeded with FX174. On call completion, EMS vehicle and equipment surfaces were sampled before decontamination, after decontamination per current practices, and after implementation of the intervention.Results: Current decontamination practices did not significantly reduce viral loads on surfaces (P = .3113), but H2O2 wipe intervention did (P = .0065). Bacteriophage spread to 56% (27/48) of sites and was reduced to 54% (26/48) and 40% (19/48) with current decontamination practices and intervention practices, respectively.Conclusion: Results suggest firefighters' hands were the main vehicles of microbial transfer. Current practices were not consistently applied or standardized and minimally reduced prevalence and quantity of microbial contamination on EMS surfaces. Although use of a consistent protocol of H2O2 wipes significantly reduced percent prevalence and concentration of viruses, training and promotion of surface disinfection should be provided. Published by Elsevier Inc. on behalf of the Association for Professionals in Infection Control and Epidemiology, Inc.

No studies to date have fully evaluated the fate and transport of microbes relative to surface varieties common to healthcare settings, including both hard, non-porous and soft, porous surfaces. Understanding the potential for mixed surface cross-contamination and the relationship between transport mechanisms and patient risks is important for effective infection control. This research engaged infection prevention, environmental service, and other healthcare personnel in the identification of needs and best practices in surface decontamination. Additionally, a microbial tracer was used to track pathogen fate and transport potentials during routine operations. Online surveys were administered to 129 healthcare workers. Bacteriophage tracers were seeded on a volunteer's hands or a single surface in 6 healthcare sites (physician offices and long-term care facilities). After 4 hours, surfaces (n=167) were swabbed for microbial tracers. Survey data indicated that the majority of healthcare professionals are concerned about soft surface contamination but do not clean them as frequently as hard surfaces. More than a third of respondents are unaware of soft surface decontamination solutions. Up to 70% of long-term care facility and 42% of physician office soft surfaces tested positive for the tracer. Data show rapid transfer of microbes within the healthcare setting and indicate a need for improved and comprehensive infection control procedures. Critical is the consideration of all surface textiles and materials, as an assembly, to identify areas with high levels of bioburden and the highest risk of cross-contamination. Research gaps include the need for determining transmission paths of microbes and an understanding of human interaction with surfaces. This additional research will provide valuable insight into ideal surface characteristics, optimum timing for hand hygiene, and support the development of evidence based effective cleaning and disinfection protocols and processes to interrupt the spread of pathogens.

AimsIn the present study, we conducted a quantitative microbial risk assessment forecasting the exposure to Campylobacter jejuni contaminated surfaces during preparation of chicken fillets and how using a disinfectant-wipe intervention to clean a contaminated work area decreases the risk of infection following the preparation of raw chicken fillet in a domestic kitchen.Methods and ResultsUsing a Monte Carlo simulation of the risk of transferring Camp.jejuni strain A3249, from various surfaces to hands and subsequently transferring it to the mouth was forecasted. The use of a disinfectant-wipe intervention to disinfect contaminated surface area was also assessed. Several assumptions were used as input parameters in the classical Beta-Poisson model to determine the risk of infection. The disinfectant-wipe intervention reduced the risk of Camp.jejuni infection by 2-3 orders on all fomites.ConclusionsThe use of disinfectant wipes after the preparation of raw chicken meat reduces the risk of Camp.jejuni infections.Significance and Impact of the StudyThis risk assessment shows that the use of disinfectant wipes to decontaminate surface areas after chicken preparation reduces the annual risk of Camp.jejuni infections up to 992%, reducing the risk from 2:10 to 2:1000.