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Background Candida auris is a globally emerging multidrug-resistant fungal pathogen. It causes healthcare-associated infections (HAIs) and can be transmitted through contaminated surfaces and equipment. Pre-wetted disinfectant towelettes are increasingly used for infection control. Our objective was to test the efficacies of EPA registered disinfectant towelette products, with or without fungicidal claims, against C. auris, on hard, non-porous surfaces below, at, and beyond label contact times. or longer contact times. We hypothesized that towelette disinfection efficacy against C. auris would be significantly influenced by chemistry and contact time. Methods We tested one hydrogen peroxide (HP), three quaternary ammonium (QAC), and one quaternary ammonium plus alcohol (QAC-alcohol)-based disinfectant towelette products, with or without EPA registered fungicidal claims, against C. auris Satoh et Makimura (ATCC MYA-5001). All products were tested at 30 s, one-, two-, three- and 10-min contact time to compare their overall efficacies on a defined surface area following modifications to standard EPA protocol MB-33-00. Results HP-based disinfectant towelettes were more efficacious against C. auris than the QAC-alcohol-based disinfectant towelettes irrespective of tested contact times. Thirty s contact time was significantly less effective in reducing C. auris from the Formica surface compared to one-, two-, three-, and 10-min contact times. However, there were no statistically significant differences in the level of disinfection among one-min and longer contact times regardless of product chemistry. None of the products achieved a standard six-log10 reduction at any tested contact times. Conclusion Overall, the HP-based disinfectant towelette was significantly more fungicidal than the QAC-alcohol-based disinfectant towelette. For all product types, 30 s contact time did not achieve the same level of disinfection as one-min or longer contact times. Overall, disinfectant towelette efficacy is dependent upon product formulation and contact time.

Background The use of disinfectants, such as disinfectant towelettes, play an important role pathogen transmission that can lead to healthcare-associated infections (HAIs). However, the efficacy of disinfectant towelette products when tested under realistic use conditions is understudied. A test model was designed to replicate realistic wiping conditions. The objective of this study was to determine the impact of varied contact time on disinfectant towelette efficacy under these conditions. Methods Five product types were tested against Staphylococcus aureus (ATCC 6538) and Pseudomonas aeruginosa (ATCC 15442) at five contact times (30 s, one min, two min, three min, and 10 min) on hard, non-porous laminate templates to determine the impact of contact time on disinfectant towelette efficacy when tested under realistic use. Results Product type had a significant impact on the efficacy of disinfectant towelettes when tested under conditions reflective of realistic use. The effect of contact time was limited and no differences in efficacy were seen at a contact time of one min compared with the other contact times tested. Only one disinfectant towelette product achieved a 5-log reduction under the tested conditions. Conclusion Efficacy of disinfectant towelettes was primarily impacted by product type when applied in a model designed to replicate realistic use in which only a limited effect of contact time was observed. There is a need for further investigation into which factors have the greatest impact on disinfectant towelette efficacy when applied in clinical settings.

Optimization of automated floor disinfection practices using different application methods and product types is important to ensure that pathogens such as Staphylococcus aureus do not transfer from contaminated floors to other high contact areas resulting in healthcare-associated infections (HAIs). We hypothesized that there would be significant differences among the disinfectants and a cleaner under different application methods. Also, performance of application methods would be dependent upon type of product used.We tested and compared efficacies of 5 EPA registered disinfectants and one cleaner using an automated Taski 455B floor cleaner against S aureus ATCC 6538 on 2 meters of contaminated vinyl flooring using 3 application methods.Hydrogen peroxide and quaternary ammonium compounds were more efficacious against S aureus than the neutral cleaner. There were no significant differences among the sampling areas tested and application methods regardless of product type. Mean logAll disinfectants had more bactericidal efficacy than the cleaner for all sampling zones on the tested floor. Overall, performance of the floor machine is dependent upon the type of product used.

Background Pre-wetted disinfectant wipes are increasingly being used in healthcare facilities to help address the risk of healthcare associated infections (HAIs). However, HAIs are still a major problem in the US with Clostridioides difficile being the most common cause, leading to approximately 12,800 deaths annually in the US. An underexplored risk when using disinfectant wipes is that they may cross-contaminate uncontaminated surfaces during the wiping process. The objective of this study was to determine the cross-contamination risk that pre-wetted disinfectant towelettes may pose when challenged with C. difficile spores. We hypothesized that although the tested disinfectant wipes had no sporicidal claims, they will reduce spore loads. We also hypothesized that hydrogen peroxide disinfectant towelettes would present a lower cross-contamination risk than quaternary ammonium products. Methods We evaluated the risk of cross-contamination when disinfectant wipes are challenged with C. difficile ATCC 43598 spores on Formica surfaces. A disinfectant wipe was used to wipe a Formica sheet inoculated with C. difficile. After the wiping process, we determined log10 CFU on previously uncontaminated pre-determined distances from the inoculation point and on the used wipes. Results We found that the disinfectant wipes transferred C. difficile spores from inoculated surfaces to previously uncontaminated surfaces. We also found that wipes physically removed C. difficile spores and that hydrogen peroxide disinfectants were more sporicidal than the quaternary ammonium disinfectants. Conclusion Regardless of the product type, all disinfectant wipes had some sporicidal effect but transferred C. difficile spores from contaminated to otherwise previously uncontaminated surfaces. Disinfectant wipes retain C. difficile spores during and after the wiping process.

Background Disinfectant products are used frequently on environmental surfaces (e.g. medical equipment, countertops, patient beds) and patient care equipment within healthcare facilities. The purpose of this study was to assess the risk of cross-contamination of Staphylococcus aureus and Pseudomonas aeruginosa during and after disinfection of predetermined surface areas with ready-to-use (RTU) pre-wetted disinfectant towelettes. Methods This study tested six disinfectant towelette products against S. aureus ATCC CRM-6538 and P. aeruginosa strain ATCC-15442 on Formica surfaces. Each disinfectant was evaluated on a hard nonporous surface and efficacy was measured every 0.5 m2 using a modified version of EPA MLB SOP-MB-33 to study the risk of cross-contamination. Results We found that all of the wipes used in this study transferred S. aureus and P. aeruginosa from an inoculated surface to previously uncontaminated surfaces. Disinfectant towelettes with certain chemistries also retained a high level of viable bacteria after disinfection of the surface area. The cross-contamination risk also varied by product chemistry and bacterial strain. Conclusion Disinfectant wipes can cross-contaminate hard nonporous surfaces and retain viable bacterial cells post-disinfection, especially over larger surface areas. This highlights a need to further investigate the risk disinfectant wipes pose during and post-disinfection and guidance on maximum surface areas treated with a single towelette.

Globally, healthcare-associated infections (HAI) are the most frequent adverse outcome in healthcare delivery. Although bacterial biofilms contribute significantly to the incidence of HAI, few studies have investigated the efficacy of common disinfectants against dry-surface biofilms (DSB). The objective of this study was to evaluate the bactericidal efficacy of seven Environmental Protection Agency (EPA)-registered liquid disinfectants against DSB of

Background Disinfectant towelettes are commonly used for surface disinfection to prevent health care–associated infections; however, there is limited consensus as to whether a surface needs to remain wet for the full label contact time after the disinfectant towelette has been used in order for complete efficacy to be achieved. The purpose of this study was to quantify the effect of contact time, including times before and after a product dries, on bactericidal efficacy of 6 towelette products registered by the Environmental Protection Agency . Methods Six disinfectant towelette products were tested at varying contact times, including defined label contact times. Quantitative Environmental Protection Agency MB-33-00 was used to measure disinfectant efficacy against Staphylococcus aureus on Formica. Complete dry time for each disinfectant was measured gravimetrically. Results There were significant differences in dry times among the towelette products; contact time did not have a significant effect on bactericidal efficacy. There was no longitudinal effect when a disinfectant's contact time was greater than defined label contact time, irrespective of whether the product was wet or dry on the surface. Discussion Overall, bactericidal efficacy varied by towelette product tested and surface area wiped. Wiping larger surface areas may lead to decreased bactericidal efficacy but is product dependent. Conclusions There was no additional bactericidal effect after a product dried, indicating that extended contact times beyond when the product dries will not enhance disinfection.

Background: Globally, healthcare associated infections (HAI) are the most frequent adverse outcome in healthcare delivery. Although bacterial biofilms contribute significantly to the incidence of HAI, few studies have investigated the efficacy of common disinfectants against dry surface biofilms (DSB). The objective of this study was to evaluate the bactericidal efficacy of seven disinfectants against DSB of Staphylococcus aureus and Pseudomonas aeruginosa. We hypothesized that overall, hydrogen peroxides, sodium dichloro-s-triazinetrione and quaternary ammonium compounds plus alcohol disinfectants will be more bactericidal against DSB than quaternary ammonium. We also hypothesized that regardless of differences in product chemistries, higher bactericidal efficacies against DSB will be exhibited after 24 h of dehydration compared to 72 h.Methods: Wet surface biofilms of S. aureus and P. aeruginosa were grown following EPA-MLB-SOP-MB-19 and dehydrated for 24 h and 72 h to establish DSB. Seven EPA-registered disinfectants were tested against dehydrated DSB following EPA-MLB-SOP-MB-20. Results: Overall, quaternary ammonium plus alcohol, sodium dichloro-s-triazinetrione, and hydrogen peroxide products were more efficacious against DSB than quaternary ammoniums for both tested strains. While there was no significant difference in biofilm killing efficacies between 24 h and 72 h S. aureus biofilms, significantly higher log10 reductions were observed when products were challenged with 24 h P. aeruginosa DSB compared to 72 h P. aeruginosa DSB. Conclusion: Strain type, active ingredient class, and dry time significantly impact disinfectant efficacy against DSB of S. aureus or P. aeruginosa.

Background Bacterial biofilms persistent on dry environmental surfaces in healthcare facilities play an important role in the occurrence of healthcare associated infections (HAI). Compared to wet surface biofilms and planktonic bacteria, dry surface biofilms (DSB) are more tolerant to disinfection. However, there is no official method for developing DSB for in vitro disinfectant efficacy testing. The objectives of this study were to (i) develop an in vitro model of DSB of S. aureus and P. aeruginosa for disinfectant efficacy testing and (ii) investigate the effect of drying times and temperatures on DSB development. We hypothesized that a minimum six log10 density of DSB could be achieved on glass coupons by desiccating wet surface biofilms near room temperatures. We also hypothesized that a DSB produced by the model in this study will be encased in extracellular polymeric substances (EPS). Methods S. aureus ATCC-6538 and P. aeruginosa ATCC-15442 wet surface biofilms were grown on glass coupons following EPA MLB SOP MB-19. A DSB model was developed by drying coupons in an incubator and viable bacteria were recovered following a modified version of EPA MLB SOP MB-20. Scanning electron microscopy was used to confirm the EPS presence on DSB. Results Overall, a minimum of six mean log10 densities of DSB for disinfectant efficacy were recovered per coupon after drying at different temperatures and drying times. Regardless of strain, temperature and dry time, 86% of coupons with DSB were confirmed to have EPS. Conclusion A rapid model for developing DSB with characteristic EPS was developed for disinfectant efficacy testing against DSB.

Background: Pre-wetted disinfectant wipes are increasingly being used in healthcare facilities to help address the risk of healthcare associated infections (HAI). However, HAIs are still a major problem in the US with Clostridioides difficile being the most common cause, leading to approximately 12,800 deaths annually in the US. An underexplored risk when using disinfectant wipes is that they may cross-contaminate uncontaminated surfaces during the wiping process. The objective of this study was to determine the cross-contamination risk that pre-wetted disinfectant towelettes may pose when challenged with C. difficile spores. We hypothesized that although the tested disinfectant wipes had no sporicidal claims, they will reduce spore loads. We also hypothesized that hydrogen peroxide disinfectant towelettes would present a lower cross-contamination risk than quaternary ammonium products. Methods: We evaluated the risk of cross-contamination when disinfectant wipes are challenged with C. difficile ATCC 43598 spores on Formica surfaces. A disinfectant wipe was used to wipe a Formica sheet inoculated with C. difficile. After the wiping process, we determined log10 CFU on previously uncontaminated pre-determined distances from the inoculation point and on the used wipes. Results: We found that the disinfectant wipes transferred C. difficile spores from inoculated surfaces to previously uncontaminated surfaces. We also found that wipes physically removed C. difficile spores and that hydrogen peroxide disinfectants were more sporicidal than the quaternary ammonium disinfectants. Conclusion: Regardless of the product type, all disinfectant wipes had some sporicidal effect but transferred C. difficile spores from contaminated to otherwise previously uncontaminated surfaces. Disinfectant wipes retain C. difficile spores during and after the wiping process.

Background Disinfectant products are often used on environmental surfaces (e.g. countertops, patient beds) and patient care equipment in healthcare facilities to help prevent the transmission of healthcare-associated infections. Ready-to-use (RTU) disinfectants in the form of pre-wetted towelettes are increasingly popular among healthcare facilities. Currently, the EPA does not require disinfectant manufacturers to include a recommended maximum surface area per towelette on their product labels. The objective of this study was to investigate the efficacy of disinfectant towelette products on a hard non-porous surface across different coverage areas using a quantitative EPA method. We hypothesized that there would be significant differences in the efficacy of disinfectant towelette products, and that the greater surface area(s) wiped would result in reduced bactericidal efficacy. Methods This study tested ten disinfectant towelette products against Staphylococcus aureus strain ATCC CRM-6538 and Pseudomonas aeruginosa strain ATCC 15442 on Formica surfaces. Defined surface areas were wiped and the towelette weighed before and after wiping to determine the amount of liquid released. Bactericidal efficacy testing was also performed after wiping following standard EPA protocols. Results We found that disinfectant product, area of surface wiped, and strain impacted the bactericidal efficacy achieved. Disinfectant product type and area of surface wiped significantly impacted the percent of liquid released per ft2from the towelette. Conclusion Overall, bactericidal efficacy varied by towelette product, surface area wiped, and strain. This study also found that wiping larger surface areas may lead to decreased bactericidal efficacy. Further research is needed to test its implication.

Effective disinfection in healthcare facilities prevents healthcare-associated infections. This study evaluated the ability of Environmental Protection Agency-approved disinfectants (quaternary ammonium compound, QAC; sodium hypochlorite, and hydrogen peroxide) applied with 3 wiping substrates (microfiber, nonwoven, and cotton) to remove Staphylococcus aureus from Formica surfaces. All treatments reduced S aureus on Formica squares with the exception of QAC applied with cotton and QAC, nondisinfectant, and control applied with a nonwoven cloth. Sodium hypochlorite or hydrogen peroxide applied with cotton or microfiber, respectively, may be the best choice for disinfection of Formica surfaces in healthcare settings.

The use of prewetted disinfectant towelettes in health care settings proves challenging because they may dry quickly, reducing disinfection. This study examined the drying time of various commercial disinfectant towelettes and the efficacy of these towelettes over time to eliminate Staphylococcus aureus from glass surfaces. This study confirms that these disinfectants dry quickly. Further disinfection after drying time on glass is minimal, but dependent on the type of disinfectant.

Background The objective of this study was to evaluate the extent and potential mechanisms of early onset surface damage from simulated wiping typical of six-months of routine disinfection and to assess the subsequent microbial risk of surfaces damaged by disinfectants. Methods Eight common material surfaces were exposed to three disinfectants and a neutral cleaner (neutral cleaner, quaternary ammonium, hydrogen peroxide, sodium hypochlorite) in accelerated aging tests to simulate a long-term disinfection routine. Materials were also immersed in dilute and concentrated chemical solutions to induce surface damage. Surfaces were chemically and physically characterized to determine extent of surface damage. Bactericidal efficacy testing was performed on the Quat-based disinfectant using a modified version of EPA standard operating procedure MB-25-02. Results The wiping protocol increased surface roughness for some material surfaces due to mechanical abrasion of the wiping cloth. The increased roughness did not correlate with changes in bactericidal efficacy. Chemical damage was observed for some surface-disinfectant combinations. The greatest observed effects from disinfectant exposure was in changes in wettability or water contact angle. Conclusions Early onset surface damage was observed in chemical and physical characterization methods. These high-throughput material measurement methods were effective at assessing nanoscale disinfectant-surface compatibility which may go undetected though routine macroscale testing.

Healthcare-associated infections are a significant concern in acute care facilities across the US. Studies have shown the importance of a hygienic patient environment in reducing the risk of such infections. This has caused an increased interest in ultraviolet (UV-C) light disinfectant technology as an adjunct technology to provide additional pathogen reduction to environmental surfaces and patient care equipment (i.e., surfaces). It is also well known that UV-C light can cause premature degradation of materials, particularly certain plastic materials. However, there is little information in the literature regarding characterizing this degradation of plastics and other materials used for surfaces in healthcare. This study aims to evaluate multiple characterization techniques and propose a systematic approach to further understand early onset degradation of plastics due to UV-C exposure. Susceptibility and modes of degradation of multiple plastic materials were compared using the techniques evaluated. Ten grades of plastic materials were exposed to UV-C light in a manner consistent with standards given in the healthcare and furniture industry to achieve disinfection. These materials were characterized for visual appearance, chemical composition, surface roughness and hardness using light microscopy, spectrophotometry, contact angle analysis, infrared spectroscopy, profilometry and nanoindentation. All characterization methods were able to identify one or more specific degradation features from UV-C exposure covering different aspects of physicochemical properties of the surfaces. However, these methods showed different sensitivity and applicability to identify the onset of surface damage. Different types of surface materials showed different susceptibility and modes to degradation upon UV-C light exposure. UV-C disinfection can cause detectable damage to various surfaces in healthcare. A characterization approach consisting of physical and chemical characterizations is proposed in quantifying surface degradation of a material from UV-C exposure to address the complexity in modes of degradation and the varied sensitivity to UV-C from different materials. Methods with high sensitivity can be used to evaluate onset of damage or early stage damage.

Background Transmission of healthcare-associated infections caused by antibiotic- and multi-drug resistant (MDR) pathogens (e.g. Methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa) are a major concern in patient care facilities. Disinfectant usage is critical to control and prevent pathogen transmission, yet the relationships among strain, disinfectant type, contact time, and concentration are not well-characterized. We hypothesized that there would be significant differences in disinfectant efficacy among clinically relevant strains under off-label disinfectant conditions, but there would be less no differences among at registered label use concentrations and contact times. The purpose of this study was to quantify the effect of disinfectant concentration and contact time on the bactericidal efficacy of clinically relevant strains of S. aureus and P. aeruginosa. Methods Accelerated hydrogen peroxide (AHP), quaternary ammonium compounds (Quat), and sodium hypochlorite were tested at label and reduced contact times and concentrations against four MDR P. aeruginosa strains and four MRSA strains. Quantitative EPA method MB-25-02 was used to measure disinfectant efficacy reported as log10 reduction. Results Both off-label disinfectant concentrations and contact times significantly affected efficacy of all disinfectants tested. Bactericidal efficacy varied among MRSA and P. aeruginosa strains. Conclusions The quantitative disinfectant efficacy method used highlights the inter-strain variability that exists within a bacterial species. It also underscores the need for a disinfectant validation method that takes these variances into account.

Healthcare-Associated Infections (HAIs) are a significant cause of morbidity and mortality and occur in many healthcare facilities including hospitals, surgery centers and long-term care facilities. It is well known that some pathogens can persist on healthcare surfaces for weeks to months and spread readily to new surfaces. It is current practice to disinfect or clean surfaces routinely in order to reduce the risk of HAIs. However, routine cleaning can damage the surface chemically or mechanically, which may actually increase the surface contamination. Fundamental knowledge is therefore needed to understand the influence of cleaning and disinfection on healthcare surfaces in order to mitigate pathogen persistence. In this study, materials and objects found in healthcare facilities were selected and exposed to disinfection procedures including wiping and soaking with readily available chemical disinfectants. A variety of chemical disinfectants were selected which contain hydrogen peroxide, quaternary ammonia, and chlorine, respectively. Optical microscopy, contact angle measurement, atomic force microscopy (AFM), Fourier Transform Infrared (FTIR) spectroscopy and nanoindentation are used to analyze surface characteristics before and after disinfection in order to study the effect of disinfection on material properties. Disinfection procedures are found to cause changes to surface properties of materials and objects which can be detected and observed or quantified by the approaches used in this study. The methods should become regular practice in the studies of healthcare surfaces and their role in HAIs. Each method in this study may not be reliably applied to every object or disinfection scenario. Sample geometry and features may influence response during measurement and affect results. The combination of the approaches is able to sufficiently characterize chemical, mechanical, and topological changes to the surface.

This study investigated the influence of contact time and concentration on bactericidal efficacy of 3 types of disinfectants (accelerated hydrogen peroxide [AHP], quaternary ammonium compounds [Quats], and sodium hypochlorite) on stainless steel surfaces using Environmental Protection Agency procedure MB-25-02. We found that bactericidal efficacy was not reduced at contact times or concentrations immediate lower than label use values, but all 3 disinfectants were significantly less bactericidal at significantly lower than label use contact times and concentrations. Overall, the bactericidal efficacy of the sodium hypochlorite disinfectant was most tolerant to the decreases of contact times and concentrations, followed closely by AHP disinfectant, and Quat disinfectant was most affected by contact time and concentration.

METHODS: Eight environmental specimens and 23 clinical specimens were grown on C.diff chromogenic agar at 30 2 C after 48 4 hours of incubation under anaerobic conditions. Suspicious blackcolored colonies from chromogenic agar were further subjected to C.diff latex agglutination and MALDI-TOF MS for identification. Data from the 3 different methodologies: black colonies, latex agglutination and MALDI-TOF were compared for concurrence of Results. RESULTS: There was 100% agreement among the three different identification methodologies. MADLI-TOF was able to identify the C.diff specimens with >90% accuracy on all of the isolates. The identification process for C.diff chromogenic agar and latex agglutination was relatively simple. The cost of chromogenic agar with the anaerobic system was w$5, latex agglutination cost/ per test was w$6 and MALDI-TOF was the least expensive at w$1 per sample, but, the initial equipment cost was quite steep (>$50,000). CONCLUSIONS: Our study indicates that there is a good correlation among the three methodologies when it comes to identifying environmental or clinical specimens. C.diff spores can be grown and reliably identified using color on the chromogenic media. But, for definite confirmation, latex agglutination or MALDI-TOF are great alternatives when initial costs can be absorbed.

ISSUE: Multiple studies have shown that high-touch surfaces, such as bed rails, over bed tables, and supply carts, play a role in the transmission of pathogens to susceptible patients. It was demonstrated that current cleaning practices result in high-touch surfaces being adequately disinfected less than half the time. While there are novalidated standardized practices for cleaning anddisinfection (CD) of patient rooms, there are recommended processes. We conducted an audit of patient room cleaning in acute care facilities to identify current gaps and developed a model for CD of a patient room.