Pathogen transfer and high variability in pathogen removal by detergent wipes

Exploring the bactericidal efficacy of a new potassium monopersulphate-based disinfectant

BACKGROUND

Staphylococcus aureus and Klebsiella pneumoniae are common pathogens responsible for hospital-acquired infections. Both species can survive on surfaces following desiccation and form dry surface biofilms (DSB), which complicates the disinfection process.

AIM

To evaluate the efficacy of an innovative potassium monopersulphate-based nanotechnology formulation (MPS) against both planktonic and sessile S. aureus and K. pneumoniae.

METHODS

The bactericidal efficacy of MPS was tested in comparison with sodium hypochlorite (NaOCl) and didecyldimethylammonium chloride (DDAC), which served as controls. The assessment was performed against planktonic bacteria, hydrated biofilm, and dry surface biofilm (DSB) using standard suspension and carrier tests. Scanning electron microscopy (SEM) was employed to identify any gross structural damage.

FINDINGS

MPS (2% w/v) achieved a ≥4 log10 reduction in K. pneumoniae with a short contact time, regardless of the test protocol. S. aureus proved more resilient, but the introduction of wiping reduced the contact time needed to achieve a 4 log10 reduction from 15 to 5 minutes. SEM analysis revealed gross structural damage in both species following MPS treatment. The other disinfectants tested were also bactericidal, achieving ≥4 log10 reduction within 1-5 minutes, with the exception of DDAC against hydrated biofilms.

CONCLUSIONS

The potassium monopersulphate-based formulation was found to be an effective bactericide, including against dry surface biofilms (DSB). Its efficacy compares favourably with other biocides commonly used in healthcare settings, and its biodegradability makes it a promising candidate for further development. However, optimisation of the mechanical removal process will be essential to enhance MPS efficacy in practical applications.

Compositional factors driving antibacterial efficacy in healthcare wet wipe products

Healthcare-associated infections represent a persistent global pathogenic challenge, with surface contamination serving as a critical transmission vector. Antibacterial wet wipes are widely used in public health service settings, but their effectiveness varies depending on their composition and design. Evaluating existing products based on objective criteria provides a valuable foundation for enhancing future functional wet wipe formulations. In this study, four compositionally distinct proprietary antimicrobial wet wipes were assessed using objective criteria to provide a foundation for designing functional and biodegradable wet wipe formulations with enhanced properties. The mechanical properties, chemical composition, surface tension, disinfectant release, and morphological structure of four widely used wet wipe products in UK and European healthcare settings were evaluated. These products are anonymised as HP (containing oxidizing agents), BDB, DPA, and ADM (based on quaternary ammonium compounds). Antibacterial performance was tested according to EN 16615, EN 13727, and ASTM E2967 standards (suspension and wiperator-based methods) using contact times of 30 and 60 s, against E. coli, S. aureus, MRSA, and A. baumannii. The BDB product underperformed in the analysis based on the EN 16615 standard, particularly at the short contact time, where it was ineffective against E. coli and S. aureus. In contrast, HPE, DPA, and ADM products demonstrated high efficiency, achieving >5 Log bacterial reduction within 60 s for all tested strains. The ADM product demonstrated superior antibacterial performance, eliminating A. baumannii in the shortest contact time and avoiding spread of bacteria to clean surfaces. Our findings demonstrate a correlation between the liquid release rate of the wipe and the biocidal agents used, with effectiveness in reducing bacterial viability on surfaces. This research establishes a framework for optimizing disinfectant wipe design by emphasizing the importance of material properties and disinfectant formulation in determining overall effectiveness.

Hand and environmental hygiene: respective roles for MRSA, multi-resistant gram negatives, Clostridioides difficile, and Candida spp

Healthcare-associated infections (HAIs) caused by multidrug-resistant organisms (MDROs) represent a global threat to human health and well-being. Because transmission of MDROs to patients often occurs via transiently contaminated hands of healthcare personnel (HCP), hand hygiene is considered the most important measure for preventing HAIs. Environmental surfaces contaminated with MDROs from colonized or infected patients represent an important source of HCP hand contamination and contribute to transmission of pathogens. Accordingly, facilities are encouraged to adopt and implement recommendations included in the World Health Organization hand hygiene guidelines and those from the Society for Healthcare Epidemiology of America/Infectious Diseases Society of America/Association for Professionals in Infection Control and Epidemiology. Alcohol-based hand rubs are efficacious against MDROs with the exception of Clostridiodes difficile, for which soap and water handwashing is indicated. Monitoring hand hygiene adherence and providing HCP with feedback are of paramount importance. Environmental hygiene measures to curtail MDROs include disinfecting high-touch surfaces in rooms of patients with C. difficile infection daily with a sporicidal agent such as sodium hypochlorite. Some experts recommend also using a sporicidal agent in rooms of patients colonized with C. difficile, and for patients with multidrug-resistant Gram-negative bacteria. Sodium hypochlorite, hydrogen peroxide, or peracetic acid solutions are often used for daily and/or terminal disinfection of rooms housing patients with Candida auris or other MDROs. Products containing only a quaternary ammonium agent are not as effective as other agents against C. auris. Portable medical equipment should be cleaned and disinfected between use on different patients. Detergents are not recommended for cleaning high-touch surfaces in MDRO patient rooms, unless their use is followed by using a disinfectant. Facilities should consider using a disinfectant instead of detergents for terminal cleaning of floors in MDRO patient rooms. Education and training of environmental services employees is essential in assuring effective disinfection practices. Monitoring disinfection practices and providing personnel with performance feedback using fluorescent markers, adenosine triphosphate assays, or less commonly cultures of surfaces, can help reduce MDRO transmission. No-touch disinfection methods such as electrostatic spraying, hydrogen peroxide vapor, or ultraviolet light devices should be considered for terminal disinfection of MDRO patient rooms. Bundles with additional measures are usually necessary to reduce MDRO transmission.

Impact of terminal cleaning in rooms previously occupied by patients with healthcare-associated infections

Healthcare associated infections (HAIs) are costly but preventable. A limited understanding of the effects of environmental cleaning on the riskiest HAI associated pathogens is a current challenge in HAI prevention. This project aimed to quantify the effects of terminal hospital cleaning practices on HAI pathogens via environmental sampling in three hospitals located throughout the United States. Surfaces were swabbed from 36 occupied patient rooms with a laboratory-confirmed, hospital- or community-acquired infection of at least one of the four pathogens of interest (i.e., Acinetobacter baumannii (A. baumannii), methicillin resistant Staphylococcus aureus (MRSA), vancomycin resistant Enterococcus faecalis/faecium (VRE), and Clostridioides difficile (C. difficile)). Six nonporous, high touch surfaces (i.e., chair handrail, bed handrail, nurse call button, desk surface, bathroom counter near the sink, and a grab bar near the toilet) were sampled in each room for Adenosine Triphosphate (ATP) and the four pathogens of interest before and after terminal cleaning. The four pathogens of interest were detected on surfaces before and after terminal cleaning, but their levels were generally reduced. Overall, C. difficile was confirmed on the desk (n = 2), while MRSA (n = 24) and VRE (n = 25) were confirmed on all surface types before terminal cleaning. After cleaning, only MRSA (n = 6) on bed handrail, chair handrail, and nurse call button and VRE (n = 5) on bathroom sink, bed handrail, nurse call button, toilet grab bar, and C. difficile (n = 1) were confirmed. At 2 of the 3 hospitals, pathogens were generally reduced by >99% during terminal cleaning. One hospital showed that VRE increased after terminal cleaning, MRSA was reduced by 73% on the nurse call button, and VRE was reduced by only 50% on the bathroom sink. ATP detections did not correlate with any pathogen concentration. This study highlights the importance of terminal cleaning and indicates room for improvement in cleaning practices to reduce surface contamination throughout hospital rooms.

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.

Antibacterial and antibiofilm activities of iodinated hydrocarbons against Vibrio parahaemolyticus and Staphylococcus aureus

Food-related illnesses have become a growing public concern due to their considerable socioeconomic and medical impacts. Vibrio parahaemolyticus and Staphylococcus aureus have been implicated as causative organisms of food-related infections and poisoning, and both can form biofilms which confer antibiotic resistance. Hence, the need for continuous search for compounds with antibiofilm and antivirulence properties. In this study, 22 iodinated hydrocarbons were screened for their antibiofilm activity, and of these, iodopropynyl butylcarbamate (IPBC) was found to effectively control biofilm formation of both pathogens with a MIC of 50 µg/mL which was bactericidal to V. parahaemolyticus and S. aureus. Microscopic studies confirmed IPBC inhibits biofilm formation of both bacteria and also disrupted their mixed biofilm formation. Furthermore, IPBC suppressed virulence activities such as motility and hemolytic activity of V. parahaemolyticus and the cell surface hydrophobicity of S. aureus. It exhibited a preservative potential against both pathogens in a shrimp model. IPBC disrupted the cell membrane of S. aureus and V. parahaemolyticus and differentially affected gene expressions related to biofilm formation and virulence. Additionally, it displayed broad-spectrum antibiofilm activities against other clinically relevant pathogens. These findings indicate IPBC offers a potential means of controlling infections mediated by Vibrio and Staphylococcus biofilms.

Evaluation of temperature, drying time and other determinants for the recovery of Gram-negative bacterial pathogens in disinfectant efficacy testing

BACKGROUND

In the clinical setting, surface disinfection is an important measure to reduce the risk of cross transmission of micro-organisms and the risk of nosocomial infections. Standardized methods can be used to evaluate disinfection procedures, as well as the effectiveness of the active ingredients used for disinfection. However, despite standardization, the results of such methodologies are still determined by several factors, and incorrect results may lead to invalid assumptions about the effectiveness of a disinfectant, posing significant health risks for patients and health personnel.

AIM

The objective of this study was to evaluate several determinants for the recovery of Pseudomonas aeruginosa and other test organisms to establish their influence on the results of standardized disinfection methodologies, and to find Gram-negative strains that can be used as suitable replacements for P. aeruginosa.

METHODS

The effects of inoculum application method, drying time, temperature and carrier material on the survival and recovery of the test organisms were evaluated using Student's t-test, one-way analysis of variance and Tukey's multiple comparison test.

FINDINGS AND CONCLUSIONS

Temperature, drying time, application method and carrier material were found to affect the recovery of P. aeruginosa cells significantly, and therefore influence the outcome of the methodologies used. This study also showed thatP. aeruginosa could be replaced with the Gram-negative species Acinetobacter baumannii, a test organism used in many standardized methodologies, which responds better under the same circumstances and has a behaviour similar to that of P. aeruginosa in disinfectant efficacy tests.

Klebsiella pneumoniae survives on surfaces as a dry biofilm

BACKGROUND

Dry surface biofilms (DSB) are widespread in healthcare settings presenting a challenge to cleaning and disinfection. Klebsiella pneumoniae has been a focus of attention due to antibiotic resistance and the emergence of hypervirulent strains. Few studies have demonstrated K pneumoniae survival on surfaces following desiccation.

METHODS

DSB were formed over 12 days. Bacterial culturability and transfer were investigated following DSB incubation up to 4 weeks. Bacterial viability in DSB was investigated with live/dead staining using flow cytometry.

RESULTS

K pneumoniae formed mature DSB. After 2 and 4 weeks of incubation, transfer from DSB was low (<55%) and reduced further (<21%) following wiping. Culturability at 2 and 4 weeks varied although viability remained high indicating viable but non culturable state (VBNC).

DISCUSSION

K pneumoniae was removed from surfaces by mechanical wiping as shown with DSB of other species. Although culturability was reduced over time, bacteria remained viable up to 4 weeks incubation, proving the need for robust cleaning regimens.

CONCLUSIONS

This is the first study confirming K pneumoniae survival on dry surfaces as a DSB. The presence of VBNC bacteria indicated that K pneumoniae can for extended periods, raising questions about its persistence on surfaces.

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.

Disinfectants against SARS-CoV-2: A Review

The pandemic due to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has emerged as a serious global public health issue. Besides the high transmission rate from individual to individual, indirect transmission from inanimate objects or surfaces poses a more significant threat. Since the start of the outbreak, the importance of respiratory protection, social distancing, and chemical disinfection to prevent the spread of the virus has been the prime focus for infection control. Health regulatory organizations have produced guidelines for the formulation and application of chemical disinfectants to manufacturing industries and the public. On the other hand, extensive literature on the virucidal efficacy testing of microbicides for SARS-CoV-2 has been published over the past year and a half. This review summarizes the studies on the most common chemical disinfectants and their virucidal efficacy against SARS-CoV-2, including the type and concentration of the chemical disinfectant, the formulation, the presence of excipients, the exposure time, and other critical factors that determine the effectiveness of chemical disinfectants. In this review, we also critically appraise these disinfectants and conduct a discussion on the role they can play in the COVID-19 pandemic.

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.

The efficiency of cleaning in intensive care units: A systematic review

OBJECTIVES

This review aims to analyze the studies on cleaning practices and the efficiency of the cleaning carried out in environments that have a great risk of resistant microorganism infection, such as intensive care units.

METHODS

In this study, a retrospective literature review was undertaken of the relevant publications between the years 2005 and 2020, using the keywords "Cross Infection, Infection Control, Multidrug-Resistant Bacteria, Intensive Care, Room Cleaning, Environmental Cleaning, Hospital-Associated Infection"; using the international databases Pubmed, CINAHL and EBSCO and domestic database ULAKBIM on search engines. Titles and abstracts of all relevant articles found on electronic searches were reviewed by the researchers independently. The Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guideline and Patient, Intervention, Comparison, Outcomes, Study design model were used in analysing the studies.

RESULTS

The selected studies were reviewed in four main categories: Materials used in cleaning, the period between taking environmental samples, cleaning methods, and the efficiency of cleaning. Among the studies included herein, eight were randomized controlled trials, three were retrospective intervention studies, two were case-control studies and one was a retrospective cohort study.

CONCLUSIONS

Today, the assessment of cleaning in environments can be evaluated by different methods, but there are advantages and disadvantages of these methods. Therefore, in the relevant literature, it is suggested that cleaning must be evaluated by several methods, not only one. Also, training the staff that carries out the cleaning and rewarding correct behavior by giving feedback are important approaches to increase the efficiency of cleaning. It is suggested that cleaning must be carried out every day, regularly with effective methods and equipment; frequency of cleaning during epidemics must be increased, institutions must prepare cleaning manuals according to evidence-based guidelines that are recognized at an international level.

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.

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.

Using a simplified ATP algorithm to improve data reliability and improve cleanliness standards for surface and medical device hygiene

BACKGROUND

An algorithm has been improved to mitigate variability in cleanliness measurements of various surfaces using rapid Adenosine Triphosphate (ATP) testing. A cleaning intervention step (CIS) verifies the cleanability of those surfaces.

METHODS

ATP testing was performed on surfaces which were pre-approved as "clean" and ready for re-use. Adjacent (duplicate) ATP sampling was undertaken on 421 environmental surfaces, medical devices and other implements. The CIS was conducted on 270 surfaces using an aseptic technique and disposable cleaning wipes.

RESULTS

The two initial ATP results were plotted against each other with a 100 RLU threshold grading the results as clean (2x < 100RLU), dirty (2x > 100RLU) or equivocal (1x < 100RLU and 1x > 100RLU). Of the surfaces sampled, 68.5 % were clean (288/421), 13.5 % were dirty (57/421) and 18 % were equivocal (76/421). The duplicate testing demonstrated a false negative rate of 10 % (44/421) where the first swab was <100 RLU and the second swab >100 RLU. For the equivocal group, the gap between the two swabs was >100 RLU for 7.5 % of surfaces (33/421). The CIS was conducted on 270 of the surfaces tested and showed that cleaning could be improved (P=<0.001) on 88.5 % of surfaces (239/270).

CONCLUSION

The simplified ATP testing algorithm provides real-time discrimination between surface cleanliness levels and improved certainty over surface hygiene. The duplicate swab sampling approach mitigates uncontrolled variability in the results and the CIS provides a nuanced understanding of the measurable cleanliness of any surface.

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.

The efficiency of cleaning in intensive care units: A systematic review

OBJECTIVES

This review aims to analyze the studies on cleaning practices and the efficiency of the cleaning carried out in environments that have a great risk of resistant microorganism infection, such as intensive care units.

METHODS

In this study, a retrospective literature review was undertaken of the relevant publications between the years 2005 and 2020, using the keywords "Cross Infection, Infection Control, Multidrug-Resistant Bacteria, Intensive Care, Room Cleaning, Environmental Cleaning, Hospital-Associated Infection"; using the international databases Pubmed, CINAHL and EBSCO and domestic database ULAKBIM on search engines. Titles and abstracts of all relevant articles found on electronic searches were reviewed by the researchers independently. The Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guideline and Patient, Intervention, Comparison, Outcomes, Study design model were used in analysing the studies.

RESULTS

The selected studies were reviewed in four main categories: Materials used in cleaning, the period between taking environmental samples, cleaning methods, and the efficiency of cleaning. Among the studies included herein, eight were randomized controlled trials, three were retrospective intervention studies, two were case-control studies and one was a retrospective cohort study.

CONCLUSIONS

Today, the assessment of cleaning in environments can be evaluated by different methods, but there are advantages and disadvantages of these methods. Therefore, in the relevant literature, it is suggested that cleaning must be evaluated by several methods, not only one. Also, training the staff that carries out the cleaning and rewarding correct behavior by giving feedback are important approaches to increase the efficiency of cleaning. It is suggested that cleaning must be carried out every day, regularly with effective methods and equipment; frequency of cleaning during epidemics must be increased, institutions must prepare cleaning manuals according to evidence-based guidelines that are recognized at an international level.

Impact of environmental cleaning on the colonization and infection rates of multidrug-resistant Acinetobacter baumannii in patients within the intensive care unit in a tertiary hospital

Objective

To continuously evaluate the effect of environmental cleaning and hand hygiene compliance on the colonization and infection rates of multidrug-resistant Acinetobacter baumannii (MDR-AB) in the patients within an intensive care unit (ICU).

Methods

Environmental cleaning on the high-touch clinical surfaces (HTCS) within a comprehensive ICU was evaluated through monitoring fluorescent marks when the overall compliance with hand hygiene during 2013–2014 was monitored. Meanwhile, samples from the HTCS and inpatients were collected and sent for bacterial culture and identification. The drug susceptibility testing was further implemented to monitor the prevalence of MDR-AB. The genetic relatedness of MDR-AB collected either from the HTCS or inpatients was analyzed by pulsed field gel electrophoresis (PFGE) when an outbreak was doubted.

Results

The overall compliance with hand hygiene remained relatively stable during 2013–2014. Under this circumstance, the clearance rate of fluorescence marks on the environmental surfaces within ICUs significantly increased from 21.9 to 85.7%, and accordingly the colonization and infection rates of MDR-AB decreased from 16.5 to 6.6‰ and from 7.4 to 2.8‰, respectively, from the beginning to the end of 2013. However, during 2014, because of frequent change and movement of environmental services staff, the clearance rate of fluorescence marks decreased below 50.0%, and the overall colonization and infection rates of MDR-AB correspondingly increased from 9.1 to 11.1‰ and from 1.5 to 3.9‰, respectively. PFGE displayed a high genetic relatedness between the MDR-AB strains analyzed, indicating a dissemination of MDR-AB during the surveillance period.

Conclusion

For the easily disseminated MDR-AB within ICUs, the clearance rate of fluorescence labeling on HTCS is negatively correlated with the hospital infection rate of MDR-AB. Such an invisible fluorescence labelling is an effective and convenient method to continuously monitor cleanness of medical environment within hospitals.

Environmental cleaning and disinfection of hospital rooms: A nationwide survey

BACKGROUND

As an important reservoir for hospital-acquired infections, environmental surfaces have long been targeted by interventions to improve cleaning and disinfection. Differences in disinfection practices across US hospitals, however, are still unclear.

METHODS

We conducted a nationwide survey of environmental services (EVS) personnel in the United States regarding their environmental surface disinfection practices from January 2019 to June 2019. We developed and pilot tested the survey in conjunction with EVS specialists. Survey questions inquired about choices of disinfectants and cleaning equipment during daily and terminal disinfection of both contact isolation and non-contact isolation rooms. We contacted 273 EVS personnel by phone and email to participate in the survey.

RESULTS

Fourty-seven EVS personnel representing different hospitals from 26 US states were included in the analysis. Hypochlorite (bleach) and quaternary ammonium compounds were the most frequently used disinfectants. Most respondents reported using microfiber-based cloths and mops to carry out disinfection. High-touch surfaces in contact isolation rooms were frequently disinfected using bleach (81%, n = 38); floors, however, were not disinfected as frequently in patient rooms. The vast majority of respondents reported use of sporicidal disinfectants for contact isolation rooms but not regular rooms.

CONCLUSIONS

While frequently used to disinfectant contact isolation rooms, sporicidal agents are rarely used to disinfect regular rooms. Patient room floors are inconsistently disinfected compared to high-touch surfaces.

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.

Effect of Exposure to Chlorhexidine Residues at "During Use" Concentrations on Antimicrobial Susceptibility Profile, Efflux, Conjugative Plasmid Transfer, and Metabolism of Escherichia coli

There is no standardized protocol to predict the concentration levels of microbicides that are left on surfaces as a result of the use of these products, and there is no standardized method to predict the potential risk that such levels pose to emerging antibacterial resistance. The ability to distinguish between selection and adaption processes for antimicrobial resistance in bacteria and the impact of different concentrations of microbicide exposure have not been fully investigated to date. This study considers the effect of exposure to a low concentration of chlorhexidine digluconate (CHX) on selected phenotypes of Escherichia coli and relates the findings to the risk of emerging antimicrobial resistance. A concentration of 0.006 mg/ml CHX is a realistic "during use" exposure concentration measured on surfaces. At this concentration, it was possible for CHX-susceptible bacteria to survive, adapt through metabolic alterations, exhibit a transient decrease in antimicrobial susceptibility, and express stable clinical cross-resistance to front-line antibiotics. Efflux activity was present naturally in tested isolates, and it increased in the presence of 0.00005 mg/ml CHX but ceased with 0.002 mg/ml CHX. Phenotypic microarray assays highlighted a difference in metabolic regulation at 0.00005 mg/ml and 0.002 mg/ml CHX; more changes occurred after growth with the latter concentration. Metabolic phenotype changes were observed for substrates involved with the metabolism of some amino acids, cofactors, and secondary metabolites. It was possible for one isolate to continue transferring ampicillin resistance in the presence of 0.00005 mg/ml CHX, whilst 0.002 mg/ml CHX prevented conjugative transfer. In conclusion, E. coli phenotype responses to CHX exposure are concentration dependent, with realistic residual CHX concentrations resulting in stable clinical cross-resistance to antibiotics.

Behavioral strategies for reducing disease transmission in the workplace

The coronavirus pandemic highlighted that workplaces may serve as a hub of disease transmission if proper precautions are not enacted. The Centers for Disease Control recommends several strategies for decreasing the spread of illnesses in the workplace, including a) promoting proper hand hygiene, b) cleaning and sanitizing the work area, c) encouraging sick employees to stay home, d) personal protective equipment, and, e) social distancing. Research suggests that instructions are often not sufficient to change work behaviors, and behavioral interventions may be needed. Thus, the present paper reviews existing research that informs the implementation of behavioral strategies to reduce the spread of disease in the workplace, and makes recommendations for organizations to protect employees, clients, and customers. Intervention components such as training, prompts, the reduction of response effort, clear workplace policies, feedback, and consequences are discussed, and practical recommendations and suggestions for future research are provided.

Cross-contamination by disinfectant towelettes varies by product chemistry and strain

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.

Alternative Methods of Sterilization in Dental Practices Against COVID-19

SARS-CoV-2, and several other microorganisms, may be present in nasopharyngeal and salivary secretions in patients treated in dental practices, so an appropriate clinical behavior is required in order to avoid the dangerous spread of infections. COVID-19 could also be spread when patients touches a contaminated surface with infected droplets and then touch their nose, mouth, or eyes. It is time to consider a dental practice quite similar to a hospital surgery room, where particular attention should be addressed to problems related to the spreading of infections due to air and surface contamination. The effectiveness of conventional cleaning and disinfection procedures may be limited by several factors; first of all, human operator dependence seems to be the weak aspect of all procedures. The improvement of these conventional methods requires the modification of human behavior, which is difficult to achieve and sustain. As alternative sterilization methods, there are some that do not depend on the operator, because they are based on devices that perform the entire procedure on their own, with minimal human intervention. In conclusion, continued efforts to improve the traditional manual disinfection of surfaces are needed, so dentists should consider combining the use of proper disinfectants and no-touch decontamination technologies to improve sterilization procedures.

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.

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.

Microbial Community Profiling in Intensive Care Units Expose Limitations in Current Sanitary Standards

Hospital-associated infections (HAIs) are a leading cause of morbidity and mortality in intensive care units (ICUs) and neonatal intensive care units (NICUs). Organisms causing these infections are often present on surfaces around the patient. Given that microbiota may vary across different ICUs, the HAI-related microbial signatures within these units remain underexplored. In this study, we use deep-sequencing analyses to explore and compare the structure of bacterial communities at inanimate surfaces of the ICU and NICU wards of The Medical School Clinics Hospital (Brazil). The data revealed that NICU presents higher biodiversity than ICU and surfaces closest to the patient showed a peculiar microbiota, distinguishing one unit from the other. Several facultative anaerobes or obligate anaerobes HAI-related genera were classified as biomarkers for the NICU, whereas Pseudomonas was the main biomarker for ICU. Correlation analyses revealed a distinct pattern of microbe-microbe interactions for each unit, including bacteria able to form multi-genera biofilms. Furthermore, we evaluated the effect of concurrent cleaning over the ICU bacterial community. The results showed that, although some bacterial populations decreased after cleaning, various HAI-related genera were quite stable following sanitization, suggesting being well-adapted to the ICU environment. Overall, these results enabled identification of discrete ICU and NICU reservoirs of potentially pathogenic bacteria and provided evidence for the presence of a set of biomarkers genera that distinguish these units. Moreover, the study exposed the inconsistencies of the routine cleaning to minimize HAI-related genera contamination.

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.

Best practices for disinfection of noncritical environmental surfaces and equipment in health care facilities: A bundle approach

Over the past decade, there is excellent evidence in the scientific literature that contaminated environmental surfaces and noncritical patient care items play an important role in the transmission of several key health care-associated pathogens including methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Acinetobacter, norovirus, and Clostridium difficile. Thus, surface disinfection of noncritical environmental surfaces and medical devices is one of the infection prevention strategies to prevent pathogen transmission. This article will discuss a bundle approach to facilitate effective surface cleaning and disinfection in health care facilities. A bundle is a set of evidence-based practices, generally 3-5, that when performed collectively and reliably have been proven to improve patient outcomes. This bundle has 5 components and the science associated with each component will be addressed. These components are: creating evidence-based policies and procedures; selection of appropriate cleaning and disinfecting products; educating staff to include environmental services, patient equipment, and nursing; monitoring compliance (eg, thoroughness of cleaning, product use) with feedback (ie, just in time coaching); and implementing a "no touch" room decontamination technology and to ensure compliance for patients on contact and enteric precautions. This article will also discuss new technologies (eg, continuous room decontamination technology) that may enhance our infection prevention strategies in the future.

Semi-automatic instrumentation for nucleic acid extraction and purification to quantify pathogens on surfaces

A semi-automated detection system compatible with PCR that can detect infectious pathogens on wide surfaces in a short time.

Wiping out MRSA: effect of introducing a universal disinfection wipe in a large UK teaching hospital

Background

Contamination of the inanimate environment around patients constitutes an important reservoir of MRSA. Here we describe the effect of introducing a universal disinfection wipe in all wards on the rates of MRSA acquisitions and bacteraemias across a large UK teaching hospital.

Methods

A segmented Poisson regression model was used to detect any significant changes in the monthly numbers per 100,000 bed days of MRSA acquisitions and bacteraemias from April 2013 - December 2017 across QEHB.

Results

From April 2013 to April 2016, cleaning of ward areas and multi-use patient equipment by nursing staff consisted of a two-wipe system. Firstly, a detergent wipe was used, which was followed by a disinfection step using an alcohol wipe. In May 2016, QEHB discontinued the use of a two-wipe system for cleaning and changed to a one wipe system utilising a combined cleaning and disinfection wipe containing a quaternary ammonium compound. The segmented Poisson regression model demonstrated that the rate of MRSA acquisition/100,000 patient bed days was affected by the introduction of the new wiping regime (20.7 to 9.4 per 100,000 patient bed days; p <0.005).

Discussion

Using a Poisson model we demonstrated that the average hospital acquisition rate of MRSA/100,000 patient bed days reduced by 6.3% per month after the introduction of the new universal wipe.

Conclusion

We suggest that using a simple one wipe system for nurse cleaning is an effective strategy to reduce the spread and incidence of healthcare associated MRSA.

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.

Time to abandon the hygiene hypothesis: new perspectives on allergic disease, the human microbiome, infectious disease prevention and the role of targeted hygiene

Aims:

To review the burden of allergic and infectious diseases and the evidence for a link to microbial exposure, the human microbiome and immune system, and to assess whether we could develop lifestyles which reconnect us with exposures which could reduce the risk of allergic disease while also protecting against infectious disease.

Methods:

Using methodology based on the Delphi technique, six experts in infectious and allergic disease were surveyed to allow for elicitation of group judgement and consensus view on issues pertinent to the aim.

Results:

Key themes emerged where evidence shows that interaction with microbes that inhabit the natural environment and human microbiome plays an essential role in immune regulation. Changes in lifestyle and environmental exposure, rapid urbanisation, altered diet and antibiotic use have had profound effects on the human microbiome, leading to failure of immunotolerance and increased risk of allergic disease. Although evidence supports the concept of immune regulation driven by microbe–host interactions, the term ‘hygiene hypothesis’ is a misleading misnomer. There is no good evidence that hygiene, as the public understands, is responsible for the clinically relevant changes to microbial exposures.

Conclusion:

Evidence suggests a combination of strategies, including natural childbirth, breast feeding, increased social exposure through sport, other outdoor activities, less time spent indoors, diet and appropriate antibiotic use, may help restore the microbiome and perhaps reduce risks of allergic disease. Preventive efforts must focus on early life. The term ‘hygiene hypothesis’ must be abandoned. Promotion of a risk assessment approach (targeted hygiene) provides a framework for maximising protection against pathogen exposure while allowing spread of essential microbes between family members. To build on these findings, we must change public, public health and professional perceptions about the microbiome and about hygiene. We need to restore public understanding of hygiene as a means to prevent infectious disease.

A unified framework for developing effective hygiene procedures for hands, environmental surfaces and laundry in healthcare, domestic, food handling and other settings

Hygiene procedures for hands, surfaces and fabrics are central to preventing spread of infection in settings including healthcare, food production, catering, agriculture, public settings, and home and everyday life. They are used in situations including hand hygiene, clinical procedures, decontamination of environmental surfaces, respiratory hygiene, food handling, laundry hygiene, toilet hygiene and so on. Although the principles are common to all, approaches currently used in different settings are inconsistent. A concern is the use of inconsistent terminology which is misleading, especially to people we need to communicate with such as the public or cleaning professionals. This paper reviews the data on current approaches, alongside new insights to developing hygiene procedures. Using this data, we propose a more scientifically-grounded framework for developing procedures that maximize protection against infection, based on consistent principles and terminology, and applicable across all settings. A key feature is use of test models which assess the state of surfaces after treatment rather than product performance alone. This allows procedures that rely on removal of microbes to be compared with those employing chemical or thermal inactivation. This makes it possible to ensure that a consistent "safety target level" is achieved regardless of the type of procedure used, and allows us deliver maximum health benefit whilst ensuring prudent usage of antimicrobial agents, detergents, water and energy.

Effectiveness of various cleaning and disinfectant products on Clostridium difficile spores of PCR ribotypes 010, 014 and 027

Background

In healthcare facilities, Clostridium difficile infections spread by transmission of bacterial spores. Appropriate sporicidal disinfectants are needed to prevent development of clusters and outbreaks. In this study different cleaning/disinfecting wipes and sprays were tested for their efficacy against spores of distinctive C. difficile PCR ribotypes.

Methods

Four different products were tested; 1) hydrogen peroxide 1.5%; 2) glucoprotamin 1.5%; 3) a mixture of ethanol, propane and N-alkyl amino propyl glycine; and 4) a mixture of didecyldimonium chloride, benzalkonium chloride, polyaminopropyl, biguanide and dimenthicone as active ingredients. Tiles were contaminated with a test solution containing a concentration of 5x10⁶CFU/ml spores of C. difficile strains belonging to PCR ribotypes 010, 014 or 027. The tiles were left to dry for an hour and then wiped or sprayed with one of the sprays or wipes as intended by the manufacturers. When products neutralized after 5 min, microbiological cultures and ATP measures were performed.

Results

Irrespective of the disinfection method, the microbial count log₁₀ reduction of C. difficile PCR ribotype 010 was highest, followed by the reduction of C. difficile 014 and C. difficile 027. Overall, the wipes performed better than the sprays with the same active ingredient. On average, although not significantly, a difference in relative light units (RLU) reduction between the wipes and sprays was found. The wipes had a higher RLU log₁₀ reduction, but no significant difference for RLU reduction was observed between the different C. difficile strains (p = 0.16).

Conclusion

C. difficile spores of PCR ribotypes 014 and 027 strains are more difficult to eradicate than non-toxigenic PCR ribotype 010. In general, impregnated cleaning/disinfection wipes performed better than ready-to-use sprays. Wipes with hydrogen peroxide (1.5%) showed the highest bactericidal activity.

Role of surface energy and nano-roughness in the removal efficiency of bacterial contamination by nonwoven wipes from frequently touched surfaces

Healthcare associated infections (HCAIs) are responsible for substantial patient morbidity, mortality and economic cost. Infection control strategies for reducing rates of transmission include the use of nonwoven wipes to remove pathogenic bacteria from frequently touched surfaces. Wiping is a dynamic process that involves physicochemical mechanisms to detach and transfer bacteria to fibre surfaces within the wipe. The purpose of this study was to determine the extent to which systematic changes in fibre surface energy and nano-roughness influence removal of bacteria from an abiotic polymer surface in dry wiping conditions, without liquid detergents or disinfectants. Nonwoven wipe substrates composed of two commonly used fibre types, lyocell (cellulosic) and polypropylene, with different surface energies and nano-roughnesses, were manufactured using pilot-scale nonwoven facilities to produce samples of comparable structure and dimensional properties. The surface energy and nano-roughness of some lyocell substrates were further adjusted by either oxygen (O2) or hexafluoroethane (C2F6) gas plasma treatment. Static adpression wiping of an inoculated surface under dry conditions produced removal efficiencies of between 9.4% and 15.7%, with no significant difference (p < 0.05) in the relative removal efficiencies of Escherichia coli, Staphylococcus aureus or Enterococcus faecalis. However, dynamic wiping markedly increased peak wiping efficiencies to over 50%, with a minimum increase in removal efficiency of 12.5% and a maximum increase in removal efficiency of 37.9% (all significant at p < 0.05) compared with static wiping, depending on fibre type and bacterium. In dry, dynamic wiping conditions, nonwoven wipe substrates with a surface energy closest to that of the contaminated surface produced the highest E. coli removal efficiency, while the associated increase in fibre nano-roughness abrogated this trend with S. aureus and E. faecalis.

Exploring surface cleaning strategies in hospital to prevent contact transmission of methicillin-resistant Staphylococcus aureus

Background

Cleaning of environmental surfaces in hospitals is important for the control of methicillin-resistant Staphylococcus aureus (MRSA) and other hospital-acquired infections transmitted by the contact route. Guidance regarding the best approaches for cleaning, however, is limited.

Methods

In this study, a mathematical model based on ordinary differential equations was constructed to study MRSA concentration dynamics on high-touch and low-touch surfaces, and on the hands and noses of two patients (in two hospitals rooms) and a health care worker in a hypothetical hospital environment. Two cleaning interventions – whole room cleaning and wipe cleaning of touched surfaces – were considered. The performance of the cleaning interventions was indicated by a reduction in MRSA on the nose of a susceptible patient, relative to no intervention.

Results

Whole room cleaning just before first patient care activities of the day was more effective than whole room cleaning at other times, but even with 100% efficiency, whole room cleaning only reduced the number of MRSA transmitted to the susceptible patient by 54%. Frequent wipe cleaning of touched surfaces was shown to be more effective that whole room cleaning because surfaces are rapidly re-contaminated with MRSA after cleaning. Wipe cleaning high-touch surfaces was more effective than wipe cleaning low-touch surfaces for the same frequency of cleaning. For low wipe cleaning frequency (≤3 times per hour), high-touch surfaces should be targeted, but for high wipe cleaning frequency (>3 times per hour), cleaning should target high- and low-touch surfaces in proportion to the surface touch frequency. This study reproduces the observations from a field study of room cleaning, which provides support for the validity of our findings.

Conclusions

Daily whole room cleaning, even with 100% cleaning efficiency, provides limited reduction in the number of MRSA transmitted to susceptible patients via the contact route; and should be supplemented with frequent targeted cleaning of high-touch surfaces, such as by a wipe or cloth containing disinfectant.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-2120-z) contains supplementary material, which is available to authorized users.

Do we have enough evidence how seasonal influenza is transmitted and can be prevented in hospitals to implement a comprehensive policy?

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Vaccinated HCW 4.81, unvaccinated 7.54 lab-proven influenza episodes/100 HCWs/ season.

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2 RCTs partly directly-observed HCW mask wearing, 4 not observed underpowered, no effect on influenza transmission.

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There are no RCTs of screening HCWs/patients for influenza before entering hospital to prevent transmission.

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H₂O₂ vapor systems effectively clean patient rooms/medical equipment of influenza

Purpose

To identify if there is enough evidence at low risk-of-bias to prevent influenza transmission by vaccinating health-care workers (HCWs), patients and visitors; screening for laboratory-proven influenza all entering hospitals; screening asymptomatic individuals; identifying influenza supershedders; hand-washing and mask-wearing by HCWs, patients and visitors; and cleaning hospital rooms and equipment.

Principal Results

Vaccination reduces influenza episodes of vaccinated (4.81/100 HCW) compared to unvaccinated (7.54/100) HCWs/influenza season. A Cochrane review found for inactivated vaccines the Number Needed to Vaccinate (NNV) = 71 (95%CI 64%, 80%) for adults 18–60 (same age as HCWs) to prevent laboratory-proven influenza. There are no RCTs of screening HCWs, patients, visitors and influenza supershedders to prevent transmission. None of four RCTs of HCWs mask-wearing (two directly observed, two not) showed an effect because they were underpowered either due to small size or low circulation of influenza. Hospital rooms and equipment can effectively be cleaned of influenza by many chemicals and hydrogen peroxide vapor machines but the cleaning cycle needs shortening to increase the likelihood of adoption.

Major Conclusions

HCW vaccination is a partial solution with current vaccination levels. There are no RCTs of screening HCWs, patients and visitors demonstrating preventing influenza transmission. Only one study costed furloughing HCWs with influenza and no RCTs have identified benefits of isolating influenza supershedders. RCTs of directly- and electronically continuously-observed mask-wearing and hand-hygiene and RCTs of incentives for meticulous hygiene are required. RCTs of engineering solutions (external venting, frequent room air changes) are needed. A wide range of chemicals effectively cleans hospital rooms and equipment from influenza. Hydrogen peroxide vapor is effective against influenza and a wide range of bacterial pathogens with patient room changes, and clean areas cleaners do not clean but its cleaning cycle needs shortening to increase the likelihood of adoption of cleaning rooms vacated by influenza patients.

Monitoring and improving the effectiveness of surface cleaning and disinfection

Disinfection of noncritical environmental surfaces and equipment is an essential component of an infection prevention program. Noncritical environmental surfaces and noncritical medical equipment surfaces may become contaminated with infectious agents and may contribute to cross-transmission by acquisition of transient hand carriage by health care personnel. Disinfection should render surfaces and equipment free of pathogens in sufficient numbers to prevent human disease (ie, hygienically clean).