The crucial role of wiping in decontamination of high-touch environmental surfaces: review of current status and directions for the future

Mechanisms of action of microbicides commonly used in infection prevention and control

SUMMARYUnderstanding how commonly used chemical microbicides affect pathogenic microorganisms is important for formulation of microbicides. This review focuses on the mechanism(s) of action of chemical microbicides commonly used in infection prevention and control. Contrary to the typical site-specific mode of action of antibiotics, microbicides often act via multiple targets, causing rapid and irreversible damage to microbes. In the case of viruses, the envelope or protein capsid is usually the primary structural target, resulting in loss of envelope integrity or denaturation of proteins in the capsid, causing loss of the receptor-binding domain for host cell receptors, and/or breakdown of other viral proteins or nucleic acids. However, for certain virucidal microbicides, the nucleic acid may be a significant site of action. The region of primary damage to the protein or nucleic acid is site-specific and may vary with the virus type. Due to their greater complexity and metabolism, bacteria and fungi offer more targets. The rapid and irreversible damage to microbes may result from solubilization of lipid components and denaturation of enzymes involved in the transport of nutrients. Formulation of microbicidal actives that attack multiple sites on microbes, or control of the pH, addition of preservatives or potentiators, and so on, can increase the spectrum of action against pathogens and reduce both the concentrations and times needed to achieve microbicidal activity against the target pathogens.

Impact of artificial accelerated ageing of PVC surfaces and surface degradation on disinfectant efficacy

BACKGROUND

Standardized efficacy surface tests for disinfectants are performed on pristine surfaces. There is a growing interest in understanding the impact of surface ageing on disinfectant activity, owing for example to the increased usage of ultraviolet (UV) radiation and oxidative chemistries for surface decontamination. This acknowledges that general surface 'wear and tear' following UV radiation and oxidative biocide exposure may impact biocidal product efficacy.

METHODS

PVC surfaces were aged through thermal and UV-A radiation (340 nm wavelength) following the use of standard ageing surface protocols to simulate natural surface degradation. Surface roughness, contact angle and scanning electron microscopy were performed to evaluate physical changes in PVC surfaces before and after artificial ageing. The efficacy of five pre-impregnated disinfectant wipes were evaluated using the ASTM E2967-15 on stainless-steel (control) and PVC surfaces (aged and non-aged).

RESULTS

The type of formulation and the organism tested remained the most significant factors impacting disinfectant efficacy, compared with surface type. Both thermal ageing and UV-A exposure of PVC surfaces clearly showed signs of surface degradation, notably an increase in surface roughness. Physical changes were observed in the roughness of PVC after artificial ageing. A difference in disinfectant efficacy dependent on aged PVC surfaces was observed for some, but not all formulations.

CONCLUSION

We showed that surface type and surface ageing can affect biocidal product efficacy, although in a non-predictable manner. More research is needed in this field to ascertain whether surface types and aged surfaces should be used in standardized efficacy testing.

Chemical resistance testing of plastics: material compatibility of detergent and disinfectant products

BACKGROUND

Surface cleaning and disinfection is a key part of breaking the chain of transmission and reducing the risk of healthcare associated infections. However, if cleaning and disinfectant formulations are incompatible with surface materials, frequent application can cause premature failure of plastics due to environmental stress cracking (ESC). Material compatibility should be considered when selecting cleaning and disinfecting products.

AIM

This study evaluated the tendency of 2-in-1 wet wipes to cause ESC in commonly found healthcare plastics.

METHODS

Eight ready-to-use 2-in-1 wet wipes were evaluated for their ability to cause ESC in 13 plastic surfaces in accordance with BS EN ISO-22088-3. Polymers were exposed to fluid extracted from wipes at a fixed strain of 0.5% for seven days and assessed for cracking, crazing, and tensile strength in accordance with ISO 527-2:2012.

FINDINGS

All 2-in-1 wet wipes tested contained ESC agents, although the severity of ESC varied. Products with higher pH (>8.0) were responsible for 74% of failures, with 22 of the 39 tested plastics visibly cracking. Although the primary active in all tested wipe formulations were quaternary ammonium compounds, formulations that included small/medium amines or alcohol demonstrated a greater propensity for plastic cracking.

CONCLUSION

Each disinfectant formulation exhibits a unique spectrum of microbial efficacy and unique potential to cause surface damage. This may result in device failures and recalls that could compromise patient and staff safety. BS EN ISO-22088-3 can support material compatibility assessments of disinfectant and detergent products before they come to market.

Contamination of equipment and surfaces in the operating room anesthesia workspace: a cross-sectional study

BACKGROUND

Contamination of the breathing circuit and medication preparation surface of an anesthesia machine can increase the risk of cross-infection.

OBJECTIVE

To evaluate the contamination of the anesthetic medication preparation surface, respiratory circuits, and devices used in general anesthesia with assisted mechanical ventilation.

DESIGN AND SETTING

Cross-sectional, quantitative study conducted at the surgical center of a philanthropic hospital, of medium complexity located in the municipality of Três Lagoas, in the eastern region of the State of Mato Grosso do Sul.

METHODS

Eighty-two microbiological samples were collected from the breathing circuits. After repeating the samples in different culture media, 328 analyses were performed.

RESULTS

A higher occurrence of E. coli, Enterobacter spp., Pseudomonas spp., Staphylococcus aureus, and Streptococcus pneumoniae (P < 0.001) were observed. Variations were observed depending on the culture medium and sample collection site.

CONCLUSION

The study findings underscore the inadequate disinfection of the inspiratory and expiratory branches, highlighting the importance of stringent cleaning and disinfection of high-touch surfaces.

Can the adenosine triphosphate (ATP) bioluminescence assay be used as an indicator for hospital cleaning? - A pilot study

Background

In hospital cleaning, there is currently no standard for uniform monitoring of surface cleaning, either in Germany or internationally. One possibility for monitoring is the use of so-called objective methods for checking cleaning performance (e.g. fluorescence or adenosine triphosphate (ATP) method).

Aim

The aim of the study was to monitor and evaluate the implementation of the adenosine triphosphate (ATP) bioluminescence assay as a cleaning indicator in everyday hospital cleaning, in order to verify its utility and effectiveness.

Methods

In three phases, five frequently touched surfaces were examined with the ATP bioluminescence assay at different time points. 846 measurements were performed on the dermatology ward of a university hospital (phase 1), 1,350 measurements were performed on five different wards of the university hospital (phase 2), and 1,044 measurements were performed on five wards of another large hospital (phase 3). For this purpose, one structurally old and one structurally new ward as well as an intensive care unit (ICU), an outpatient clinic and a radiology department were selected for phases 2 and 3.

Results

With the ATP bioluminescence method, we were able to demonstrate a reduction in values after cleaning: before cleaning mean of ATP, 907 relative light units (RLU) (95% confidence interval [CI] 777; 1,038); after cleaning mean=286 RLU (CI=233; 495) (phase 1) and by intervention (five hours after daily cleaning mean=360 RLU (CI=303; 428); five hours after daily cleaning and two additional cleanings mean=128 RLU (CI=107; 152) (phase 3). The ATP values increased five hours after cleaning in phases 1 and 2, and eight hours after cleaning in phase 3. The structurally old wards had the highest ATP content, the ICU and the radiology department, among others, the lowest. In all phases, door handles showed both a reduction after cleaning or intervention and a subsequent increase in ATP values. Chair armrests, examination tables and door handles had high ATP values overall.

Conclusion

The study shows ward differences both for cleaning effects and for the soiling characteristics of surfaces during the course of the day. In addition, it demonstrates the benefit of intermediate cleaning twice a day. It is noteworthy that structurally old stations and older inventory were more heavily soiled and, in some cases, more difficult to clean. The results show that the ATP bioluminescence method is suitable for detecting cleaning effects and can be used in everyday clinical practice for simple cleaning monitoring. Furthermore, it enables the detection of risk surfaces and easy-to-clean surfaces with significant re-soiling.

Piercing of the Human Parainfluenza Virus by Nanostructured Surfaces

This paper presents a comprehensive experimental and theoretical investigation into the antiviral properties of nanostructured surfaces and explains the underlying virucidal mechanism. We used reactive ion etching to fabricate silicon (Si) surfaces featuring an array of sharp nanospikes with an approximate tip diameter of 2 nm and a height of 290 nm. The nanospike surfaces exhibited a 1.5 log reduction in infectivity of human parainfluenza virus type 3 (hPIV-3) after 6 h, a substantially enhanced efficiency, compared to that of smooth Si. Theoretical modeling of the virus-nanospike interactions determined the virucidal action of the nanostructured substrata to be associated with the ability of the sharp nanofeatures to effectively penetrate the viral envelope, resulting in the loss of viral infectivity. Our research highlights the significance of the potential application of nanostructured surfaces in combating the spread of viruses and bacteria. Notably, our study provides valuable insights into the design and optimization of antiviral surfaces with a particular emphasis on the crucial role played by sharp nanofeatures in maximizing their effectiveness.

Multimodal environmental cleaning strategies to prevent healthcare-associated infections

Infection transmission in healthcare is multifaceted and by in large involves the complex interplay between a pathogen, a host and their environment. To prevent transmission, infection prevention strategies must also consider these complexities and incorporate targeted interventions aimed at all possible transmission pathways. One strategy to prevent and control infection is environmental cleaning. There are many aspects to an environmental cleaning strategy. We believe the key to successfully reducing the risk of healthcare-associated infections through the environment, is to design and implement a multimodal intervention. This paper aims to provide an overview of important considerations for designing a meaningful and sustainable environmental program for healthcare facilities.

Biocidal effects of a wipe-down procedure using common veterinary cleansers on microbial burden within working canine exterior coats

Introduction

Recent work demonstrating reduction of aerosolized contamination via a wipe-down procedure using common veterinary antiseptics offers promise regarding health concerns associated with cross-contamination from working canines to humans. While mechanical reduction can be achieved via a wipe-down procedure, the biocidal impact on flora within the exterior coat is unknown.

Methodology

This study assessed the biocidal impact of antiseptics on the exterior bacterial community of the canine. Lint-free towels were saturated with 2% chlorhexidine gluconate scrub, or 7.5% povidone-iodine scrub diluted at a 1:4 ratio. Treatments were rotated across the dorsal aspect of kennel housed Foxhounds (n = 30). Sterile swabs were collected in triplicate prior to, and following wipe down, stored in Amies solution at 4°C, plated onto nutrient agar and reduction in colony forming units (CFU) was measured across both treatments. Statistical analysis utilizing PROC GLM examined effects of treatment (p ≤ 0.05). Molecular analysis of the 16S rRNA gene was completed for 3 hounds.

Results

Reduction in CFU was measured (p < 0.001) for both antiseptics. Qualitative molecular data indicated that both antiseptics had a biocidal effect on the dominant microbial community on the exterior coat with gram-positive, spore-forming taxa predominating post-treatment.

Conclusion

Effective wipe-down strategies using common veterinary cleansers should be further investigated and incorporated to safeguard working canine health and prevent cross-contamination of human personnel.

Contact time has limited impact on the efficacy of disinfectant towelettes when tested under conditions reflective of realistic use

BACKGROUND

Disinfectant towelettes are increasingly being used as a means to prevent transmission of clinically important pathogens which could 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 15,442) 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 mean 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.

The impact of bedside wipes in multi-patient rooms: a prospective, crossover trial evaluating infections and survival

BACKGROUND

Multidrug-resistant organisms (MDROs) are prevalent on high-touch surfaces in multi-patient rooms.

AIM

To quantify the impact of hanging single-use cleaning/disinfecting wipes next to each bed. Pre-specified outcomes were: (1) hospital-acquired infections (HAIs), (2) cleaning frequency, (3) MDRO room contamination, (4) new MDRO acquisitions, and (5) mortality.

METHODS

Clustered randomized crossover trial at Shamir Medical Center, Israel (October 2016 to January 2018). Clusters were randomly assigned to use for cleaning either single-use quaternary ammonium wipes (Clinell) or standard practices (reusable cloths and buckets with bleach). Six-month intervention periods were implemented in alternating sequence, separated by a washout period. Five high-touch surfaces were monitored by fluorescent markers. Study outcomes were compared between periods using generalized estimating equations, Poisson regression, and Cox proportional hazards models.

FINDINGS

Overall, 7725 patients were included (47,670 person-days), 3793 patients in rooms with intervention cleaning and 3932 patients in rooms with standard practices. During the intervention, there was no significant difference in HAI rates (incidence rate ratio: 1.6; 95% confidence interval (CI): 0.7-3.5; P = 0.3). However, in intervention rooms, the frequency of environmental cleaning was higher (odds ratio: 3.73; 95% CI: 2.0-7.1; P < 0.0001), MDRO environmental contamination rate was insignificantly lower (odds ratio: 0.7; 95% CI: 0.5-1.0; P = 0.06), new MDRO acquisition rate was lower (hazard ratio: 0.4; 95% CI: 0.2-1.0; P = 0.04), and in-hospital mortality rate was lower (incidence rate ratio: 0.8; 95% CI: 0.7-1.0; P = 0.03).

CONCLUSION

Hanging single-use cleaning/disinfecting wipes next to each bed did not affect the HAI rates but did improve the frequency of cleaning, reduce MDRO environmental contamination, and was associated with reduced incidence of new MDRO acquisitions and reduced mortality. This is a feasible, recommended practice to improve patient outcomes in multi-patient rooms.

Efficacy of chemical disinfectants against SARS-CoV-2 on high-touch surface materials

AIMS

This study aimed to provide operationally relevant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) surface disinfection efficacy information.

METHODS AND RESULTS

Three EPA-registered disinfectants (Vital Oxide, Peroxide, and Clorox Total 360) and one antimicrobial formulation (CDC bleach) were evaluated against SARS-CoV-2 on material coupons and were tested using Spray (no touch with contact time) and Spray & Wipe (wipe immediately post-application) methods immediately and 2 h post-contamination. Efficacy was evaluated for infectious virus, with a subset tested for viral RNA (vRNA) recovery. Efficacy varied by method, disinfectant, and material. CDC bleach solution showed low efficacy against SARS-CoV-2 (log reduction < 1.7), unless applied via Spray & Wipe. Additionally, mechanical wiping increased the efficacy of treatments against SARS-CoV-2. The recovery of vRNA post-disinfection suggested that vRNA may overestimate infectious virus remaining.

CONCLUSIONS

Efficacy depends on surface material, chemical, and disinfection procedure, and suggests that mechanical wiping alone has some efficacy at removing SARS-CoV-2 from surfaces. We observed that disinfectant treatment biased the recovery of vRNA over infectious virus.

SIGNIFICANCE AND IMPACT OF STUDY

These data are useful for developing effective, real-world disinfection procedures, and inform public health experts on the utility of PCR-based surveillance approaches.

Efficacy of hydrogen peroxide wipes for decontamination of AZD1222 adenovirus COVID-19 vaccine strain on pharmaceutical industry materials

This study aimed to evaluate the performance of accelerated hydrogen peroxide® wipes (HPW) for decontamination of the chimpanzee adenovirus AZD1222 vaccine strain used in the production of recombinant COVID‐19 vaccine in a pharmaceutical industry. Two matrices were tested on stainless‐steel (SS) and low‐density‐polyethylene (LDP) surfaces: formulated recombinant COVID‐19 vaccine (FCV) and active pharmaceutical ingredient (API). The samples were spiked, dried and the initial inoculum, possible residue effect (RE) and titre reduction after disinfection with HPW were determined. No RE was observed. The disinfection procedure with HPW resulted in complete decontamination the of AZD1222 adenovirus strain in FCV (≥7·46 and ≥7·49 log₁₀ infectious unit [IFU] ml⁻¹ for SS and LDP carriers respectively) and API (≥8·79 and ≥8·78 log₁₀ IFU ml⁻¹ for SS and LDP carriers respectively). In conclusion, virucidal activity of HPW was satisfactory against the AZD1222 adenovirus strain and can be a good option for disinfection processes of SS and LPD surfaces in pharmaceutical industry facilities during recombinant COVID‐19 vaccine production. This procedure is simple and can be also applied on safety unit cabins and sampling bags made of LDP as well.

A sustainable approach for the utilization of PPE biomedical waste in the construction sector

One of the major challenges the COVID-19 pandemic has posed is the disposal of huge volumes of biomedical waste. It is the need of the hour to find out methods to handle the waste generated and explore novel and sustainable ways for their disposal. Personal Protective Equipment (PPE) is the main medical waste generated during the pandemic and may continue to accumulate in the post-pandemic era. This paper portrays a study on generating construction material composites from PPE waste along with the sand fillers. The work has been carried out with two different sand, River sand and Manufactured sand, in three different filler ratios. The different properties such as tensile, compression, and flexural strength of the prepared composite are detailed and compared with the existing construction materials. Durability properties such as acid resistance and moisture absorption have been studied to validate the efficacy of the developed material in the construction sector. It is observed that the PPE waste composite displays superior performance in compression, tension and flexure while compared to the other construction materials like mud bricks and cement blocks. The water absorption and acid degradation are minimal, as a result, its strength is not affected after exposure to such adverse conditions. The thermal conductivity of the composite is found to be less compared to the conventional concrete which makes it an ideal choice in tropical areas as thermal insulation material. Moving forward, this study is expected to set a new sustainable approach to utilize biomedical plastics waste to substitute cement-based construction material and hence aid a negative carbon cycle.

A review of HTM 01-05 through an environmentally sustainable lens

Patients deserve to be treated in a safe and clean environment with consistent standards of care every time they receive treatment. It is essential that the risk of person-to-person transmission of infections be minimised, yet it is also essential that planetary harm (and therefore public harm) is minimised with respect to resource consumption, air pollution, environmental degradation etc.In 2013, the Department of Health introduced the Health Technical Memorandum (HTM) 01-05 providing dental practices with advice on patient safety when decontaminating reusable instruments in primary care. This paper provides a commentary on HTM 01-05 and similar decontamination guidance. We believe all decontamination documents needs to reflect the so-called 'triple bottom line' - the finance, social cost and impact on the planet.The authors provide an environmental commentary on a number of items mentioned in decontamination documents, including autoclaves (including the use of helix tests), disposable paper towels, undertaking hand hygiene, using a log book, plastic bag use, the use of personal protective equipment, remote decontamination units, single use instruments, single use wipes, disinfection chemicals (for example, sodium hypochlorite) thermal disinfection and wrapping of instruments.It is hoped, in the spirit of the ever-increasing numbers of papers published to highlight how healthcare (and dentistry) could become more sustainable, that these critiques will be taken in the spirit of providing a beginning of further discussion from an environmental perspective.

Preventing healthcare-associated infections by decontaminating the clinical environment

Healthcare-associated infections (HAIs) continue to cause patient harm and at increasing rates. Factors contributing to this increase include suboptimal hand hygiene, antimicrobial resistance, and inadequate decontamination of the patient environment and shared patient equipment. To reduce the risk of HAIs and enhance patient safety, it is important that nurses and other healthcare professionals adhere to infection prevention and control guidance, including decontamination procedures. It is also important to identify and address the barriers that can affect adherence to this guidance. This article discusses effective decontamination of the patient environment and non-critical shared patient equipment, the barriers to adhering to guidance and strategies for improving decontamination procedures.

Mechanical Wiping Increases the Efficacy of Liquid Disinfectants on SARS-CoV-2

High-touch environmental surfaces are acknowledged as potential sources of pathogen transmission, particularly in health care settings where infectious agents may be readily abundant. Methods of disinfecting these surfaces often include direct application of a chemical disinfectant or simply wiping the surface with a disinfectant pre-soaked wipe (DPW). In this study, we examine the ability of four disinfectants, ethanol (EtOH), sodium hypochlorite (NaOCl), chlorine dioxide (ClO2), and potassium monopersulfate (KMPS), to inactivate SARS-CoV-2 on a hard, non-porous surface, assessing the effects of concentration and contact time. The efficacy of DPWs to decontaminate carriers spiked with SARS-CoV-2, as well as the transferability of the virus from used DPWs to clean surfaces, is also assessed. Stainless steel carriers inoculated with approximately 6 logs of SARS-CoV-2 prepared in a soil load were disinfected within 5 min through exposure to 66.5% EtOH, 0.5% NaOCl, and 1% KMPS. The addition of mechanical wiping using DPWs impregnated with these biocides rendered the virus inactive almost immediately, with no viral transfer from the used DPW to adjacent surfaces. Carriers treated with 100 ppm of ClO2 showed a significant amount of viable virus remaining after 10 min of biocide exposure, while the virus was only completely inactivated after 10 min of treatment with 500 ppm of ClO2. Wiping SARS-CoV-2-spiked carriers with DPWs containing either concentration of ClO2 for 5 s left significant amounts of viable virus on the carriers. Furthermore, higher titers of infectious virus retained on the ClO2-infused DPWs were transferred to uninoculated carriers immediately after wiping. Overall, 66.5% EtOH, 0.5% NaOCl, and 1% KMPS appear to be highly effective biocidal agents against SARS-CoV-2, while ClO2 formulations are much less efficacious.

Synergistic effects of quaternary ammonium compounds and food additive grade calcium hydroxide on microbicidal activities at low temperatures

The microbicidal activities of mixtures of quaternary ammonium compounds (QACs) and food additive grade calcium hydroxide (FdCa(OH)₂) were evaluated in a suspension test at −20°C using an anti-freeze agent (AFA) containing methanol, or at 1°C, with varying contact time, toward avian influenza virus (AIV), Newcastle disease virus (NDV), fowl adenovirus (FAdV), avian reovirus (ARV), Salmonella Infantis (SI) and Escherichia coli (EC). At −20°C, the mixtures could inactivate AIV and NDV within 30 min, FAdV and ARV within 5 sec, and SI and EC within 3 min, respectively. AFA did not inactivate viruses and bacteria within 30 min and 10 min, respectively. At 1°C, the mixtures inactivated FAdV and ARV within 30 sec, AIV within 10 min, and NDV within 30 min. A mixture of slaked lime (SL) and QAC could inactivate FAdV and ARV within 30 sec, but could not inactivate AIV and NDV even after 60 min at 1°C. SL could not substitute FdCa(OH)₂ in order to exert the synergistic effects with QAC. Thus, QACs microbicidal activities were maintained or enhanced by adding FdCa(OH)₂. It is hence recommended to use QACs with FdCa(OH)₂, especially in the winter season.

Health Care Environmental Hygiene: New Insights and Centers for Disease Control and Prevention Guidance

Recent research has significantly clarified the impact of optimizing patient-zone environmental hygiene. New insights into the environmental microbial epidemiology of many hospital-associated pathogens, especially Clostridioides difficile, have clarified and quantified the role of ongoing occult pathogen transmission from the near-patient environment. The recent development of safe, broadly effective surface chemical disinfectants has led to new opportunities to broadly enhance environmental hygiene in all health care settings. The Centers for Disease Control and Prevention has recently developed a detailed guidance to assist all health care settings in implementing optimized programs to mitigate health care-associated pathogen transmission from the near-patient surfaces.

Comparison of the Efficacy of Disinfectant Pre-impregnated Wipes for Decontaminating Stainless Steel Carriers Experimentally Inoculated With Ebola Virus and Vesicular Stomatitis Virus

The authors evaluated four disinfectant pre-impregnated wipes (DPW) for efficacy against Ebola virus Makona variant (EBOV) and vesicular stomatitis virus (VSV), Indiana serotype. Steel carriers were inoculated with the infectious virus and then were wiped with DPW in the Wiperator instrument per ASTM E2967-15. Following the use of J-Cloth impregnated with medium (negative control wipes) or the use of activated hydrogen peroxide (AHP)-, ethanol-, sodium hypochlorite (NaOCl)-, or single or dual quaternary ammonium compound (QAC)-based DPW, virus recovery from the carriers was assayed by titration assay and by two passages on Vero E6 cells in 6-well plates. The Wiperator also enabled the measurement of potential transfer of the virus from the inoculated carrier to a secondary carrier by the DPW or control wipes. The J-Cloth wipes wetted with medium alone (no microbicidal active) removed 1.9–3.5 log₁₀ of virus from inoculated carriers but transferred ~4 log₁₀ of the wiped virus to secondary carriers. DPW containing AHP, ethanol, NaOCl, or single or dual QAC as active microbicidal ingredients removed/inactivated ~6 log₁₀ of the virus, with minimal EBOV or no VSV virus transfer to a secondary surface observed. In Ebola virus outbreaks, a DPW with demonstrated virucidal efficacy, used as directed, may help to mitigate the unintended spread of the infectious virus while performing surface cleaning.

Application of EN 16615 (4-Field Test) for the Evaluation of the Antimicrobial Activity of the Selected Commercial and Self-Made Disinfectant Wipes

The purpose of disinfectants is to reduce microorganisms on a contaminated surface and to prevent the spread of microorganisms. The relatively new EN 16615 simulates disinfection by wiping and allows for assessing the recovery of microorganisms from the surface and, importantly, the degree of spread of microorganisms when the surface is disinfected by wiping. For the first time, using this standard, the tested products in the form of commercial disinfectant wipes were compared with self-made wipes soaked in respective disinfectant liquids. The disinfected surfaces were simulated by homogeneous polyvinyl chloride plates. The studies were carried out not only with the standard, but also with clinical multidrug-resistant microbial strains. Based on the research, it can be concluded that the most effective products in the disinfection process (log₁₀ reduction of ≥5) with the shortest contact time (1 min) were products containing ethanol, propanol, and quaternary ammonium compounds (self-made wipes) and propanol (commercial wipes). The least effective products (log₁₀ reduction of <5) in terms of the contact time declared by the manufacturer were products containing ethanol and sodium hypochlorite (commercial wipes). Much better antimicrobial activity of self-made wipes was observed in comparison to the activity of the commercial wipes.

Practical recommendations for routine cleaning and disinfection procedures in healthcare institutions: a narrative review

Healthcare-associated infections (HAIs) are the most common adverse outcomes due to delivery of medical care. HAIs increase morbidity and mortality, prolong hospital stay, and are associated with additional healthcare costs. Contaminated surfaces, particularly those that are touched frequently, act as reservoirs for pathogens and contribute towards pathogen transmission. Therefore, healthcare hygiene requires a comprehensive approach whereby different strategies may be implemented together, next to targeted, risk-based approaches, in order to reduce the risk of HAIs for patients. This approach includes hand hygiene in conjunction with environmental cleaning and disinfection of surfaces and clinical equipment. This review focuses on routine environmental cleaning and disinfection including areas with a moderate risk of contamination, such as general wards. As scientific evidence has not yet resulted in universally accepted guidelines nor led to universally accepted practical recommendations pertaining to surface cleaning and disinfection, this review provides expert guidance for healthcare workers in their daily practice. It also covers outbreak situations and suggests practical guidance for clinically relevant pathogens. Key elements of environmental cleaning and disinfection, including a fundamental clinical risk assessment, choice of appropriate disinfectants and cleaning equipment, definitions for standardized cleaning processes and the relevance of structured training, are reviewed in detail with a focus on practical topics and implementation.

Is a reduction in viability enough to determine biofilm susceptibility to a biocide?

OBJECTIVE

The abundance and prevalence of dry-surface biofilms (DSBs) in hospitals constitute an emerging problem, yet studies rarely report the cleaning and disinfection efficacy against DSBs. Here, the combined impact of treatments on viability, transferability, and recovery of bacteria from DSBs has been investigated for the first time.

METHODS

Staphylococcus aureus DSBs were produced in alternating 48-hour wet-dry cycles for 12 days on AISI 430 stainless steel discs. The efficacy of 11 commercially available disinfectants, 4 detergents, and 2 contactless interventions were tested using a modified standardized product test. Reduction in viability, direct transferability, cross transmission (via glove intermediate), and DSB recovery after treatment were measured.

RESULTS

Of 11 disinfectants, 9 were effective in killing and removing bacteria from S. aureus DSBs with >4 log10 reduction. Only 2 disinfectants, sodium dichloroisocyanurate 1,000 ppm and peracetic acid 3,500 ppm, were able to lower both direct and cross transmission of bacteria (<2 compression contacts positive for bacterial growth). Of 11 disinfectants, 8 could not prevent DSB recovery for >2 days. Treatments not involving mechanical action (vaporized hydrogen peroxide and cold atmospheric plasma) were ineffective, producing <1 log10 reduction in viability, DSB regrowth within 1 day, and 100% transferability of DSB after treatment.

CONCLUSIONS

Reduction in bacterial viability alone does not determine product performance against biofilm and might give a false sense of security to consumers, manufacturers and regulators. The ability to prevent bacterial transfer and biofilm recovery after treatment requires a better understanding of the effectiveness of biocidal products.

Antibacterial and Antiviral Functional Materials: Chemistry and Biological Activity toward Tackling COVID-19-like Pandemics

The ongoing worldwide pandemic due to COVID-19 has created awareness toward ensuring best practices to avoid the spread of microorganisms. In this regard, the research on creating a surface which destroys or inhibits the adherence of microbial/viral entities has gained renewed interest. Although many research reports are available on the antibacterial materials or coatings, there is a relatively small amount of data available on the use of antiviral materials. However, with more research geared toward this area, new information is being added to the literature every day. The combination of antibacterial and antiviral chemical entities represents a potentially path-breaking intervention to mitigate the spread of disease-causing agents. In this review, we have surveyed antibacterial and antiviral materials of various classes such as small-molecule organics, synthetic and biodegradable polymers, silver, TiO2, and copper-derived chemicals. The surface protection mechanisms of the materials against the pathogen colonies are discussed in detail, which highlights the key differences that could determine the parameters that would govern the future development of advanced antibacterial and antiviral materials and surfaces.

An emerging source of plastic pollution: Environmental presence of plastic personal protective equipment (PPE) debris related to COVID-19 in a metropolitan city

The COVID-19 pandemic has resulted in an unprecedented surge of production, consumption, and disposal of personal protective equipment (PPE) including face masks, disposable gloves, and disinfectant wipes, which are often made of single use plastic. Widespread public use of these items has imposed pressure on municipalities to properly collect and dispose of potentially infectious PPE. There has been a lack of structured monitoring efforts to quantify the emerging trend of improperly disposed of PPE debris. In this study, we present a baseline monitoring survey to describe the spatial distribution of PPE debris during the COVID-19 pandemic from the metropolitan city of Toronto, Canada. Our objectives were to: (1) quantify PPE debris types among surveyed areas and; (2) identify PPE debris densities and accumulation of surveyed areas. A total of 1306 PPE debris items were documented, with the majority being disposable gloves (44%), followed by face masks (31%), and disinfecting wipes (25%). Of the face masks, 97% were designed for single use while only 3% were reusable. Of the surveyed locations, the highest daily average densities of PPE debris were recorded in the large and medium-sized grocery store parking lots and the hospital district (0.00475 items/m², 0.00160 items/m², and 0.00133 items/m² respectively). The two surveyed residential areas had the following highest PPE densities (0.00029 items/m² and 0.00027 items/m²), while the recreational trail had the lowest densities (0.00020 items/m²). Assuming a business-as-usual accumulation, an estimated 14,298 PPE items will be leaked as debris in just the surveyed areas annually. To facilitate proper disposal of PPE debris by the public we recommend development of municipal efforts to improve PPE collection methods that are informed by the described PPE waste pathways.

Establishment and utilization of an evaluation system for virucidal activity of disinfectants against a coronavirus with apparent applicability to SARS-CoV-2

Decontamination of pathogens on surfaces of substances is very important for controlling infectious diseases. In the present experiments, we tested various disinfectants in aqueous phase as well as on plastic surface carrying a viral inoculum, through dropping and wiping decontamination techniques, comparatively, so as to evaluate virucidal efficacies of those disinfectants toward an avian coronavirus (infectious bronchitis virus: IBV). We regard this evaluation system applicable to SARS-CoV-2. The disinfectants evaluated were 0.17% food additive glade calcium hydroxide (FdCa(OH)2) solution, sodium hypochlorite at 500 or 1,000 ppm of total chlorine (NaClO-500 or NaClO-1,000, respectively), NaClO at 500 ppm of total chlorine in 0.17% FdCa(OH)2 (Mix-500) and quaternary ammonium compound (QAC) diluted 500-fold in water (QAC-500). In the suspension test, all solutions inactivated IBV inoculum that contained 5% fetal bovine serum (FBS) under detectable level within 30 sec. In the carrier test, all solutions, except NaClO-500, could inactivate IBV with 0.5% FBS on a carrier to undetectable level in the wiping-sheets and wiped-carriers. We thus conclude that suspension and carrier tests should be introduced to evaluate disinfectants for the field usage, and that this evaluation system is important and workable for resultful selection of the tested disinfectants against avian coronavirus and SARS-CoV-2 on surfaces, particularly on plastic fomite.

Removal of Aerosolized Contaminants from Working Canines via a Field Wipe-Down Procedure

Evidence-based canine decontamination protocols are underrepresented in the veterinary literature. Aerosolized microbiological and chemical contaminants can pose a risk in deployment environments highlighting the need for improved canine field decontamination strategies. Prior work has established the efficacy of traditional, water-intensive methods on contaminant removal from the coat of the working canine; however, it is not known if similar reductions can be achieved with simple field expedient methods when resources are limited. The objective of this study was to measure the reduction of aerosolized contamination via a practical "wipe-down" procedure performed on working canine coats contaminated with a fluorescent, non-toxic, water-based aerosol. Disposable, lint-free towels were saturated with one of three treatments: water, 2% chlorhexidine gluconate scrub (CHX), or 7.5% povidone-iodine scrub (PVD). Both CHX and PVD were diluted at a 1:4 ratio. Treatments were randomly assigned to one of three quadrants established across the shoulders and back of commonly utilized working dog breeds (Labrador retrievers, n = 16; German shepherds, n = 16). The fourth quadrant remained unwiped, thus serving as a control. Reduction in fluorescent marker contamination was measured and compared across all quadrants. PVD demonstrated greater marker reduction compared to CHX or water in both breeds (p < 0.0001). Reduction was similar between CHX or water in Labradors (p = 0.86) and shepherds (p = 0.06). Effective wipe-down strategies using common veterinary cleansers should be further investigated and incorporated into decontamination practices to safeguard working canine health and prevent cross-contamination of human personnel working with these animals.

A review of wipes used to disinfect hard surfaces in health care facilities

BACKGROUND

Despite a plethora of wipes available for use in health care facilities, there is a paucity of articles describing wipe composition, potential interactions between wipes and disinfectants, the manner in which wipes are used, and their relative efficacy. The purpose of this article is to provide an in-depth review of wipes used for disinfection of hard surfaces in health care settings.

METHODS

Comprehensive searches of the Pubmed database and Internet were conducted, and articles published from 1953 through September 2019 and pertinent on-line documents were reviewed. Bibliographies of relevant articles were reviewed.

RESULTS

Wipes vary considerably in their composition, and the disinfectants with which they are used. With reusable dry wipes, the ratio of wipe material to disinfectant and the amount of disinfectant absorbed by the wipe and delivered to surfaces is difficult to standardize, which may affect their efficacy. The manner in which wipes are used by health care personnel is highly variable, due in part to insufficient instructions for use and inadequate education of relevant personnel.

CONCLUSIONS

Additional research is needed regarding the best practices for using different types of wipes, improved methods for educating staff, and establishing the relative efficacy of wipes in reducing environmental contamination and health care-associated infections.

Recontamination of Healthcare Surfaces by Repeated Wiping with Biocide-Loaded Wipes: "One Wipe, One Surface, One Direction, Dispose" as Best Practice in the Clinical Environment

The wiping of high-touch healthcare surfaces made of metals, ceramics and plastics to remove bacteria is an accepted tool in combatting the transmission of healthcare-associated infections (HCAIs). In practice, surfaces may be repeatedly wiped using a single wipe, and the potential for recontamination may be affected by various factors. Accordingly, we studied how the surface to be wiped, the type of fibre in the wipe and how the presence of liquid biocide affected the degree of recontamination. Experiments were conducted using metal, ceramic and plastic healthcare surfaces, and two different wipe compositions (hygroscopic and hydrophilic), with and without liquid biocide. Despite initially high removal efficiencies of >70% during initial wiping, all healthcare surfaces were recontaminated with E. coli, S. aureus and E. faecalis when wiped more than once using the same wipe. Recontamination occurred regardless of the fibre composition of the wipe or the presence of a liquid biocide. The extent of recontamination by E. coli, S. aureus and E. faecalis bacteria also increased when metal healthcare surfaces possessed a higher microscale roughness (<1 μm), as determined by Atomic Force Microscopy (AFM). The high propensity for healthcare surfaces to be re-contaminated following initial wiping suggests that a “One wipe, One surface, One direction, Dispose” policy should be implemented and rigorously enforced.

Does size matter? The impact of a small but targeted cleaning training intervention within a paediatric ward

Background

Cleaning is a critical tool for infection prevention and control, and is a key intervention for preventing healthcare associated infections (HCAIs) and controlling intermediate transmission routes between patient and environment. This study sought to identify potential areas of weakness in clinical surface cleaning, and assess the effectiveness of a staff group specific training intervention.

Observations

One-hundred hours of audit observations in a paediatric cardiac intensive care unit (CICU) assessed surface cleaning technique of healthcare staff within bedspaces. Cleaning was assessed with a 5-component bundle, with each cleaning opportunity scored out of five.

Training Intervention

Fifty hours of audit observations before and after a training intervention tested the efficacy of a staff group specific education intervention. The intervention was developed and implemented for 69% of nurses and 100% of cleaners.

Results

One hundred and eighteen cleaning opportunities were observed before training, and scored an average of 2.4. One hundred and twenty-one cleaning opportunities were observed after training and scored an average 3.0. On average, before training, each cleaning opportunity by nurses and cleaners fulfilled 2.4 and 2.5, respectively, of the 5 bundle components. Following training, this improved to 3.3 and 2.9 respectively. There was a statistically significant improvement in bundle scores for nurses (P=.004) and cleaners (P=.0003).

Conclusions

Surface wipe methods were inconsistent between all staff groups. The education based intervention resulted in a small improvement in most of the cleaning components. This study has identified how a small but targeted cleaning training intervention can have a significant (P= <.0001) impact on cleaning bundle compliance for both nurses and cleaners.

Laboratory efficacy of surface disinfection using chlorine against Vibrio cholerae

Disinfecting surfaces with chlorine is commonly conducted in cholera outbreaks to prevent ongoing fomite-based transmission, yet evidence gaps have led to contradictory guidance. In this study, we tested the efficacy of spraying and wiping chlorine on five representatives non-porous and five porous surfaces to remove Vibrio cholerae. In total, 120 disinfection tests were run in replicate on carriers inoculated with 1.02 × 10⁷-1.73 × 10⁸ V. cholerae CFU/cm². Surfaces disinfected by spraying 0.2% chlorine had >3 log reduction value (LRV) on 7/10 and 9/10 surfaces at 1 and 10 min, respectively; and 2.0% chlorine on 9/10 and 10/10 surfaces at 1 and 10 min, respectively. Surfaces disinfected by wiping 0.2% chlorine had >3 LRV on 3/10 and 7/10 surfaces at 1 and 10 min, respectively; and 2.0% chlorine on 8/10 surfaces at 1 and 10 min. We found no significant differences between chlorine types (p < 0.05), higher reductions with spraying compared to wiping (p = 0.001), and lower reductions on porous compared to non-porous surfaces (p = 0.006 spraying and p < 0.001 wiping). Our results support using 0.2% chlorine sprayed on all surfaces, or wiped on most non-heavily soiled surfaces, and a 2.0% concentration on contaminated porous surfaces; and emphasize surfaces must be visibly wetted to achieve disinfection.

Surface Wiping Test to Study Biocide -Cinnamaldehyde Combination to Improve Efficiency in Surface Disinfection

Disinfection is crucial to control and prevent microbial pathogens on surfaces. Nonetheless, disinfectants misuse in routine disinfection has increased the concern on their impact on bacterial resistance and cross-resistance. This work aims to develop a formulation for surface disinfection based on the combination of a natural product, cinnamaldehyde, and a widely used biocide, cetyltrimethylammonium bromide. The wiping method was based on the Wiperator test (ASTM E2967−15) and the efficacy evaluation of surface disinfection wipes test (EN 16615:2015). After formulation optimization, the wiping of a contaminated surface with 6.24 log₁₀ colony-forming units (CFU) of Escherichia coli or 7.10 log₁₀ CFU of Staphylococcus aureus led to a reduction of 4.35 log₁₀ CFU and 4.27 log₁₀ CFU when the wipe was impregnated with the formulation in comparison with 2.45 log₁₀ CFU and 1.50 log₁₀ CFU as a result of mechanical action only for E. coli and S. aureus, respectively. Furthermore, the formulation prevented the transfer of bacteria to clean surfaces. The work presented highlights the potential of a combinatorial approach of a classic biocide with a phytochemical for the development of disinfectant formulations, with the advantage of reducing the concentration of synthetic biocides, which reduces the potentially negative environmental and public health impacts from their routine use.

Environmental Surface Hygiene in the OR: Strategies for Reducing the Transmission of Health Care-Associated Infections

Health care-associated infections (HAIs) cost billions of dollars annually in the United States and cause patient morbidity and mortality. There is increasing evidence that environmental surfaces in the OR setting, including anesthesia work areas, can harbor pathogens that can lead to HAIs. Patient-care equipment used routinely in the OR, such as electrocardiograph wires, blood pressure cuffs, pulse oximetry probes, and monitor cables, can become contaminated with pathogens during surgical procedures; without proper cleaning and disinfection between procedures, these items pose a risk for pathogen transmission and subsequent patient infections. This article discusses the association between contaminated surfaces in the OR and the risk for HAIs. It is essential that perioperative nurses, environmental services personnel, anesthesia technicians, and anesthesia professionals properly disinfect environmental surfaces to prevent HAIs.

Assessing the Contributions of Inactivation, Removal, and Transfer of Ebola Virus and Vesicular Stomatitis Virus by Disinfectant Pre-soaked Wipes

Disinfectant pre-soaked wipes (DPW) containing activated hydrogen peroxide (AHP) or quaternary ammonium compounds (QAC) were tested using ASTM E2967-15 to determine removal, transfer, and inactivation of Ebola virus Makona variant (EBOV/Mak) and vesicular stomatitis virus (VSV) from contaminated stainless steel prototypic environmental surfaces. The infectious virus-contaminated carriers were subjected to wiping in the Wiperator per the standard. Following the use of negative control (J-Cloth)-, AHP-, or QAC-based wipes, recovery of residual infectious virus was assayed. In the case of the J-Cloth wipes (negative control), although removal of virus from inoculated carriers was extensive i.e., ~99% (1.9–3.5 log₁₀) transfer of virus by these wipes to a secondary surface amounted to ≤ 2% (~3.8 log₁₀) of the initial virus load. In the case of each DPW, >6 log₁₀ removal/inactivation of virus was observed, with limited (EBOV/Mak) or no (VSV) virus transfer observed. The efficacy of wipes for decontaminating high-touch environmental surfaces spiked with EBOV/Mak or VSV is discussed. In summary, removal of EBOV/Mak and VSV using wipes was extensive in this study. In the absence of a sufficient concentration and contact time of an appropriate microbicidal active in DPW (such as the AHP- and QAC-based DPW tested), transfer of a low, albeit significant (from an infectious unit/infectious dose perspective), quantity of infectious virus from the inoculated surface to a secondary surface was observed. In the case of Ebola virus, it is essential that a DPW with an appropriate microbicidal active, following the appropriate contact time, be used to prevent unintended transfer of infectious virus to a clean secondary surface (as observed in negative control /J-Cloth). Otherwise, there exists the possibility of dissemination of Ebola virus and the associated risk of transmission of Ebola virus disease.

Antimicrobial Efficiency and Surface Interactions of Quaternary Ammonium Compound Absorbed on Dielectric Barrier Discharge (DBD) Plasma Treated Fiber-Based Wiping Materials

The physicochemical interactions between alkyldimethylbenzylammonium chloride (ADBAC) as disinfectant and three commercial wiping materials made from 100% polyester (PET), 55%cellulose/45%PET (blend), and 100% cellulose were investigated after treatment with dielectric barrier discharge (DBD) plasma at atmospheric pressure. Wipe material type in terms of cellulose content, liquor ratio, and immersion time demonstrated a significant influence on the adsorption of ADBAC. The higher the content of cellulose in the material, the higher is the adsorption of ADBAC active ingredient. The antimicrobial tests confirm that the ADBAC adsorbed on pure cellulosic material is inactivated losing its bactericidal activity, while 100% PET and blend wipes showed good antimicrobial efficacy. XPS analysis demonstrates the strong interactions of ADBAC with the plasma-generated oxygen species in the polyester-containing wipes surface. Unexpectedly, plasma-treated blend wipe displays a reverse antimicrobial effect compared to untreated samples, performing better in Gram-negative bacteria. The best result was obtained in the plasma treated 100% polyester wipe showing an improvement of about 20% in Gram-positive bacteria and an excellent performance in Gram-negative ones. This method allows the unprecedented use of pure polyester as effective wiping material for surface disinfection eliminating the major drawback of pure polyester, its high hydrophobicity.

Clostridium Difficile: Reducing Infections Using an Evidence-Based Practice Initiative

BACKGROUND

Nosocomial Clostridium difficile (C. difficile) infections are adverse incidents that affect immunocompromised hospitalized patients. High-touch surface areas within the patient's environment are frequently overlooked and are a source of microscopic bacterial transmission.

OBJECTIVES

This article examines whether the use of a standardized protocol for cleaning high-touch surface areas would reduce the incidence of hospital-acquired C. difficile infection.

METHODS

The initiative targeted five high-touch surfaces, and nurses were educated about these findings. Baseline data on the C. difficile infection rate was collected from four specialty medical-surgical oncology units. A pilot period of the Five by Five initiative evaluated C. difficile infection rates after staff cleaning of these high-touch surfaces.

FINDINGS

This initiative accounted for a statistically significant reduction in C. difficile infections. The use of a standardized cleaning initiative was effective in reducing C. difficile infections. Nursing staff perceived that the education was easy to remember and supported efficient implementation.

Bactericidal Activity of Ready-To-Use Alcohol-Based Commercial Wipes According to EN 16615 Carrier Standard

Background: The effectiveness of ready-to-use disinfectant wipes was previously assessed in standardized suspension tests, which were inadequate because they ignored that the wipes are rubbed against a surface. Thus, we assessed the effectiveness of commercially available disinfectant wipes impregnated with an alcoholic solution according to the 16615 standard, which includes a test with mechanical action. Methods: According to the EN 16615 standard, under clean conditions, four squares (5 cm × 5 cm), placed next to one another, were marked on a test surface. Enterococcus hirae, Pseudomonas aeruginosa, and Staphylococcus aureus were inoculated on the leftmost square, and a wipe impregnated with an alcoholic solution was placed to the left of that square. Then, the wipe was pressed with a 2.5 kg weight and moved to the right and back to the left. After contact times of 1, 5, 10, or 15 min, we measured the reduction in bacterial load. Results: Alcohol-based ready-to-use commercial wipes did not show sufficient bactericidal activity at the contact times of 1, 5, 10 and 15 min. Wipes containing propan-1-ol and a mixture of propan-1-ol and propan-2-ol were active against Pseudomonas aeruginosa at the contact times of 1 min and 15 min. None of the examined wipes were active against Enterococcus hirae or Staphylococcus aureus. Conclusion: Bactericidal parameters of ready-to-use disinfectant wipes should be determined in surface tests, in addition to suspension tests, because suspension tests do not simulate the conditions under which disinfectant wipes are used in practice.

Evaluation of the virucidal efficacy of disinfectant wipes with a test method simulating practical conditions

Background

The use of disinfectant wipes in hospitals is increasing over the last years. These wipes should be able to inactivate microorganisms including viruses on environmental surfaces and to prevent their transfer to clean areas.

The European norm (EN) 16615:2015 describes a wiping process over four fields starting on the contaminated field 1 followed by fields 2–4 and back to the starting point (4-field test). This test method exclusively describes killing and transfer of vegetative bacteria and fungi by disinfectant wipes without measuring virucidal activities. Therefore, it was the aim of this study to use the existing test methodology additionally to evaluate virus inactivation by wipes.

Methods

The 4-field test was performed with four commercially available disinfectant wipes including the examination of the active solutions of these wipes with a reference wipe. Murine norovirus (MNV) as surrogate of human noroviruses, adenovirus (AdV) type 5 and polyomavirus SV40 (SV40) were chosen as test viruses.

Results

The per acetic acid (PAA)-based wipe (wipe A) was able to inactivate all three test viruses resulting in a four log₁₀ reduction on test field 1, whereas the quaternary ammonium compound (QAC)-based products (wipes B and C) failed to reach such reduction. Both QAC-based wipes were able to inactivate SV40 and only the active solution of wipe B was effective against MNV. Another wipe with 2-propanol as active ingredient (wipe D) was not able to show a sufficient efficacy against all three test viruses. There was a good agreement between the results of the wipes and the corresponding fluids showing no influence of the material of wipes.

Tests with the 2-propanol-based wipe D showed a transfer of all test viruses to the non-contaminated test fields 2–4. SV40 was additionally transferred by the QAC-based wipe C with 0.78% active ingredients to these additional fields. In all other cases no virus transfer to test fields 2–4 was observed. Finally, no virus could be detected in the PAA-based wipe A after usage in the 4-field test in contrast to the other wipes examined.

Conclusions

The successful performance of a 4-field test with viruses demonstrated that the existing wiping method with bacteria and fungi can be used in addition for measuring virucidal efficacy. The virus-inactivating properties of surface disinfectants could be evaluated therefore with a test simulating practical conditions with mechanical action resulting in more reliable data than the existing quantitative suspension tests and/or a carrier test without any mechanical action.

Artificial dry surface biofilm models for testing the efficacy of cleaning and disinfection

Dry surface biofilms (DSB) harbouring pathogens are widespread in healthcare settings, are difficult to detect and are resistant to cleaning and disinfection interventions. Here, we describe a practical test protocol to palliate the lack of standard efficacy test methods for DSB. Staphylococcus aureus DSB were produced over a 12-day period, grown with or without the presence of organic matter, and their composition and viability were evaluated. Disinfectant treatment was conducted with a modified ASTM2967-15 test and reduction in viability, transferability and biofilm regrowth post-treatment were measured. Dry surface biofilms produced over a 12-day period had a similar carbohydrates, proteins and DNA content, regardless of the presence or absence of organic matter. The combination of sodium hypochlorite (1000 ppm) and a microfiber cloth was only effective against DSB in the absence of organic load. With the increasing concerns of the uncontrolled presence of DSB in healthcare settings, the development of effective intervention model in the presence of organic load is appropriate for the testing of biocidal products, while the use of three parameters, log₁₀ reduction, transferability and regrowth, provides an accurate and practical measurement of product efficacy. SIGNIFICANCE AND IMPACT OF THE STUDY: The widespread presence of biofilms on dry surfaces in healthcare settings has been recently documented. These dry surface biofilms (DSB) present an unprecedented challenge to cleaning and disinfection processes. Here, we describe a practical efficacy protocol based on an in vitro Staphylococcus aureus DSB model. The protocol measures reduction in viability, transferability and biofilm regrowth post-treatment to provide altogether a practical assessment of product efficacy against dry surface biofilms.

Four steps to clean hospitals: LOOK, PLAN, CLEAN and DRY

BACKGROUND

Now that cleaning and decontamination are recognized as integral to infection control, it is timely to examine the process in more detail. This is because cleaning practices vary widely within healthcare districts, and it is likely that both time and energy are needlessly wasted with ill-defined duties. Furthermore, inadequate cleaning will not reduce the risk of infection but may even enhance it. The process would benefit from a systematic appraisal, with each component placed within an evidence-based and ordered protocol.

METHODS

A literary search was performed on 'hospital cleaning', focusing on manual aspects of cleaning, pathogen reservoirs and transmission, hand hygiene, staff responsibilities and patient comfort.

RESULTS

No articles providing an evidence-based practical approach to systematic cleaning in hospitals were identified. This review therefore proposes a simple four-step guide for daily cleaning of the occupied bed space. Step 1 (LOOK) describes a visual assessment of the area to be cleaned; Step 2 (PLAN) argues why the bed space needs preparation before cleaning; Step 3 (CLEAN) covers surface cleaning/decontamination; and Step 4 (DRY) is the final stage whereby surfaces are allowed to dry.

CONCLUSION

Given the lack of articles providing practical cleaning guidance, this review proposes a four-step protocol based on evidence if available, or justified where not. Each step is presented, discussed and risk-assessed. It is likely that a systematic cleaning process would reduce the risk of healthcare-associated infection for everyone, including outbreaks, in addition to heightened confidence in overall quality of care.

Candida auris Dry Surface Biofilm (DSB) for Disinfectant Efficacy Testing

Candida auris is an emerging pathogen that needs to be controlled effectively due to its association with a high mortality rate. The presence of biofilms on dry surfaces has been shown to be widespread in healthcare settings. We produced a C. auris dry surface biofilm (DSB) on stainless steel surfaces following sequential hydration and desiccation cycles for 12 days. The ASTM2967-15 was used to measure the reduction in viability of 12 commercially wipe-based disinfectants and sodium hypochlorite (1000 ppm) against C. auris DSB. We also evaluated C. auris transferability and biofilm regrowth post-treatment. A peracetic acid (3500 ppm) product and two chlorine-based products (1000 ppm available chlorine) were successful in reducing C. auris viability and delaying DSB regrowth. However, 50% of the products tested failed to decrease C. auris viability, 58% failed to prevent its transferability, and 75% did not delay biofilm regrowth. Using three different parameters to measure product efficacy provided a practical evaluation of product effectiveness against C. auris DSB. Although log10 reduction in viability is traditionally measured, transferability is an important factor to consider from an infection control and prevention point of view as it allows for determination of whether the surface is safe to touch by patients and hospital staff post-treatment.

Pathogen transfer through environment-host contact: an agent-based queueing theoretic framework

Queueing theory studies the properties of waiting queues and has been applied to investigate direct host-to-host transmitted disease dynamics, but its potential in modelling environmentally transmitted pathogens has not been fully explored. In this study, we provide a flexible and customizable queueing theory modelling framework with three major subroutines to study the in-hospital contact processes between environments and hosts and potential nosocomial pathogen transfer, where environments are servers and hosts are customers. Two types of servers with different parameters but the same utilization are investigated. We consider various forms of transfer functions that map contact duration to the amount of pathogen transfer based on existing literature. We propose a case study of simulated in-hospital contact processes and apply stochastic queues to analyse the amount of pathogen transfer under different transfer functions, and assume that pathogen amount decreases during the inter-arrival time. Different host behaviour (feedback and non-feedback) as well as initial pathogen distribution (whether in environment and/or in hosts) are also considered and simulated. We assess pathogen transfer and circulation under these various conditions and highlight the importance of the nonlinear interactions among contact processes, transfer functions and pathogen demography during the contact process. Our modelling framework can be readily extended to more complicated queueing networks to simulate more realistic situations by adjusting parameters such as the number and type of servers and customers, and adding extra subroutines.

Improving Cleaning and Disinfection of High-Touch Surfaces in Intensive Care during Carbapenem-Resistant Acinetobacter baumannii Endemo-Epidemic Situations

Aims: High-touch surfaces cleaning and disinfection require the adoption of effective and proper executed protocols, especially during carbapenem-resistant Acinetobacter baumannii (CRAB) endemo-epidemic situations. We evaluated the effectiveness and residual disinfectant activity of disposable pre-impregnated wipes (Modified Operative Protocol, MOP) in reducing environmental bioburden versus a two-step Standard Operative Protocol (SOP) in a 12-bed Intensive Care Unit. Methods: Five high-touch surfaces were cleaned and disinfected either according to the SOP (alcohol-based cleaning and chlorine-based disinfection) or using quaternary ammonium compounds-based disposable wipes (MOP). Sampling was performed before each procedure and at 0.5, 2.5, 4.5 and 6.5 h after (560 sites). Total viable count (TVC) was evaluated according to Italian hygiene standard (<50 CFU/24 cm²). Clinical and environmental CRAB strains isolated were genotyped. Results: On non-electromedical surfaces the difference between TVC before procedure and at each of the following times was significant only for the MOP (p < 0.05, Wilcoxon test). Using the MOP, only 7.4% (10/135) of sites showed TVC >50 CFU/24 cm² (hygiene failures) versus 18.9% (25/132) after SOP (p < 0.05, Fisher’s Exact test). On infusion pumps a higher number of hygiene failures was observed after the SOP (7/44, 15.9%) compared with the MOP (4/45, 8.9%). Genotyping highlighted a common source of infection. Conclusion: On high-touch surfaces, the use of disposable wipes by in-house auxiliary nurses may represent a more effective alternative to standard cleaning and disinfection procedure performed by outsourced cleaning services, showing effectiveness in reducing microbial contamination and residual disinfection activity up to 6.5 h.

Impact of antimicrobial wipes compared with hypochlorite solution on environmental surface contamination in a health care setting: A double-crossover study

OBJECTIVE

Antimicrobial wipes are increasingly used in health care settings. This study evaluates, in a clinical setting, the efficacy of sporicidal wipes versus a cloth soaked in a 1,000 ppm chlorine solution.

INTERVENTION

A double-crossover study was performed on 2 different surgical and cardiovascular wards in a 1,000-bed teaching hospital over 29 weeks. The intervention period that consisted of surface decontamination with the preimpregnated wipe or cloth soaked in chlorine followed a 5-week baseline assessment of microbial bioburden on surfaces. Environmental samples from 11 surfaces were analyzed weekly for their microbial content.

RESULTS

A total of 1,566 environmental samples and 1,591 ATP swabs were analyzed during the trial. Overall, there were significant differences in the recovery of total aerobic bacteria (P < .001), total anaerobic bacteria (P < .001), and ATP measurement (P < .001) between wards and between the different parts of the crossover study. Generally, the use of wipes produced the largest reduction in the total aerobic and anaerobic counts when compared with the baseline data or the use of 1,000 ppm chlorine. Collectively, the introduction of training plus daily wipe disinfection significantly reduced multidrug-resistant organisms recovered from surfaces. Reversion to using 1,000 ppm chlorine resulted in the number of sites positive for multidrug-resistant organisms rising again.

CONCLUSIONS

This double-crossover study is the first controlled field trial comparison of using preimpregnated wipes versus cotton cloth dipped into a bucket of hypochlorite to decrease surface microbial bioburden. The results demonstrate the superiority of the preimpregnated wipes in significantly decreasing microbial bioburden from high-touch surfaces.

Impact of test protocols and material binding on the efficacy of antimicrobial wipes

BACKGROUND

The use of effective cleaning/disinfectant products is important to control pathogens on healthcare surfaces. With the increasing number of wipe products available, there is a concern that combination of a formulation with the wrong material will decrease the efficacy of the product. This study aimed to use a range of efficacy test protocols to determine the efficacy of four formulations before and after binding to three commonly used wiping materials.

METHODS

Two quaternary ammonium (QAC)-based products, one hydrogen-peroxide-based product and one neutral cleaner were combined with microfibre, cotton or non-woven materials and tested for efficacy against Pseudomonas aeruginosa and Staphylococcus aureus with two surface tests (ASTM E2197-17 and EN13697-15) and two 'product' tests (ASTM E2967-15 and EN16615-15).

FINDINGS

Overall, the impact of using different materials on formulation efficacy was limited, except for an alkyl(C_12-16)dimethylbenzylammonium chloride-based product used at 0.5% v/v. The hydrogen peroxide product was the most efficacious regardless of the material used. The results from wipe test ASTM E2967-15 were consistent with those from the surface tests, but not with EN16615-15 which was far less stringent.

CONCLUSIONS

The use of different wiping cloth materials may not impact severely on the efficacy of potent disinfectants, despite the absorption of different volumes of formulation by the materials. QAC-based formulations may be at higher risk when a low concentration is used. There were large differences in efficacy depending on the standard test performed, highlighting the need for more stringency in choosing the test to make a product claim on label.

A new sampling algorithm demonstrates that ultrasound equipment cleanliness can be improved

BACKGROUND

Australia has established guidelines on cleaning for reusable ultrasound probes and accompanying equipment. This is a preliminary study investigating cleanliness standards of patient-ready ultrasound equipment in 5 separate health care facilities within a major city.

METHODS

The cleanliness was assessed using rapid adenosine triphosphate (ATP) testing used with a sampling algorithm which mitigates variability normally associated with ATP testing. Each surface was initially sampled in duplicate for relative light units (RLUs) and checked for compliance with literature recommended levels of cleanliness (<100 RLUs). Triplicate sampling was undertaken where necessary. A cleaning intervention step (CIS) followed using a disposable detergent wipe, and the surface was retested for ATP.

RESULTS

There were 253 surfaces tested from the 5 health care facilities with 26% (66/253) demonstrating either equivocal or apparent lack of cleanliness. The CIS was conducted on 148 surfaces and demonstrated that for >91% (135/148) of surfaces, the cleaning standards could be improved significantly (P > .001). For 6% (9/148) of devices and surfaces, the CIS needed to be repeated at least once to achieve the intended level of cleanliness (<25 RLUs).

CONCLUSIONS

This study indicates that ATP testing is an effective, real-time, quality assurance tool for cleanliness monitoring of ultrasound probes and associated equipment.

AVALIAÇÃO DA EFICIÊNCIA DA LIMPEZA E DESINFECÇÃO DE SUPERFÍCIES EM UMA UNIDADE BÁSICA DE SAÚDE

RESUMO Objetivo: avaliar o efeito de intervenções educativasna limpeza e desinfecção de superfícies em uma unidade básica de saúde. Métodos: trata-se de um estudo prospectivo, analítico com abordagem quantitativa. O estudo foi realizado em uma unidade básica de saúde, onde atuam duas equipes da Estratégia de Saúde da Família. Optou-se por avaliar a limpeza e desinfecção das superfícies: carrinho de curativo, balcão da recepção, mesa ginecológica, maca do paciente e mesa de consulta de enfermagem, utilizando-se dos métodos de monitoramento: avaliação visual, contagem de unidades formadoras de colônias e mensuração de adenosina trifosfato. Utilizaram-se, para a análise estatística, o teste de postos de Wilcoxon e o teste de Mann-Whitney, considerou-se nível de significância de 5% ou (p<0,05). Resultados: obteve-se um total de 720 avaliações realizadas ao término de todas as fases. Observou-se na fase I uma taxa de reprovação de 57,5%, 20,0% e 90,0%; após a intervenção educativa, os quantitativos de reprovação em curto prazo diminuíram para 0,0%, 2,5,0% e 50,0% (dados da fase III) e, em longo prazo, para 5,0%, 0,0% e 65% (dados da fase IV) para os métodos visual, adenosina trifosfato e cultura, respectivamente. A inspeção visual foi o método que apresentou maior frequência de superfícies reprovadas nas fases I e IV. Conclusão: houve redução da carga microbiana e valores das leituras de adenosina trifosfato; embora essa redução não tenha sido estatisticamente significativa em todas as superfícies. Constatou-se que a intervenção educativa foi eficiente.