Eradication of persistent environmental MRSA

Environmental hygiene strategies to combat antimicrobial resistance in healthcare settings

In this manuscript, we highlight current literature on environmental hygiene techniques to combat reservoirs of antibiotic resistant organisms in the healthcare environment. We discuss several topics for each strategy, including mechanism of action, assessment of effectiveness based on studies, cost, and real-world translatability. The techniques and topics summarized here are not inclusive of all available environmental hygiene techniques but highlight some of the more popular and investigated strategies. We focus on the following: Ultraviolet radiation, hydrogen peroxide vapor, copper-coated surfaces, phages, interventions involving sinks, and educational initiatives.

Use of Hydrogen Peroxide Vapour for Microbiological Disinfection in Hospital Environments: A Review

Disinfection of nosocomial pathogens in hospitals is crucial to combat healthcare-acquired infections, which can be acquired by patients, visitors and healthcare workers. However, the presence of a wide range of pathogens and biofilms, combined with the indiscriminate use of antibiotics, presents infection control teams in healthcare facilities with ongoing challenges in the selection of biocides and application methods. This necessitates the development of biocides and innovative disinfection methods that overcome the shortcomings of conventional methods. This comprehensive review finds the use of hydrogen peroxide vapour to be a superior alternative to conventional methods. Motivated by observations in previous studies, herein, we provide a comprehensive overview on the utilisation of hydrogen peroxide vapour as a superior high-level disinfection alternative in hospital settings. This review finds hydrogen peroxide vapour to be very close to an ideal disinfectant due to its proven efficacy against a wide range of microorganisms, safety to use, lack of toxicity concerns and good material compatibility. The superiority of hydrogen peroxide vapour was recently demonstrated in the case of decontamination of N95/FFP2 masks for reuse to address the critical shortage caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the COVID-19 pandemic. Despite the significant number of studies demonstrating antimicrobial activity, there remains a need to critically understand the mechanism of action by performing studies that simultaneously measure damage to all bacterial cell components and assess the correlation of this damage with a reduction in viable cell count. This can lead to improvement in antimicrobial efficacy and foster the development of superior approaches.

Inactivation of human coronaviruses using an automated room disinfection device

The emergence of more virulent and epidemic strains of viruses, especially in the context of COVID-19, makes it more important than ever to improve methods of decontamination. The objective of this study was to evaluate the potential of on-demand production of chlorine species to inactivate human coronaviruses. The commercial prototype disinfection unit was provided by Unipolar Water Technologies. The Unipolar device generates active chlorine species using an electrochemical reaction and dispenses the disinfectant vapour onto surfaces with an aspirator. The minimum effective concentration and exposure time of disinfectant were evaluated on human hepatoma (Huh7) cells using 50% tissue culture infectious dose (TCID50) assay and human coronavirus 229E (HCoV-229E), a surrogate for pathogenic human coronaviruses. We showed that chlorine species generated in the Unipolar device inactivate HCoV-229E on glass surfaces at ≥ 400 parts per million active chlorine concentration with a 5 min exposure time. Here, inactivation refers to the inability of the virus to infect the Huh7 cells. Importantly, no toxic effect was observed on Huh7 cells for any of the active chlorine concentrations and contact times tested.

The in situ efficacy of whole room disinfection devices: a literature review with practical recommendations for implementation

BACKGROUND

Terminal cleaning and disinfection of hospital patient rooms must be performed after discharge of a patient with a multidrug resistant micro-organism to eliminate pathogens from the environment. Terminal disinfection is often performed manually, which is prone to human errors and therefore poses an increased infection risk for the next patients. Automated whole room disinfection (WRD) replaces or adds on to the manual process of disinfection and can contribute to the quality of terminal disinfection. While the in vitro efficacy of WRD devices has been extensively investigated and reviewed, little is known about the in situ efficacy in a real-life hospital setting. In this review, we summarize available literature on the in situ efficacy of WRD devices in a hospital setting and compare findings to the in vitro efficacy of WRD devices. Moreover, we offer practical recommendations for the implementation of WRD devices.

METHODS

The in situ efficacy was summarized for four commonly used types of WRD devices: aerosolized hydrogen peroxide, H₂O₂ vapour, ultraviolet C and pulsed xenon ultraviolet. The in situ efficacy was based on environmental and clinical outcome measures. A systematic literature search was performed in PubMed in September 2021 to identify available literature. For each disinfection system, we summarized the available devices, practical information, in vitro efficacy and in situ efficacy.

RESULTS

In total, 54 articles were included. Articles reporting environmental outcomes of WRD devices had large variation in methodology, reported outcome measures, preparation of the patient room prior to environmental sampling, the location of sampling within the room and the moment of sampling. For the clinical outcome measures, all included articles reported the infection rate. Overall, these studies consistently showed that automated disinfection using any of the four types of WRD is effective in reducing environmental and clinical outcomes.

CONCLUSION

Despite the large variation in the included studies, the four automated WRD systems are effective in reducing the amount of pathogens present in a hospital environment, which was also in line with conclusions from in vitro studies. Therefore, the assessment of what WRD device would be most suitable in a specific healthcare setting mostly depends on practical considerations.

Service Robots in the Healthcare Sector

Traditionally, advances in robotic technology have been in the manufacturing industry due to the need for collaborative robots. However, this is not the case in the service sectors, especially in the healthcare sector. The lack of emphasis put on the healthcare sector has led to new opportunities in developing service robots that aid patients with illnesses, cognition challenges and disabilities. Furthermore, the COVID-19 pandemic has acted as a catalyst for the development of service robots in the healthcare sector in an attempt to overcome the difficulties and hardships caused by this virus. The use of service robots are advantageous as they not only prevent the spread of infection, and reduce human error but they also allow front-line staff to reduce direct contact, focusing their attention on higher priority tasks and creating separation from direct exposure to infection. This paper presents a review of various types of robotic technologies and their uses in the healthcare sector. The reviewed technologies are a collaboration between academia and the healthcare industry, demonstrating the research and testing needed in the creation of service robots before they can be deployed in real-world applications and use cases. We focus on how robots can provide benefits to patients, healthcare workers, customers, and organisations during the COVID-19 pandemic. Furthermore, we investigate the emerging focal issues of effective cleaning, logistics of patients and supplies, reduction of human errors, and remote monitoring of patients to increase system capacity, efficiency, resource equality in hospitals, and related healthcare environments.

Photolysis-driven indoor air chemistry following cleaning of hospital wards

Effective cleaning techniques are essential for the sterilization of rooms in hospitals and industry. No-touch devices (NTDs) that use fumigants such as hydrogen peroxide (H₂ O₂ ), formaldehyde (HCHO), ozone (O₃ ), and chlorine dioxide (OClO) are a recent innovation. This paper reports a previously unconsidered potential consequence of such cleaning technologies: the photochemical formation of high concentrations of hydroxyl radicals (OH), hydroperoxy radicals (HO₂ ), organic peroxy radicals (RO₂ ), and chlorine radicals (Cl) which can form harmful reaction products when exposed to chemicals commonly found in indoor air. This risk was evaluated by calculating radical production rates and concentrations based on measured indoor photon fluxes and typical fumigant concentrations during and after cleaning events. Sunlight and fluorescent tubes without covers initiated photolysis of all fumigants, and plastic-covered fluorescent tubes initiated photolysis of only some fumigants. Radical formation was often dominated by photolysis of fumigants during and after decontamination processes. Radical concentrations were predicted to be orders of magnitude greater than background levels during and immediately following cleaning events with each fumigant under one or more illumination condition. Maximum predicted radical concentrations (1.3 × 10⁷ molecule cm^-3 OH, 2.4 ppb HO₂ , 6.8 ppb RO₂ and 2.2 × 10⁸ molecule cm^-3 Cl) were much higher than baseline concentrations. Maximum OH concentrations occurred with O₃ photolysis, HO₂ with HCHO photolysis, and RO₂ and Cl with OClO photolysis. Elevated concentrations may persist for hours after NTD use, depending on the air change rate and air composition. Products from reactions involving radicals could significantly decrease air quality when disinfectants are used, leading to adverse health effects for occupants.

Environmental Disinfection of a Dental Clinic during the Covid-19 Pandemic: A Narrative Insight

BACKGROUND

The control of biological hazard risk in health care and dental clinic environments represents a critical point in relation to the Covid-19 infection outbreak and international public health emergency. The purpose of the present review was to evaluate the scientific literature on the no-touch disinfection procedures in dental clinics aiming to limit transmission via airborne particles or fomites using no-touch procedures for environmental decontamination of dental clinics.

METHODS

An electronic database literature search was performed to retrieve research papers about Covid-19 and no-touch disinfection topics including full-length articles, editorials, commentaries, and outbreak studies. A total of 86 papers were retrieved by the electronic research.

RESULTS

No clinical article about the decontamination of a dental clinic during the Covid-19 pandemic was detected. About the topic of hospital decontamination, we found different no-touch disinfection procedures used in hospital against highly resistant organisms, but no data were found in the search for such procedures with respect to SARS-CoV-2: (1) aerosolized hydrogen peroxide, (2) H2O2 vapor, (3) ultraviolet C light, (4) pulsed xenon, and (5) gaseous ozone. One paper was retrieved concerning SARS-CoV-2; 32 documents focused on SARS and MERS. The cleaning and disinfection protocol of health care and dental clinic environment surfaces are essential elements of infection prevention programs, especially during the SARS-CoV-2 pandemic.

CONCLUSION

The decontamination technique that best suits the needs of the dental clinic is peroxide and hypochlorous which can be sprayed via a device at high turbine speed with the ability of producing small aerosol particles, recommendable also for their low cost.

Role of Hydrogen Peroxide Vapor (HPV) for the Disinfection of Hospital Surfaces Contaminated by Multiresistant Bacteria

The emergence of multiresistant bacterial strains as agents of healthcare-related infection in hospitals has prompted a review of the control techniques, with an added emphasis on preventive measures, namely good clinical practices, antimicrobial stewardship, and appropriate environmental cleaning. The latter item is about the choice of an appropriate disinfectant as a critical role due to the difficulties often encountered in obtaining a complete eradication of environmental contaminations and reservoirs of pathogens. The present review is focused on the effectiveness of hydrogen peroxide vapor, among the new environmental disinfectants that have been adopted. The method is based on a critical review of the available literature on this topic.

An overview of automated room disinfection systems: When to use them and how to choose them

Conventional disinfection methods are limited by reliance on the operator to ensure appropriate selection, formulation, distribution, and contact time of the agent. Automated room disinfection (ARD) systems remove or reduce reliance on operators and so they have the potential to improve the efficacy of terminal disinfection. The most commonly used systems are hydrogen peroxide vapor (H₂O₂ vapor), aerosolized hydrogen peroxide (aHP), and ultraviolet (UV) light. These systems have important differences in their active agent, delivery mechanism, efficacy, process time, and ease of use. The choice of ARD system should be influenced by the intended application, the evidence base for effectiveness, practicalities of implementation, and cost considerations.

Staphylococcus aureus extracellular vesicles (EVs): surface-binding antagonists of biofilm formation

The prevalence of Staphylococcus aureus worldwide as a nosocomial infectious agent is recognized but the reason behind the spread of this bacterium has remained elusive. Here, we hypothesized that the communication of S. aureus might benefit from it blocking other bacteria from establishing themselves on the surface. This was found to be the case for several pathogens as the S. aureus supernatant curtailed their ability to form biofilms. Subsequent analyses using Acinetobacter baumannii as a model found this effect is primarily mediated by S. aureus' extracellular vesicles (EVs), which bound to the polystyrene surface. We found the EV-treated surfaces were significantly more hydrophilic after EV treatment, a condition that made it difficult for A. baumannii to initially adhere to the polystyrene surface and reduced its resulting biofilm by up to 93%. Subsequent tests found this also extended to several other bacterial pathogens, with a 40-70% decrease in their biofilm mass. The S. aureus EVs and their activity still remained after the surface was washed with 10% bleach, while the use of ethylenediaminetetraacetic acid (EDTA) removed both the EVs from the surface and their activity.

High-touch surfaces: microbial neighbours at hand

Despite considerable efforts, healthcare-associated infections (HAIs) continue to be globally responsible for serious morbidity, increased costs and prolonged length of stay. Among potentially preventable sources of microbial pathogens causing HAIs, patient care items and environmental surfaces frequently touched play an important role in the chain of transmission. Microorganisms contaminating such high-touch surfaces include Gram-positive and Gram-negative bacteria, viruses, yeasts and parasites, with improved cleaning and disinfection effectively decreasing the rate of HAIs. Manual and automated surface cleaning strategies used in the control of infectious outbreaks are discussed and current trends concerning the prevention of contamination by the use of antimicrobial surfaces are taken into consideration in this manuscript.

Fighting MRSA Infections in Hospital Care: How Organizational Factors Matter

OBJECTIVE

To identify factors associated with methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections at the level of the hospital organization.

DATA SOURCES

Data from all 173 acute trusts in the English National Health Service (NHS).

STUDY DESIGN

A longitudinal study based on trust-level panel data for the 5-year period from April 2004 to March 2009. Fixed effects negative binominal and system generalized method of moment models were used to examine the effect of (i) patient mix characteristics, (ii) resource endowments, and (iii) infection control practices on yearly MRSA counts.

DATA COLLECTION

Archival and staff survey data from multiple sources, including Public Health England, the English Department of Health, and the Healthcare Commission, were merged to form a balanced panel dataset.

PRINCIPAL FINDINGS

MRSA infections decrease with increases in general cleaning (-3.52 MRSA incidents per 1 standard deviation increase; 95 percent confidence interval: -6.61 to -0.44), infection control training (-3.29; -5.22 to -1.36), hand hygiene (-2.72; -4.76 to -0.68), and error reporting climate (-2.06; -4.09 to -0.04).

CONCLUSIONS

Intensified general cleaning, improved hand hygiene, additional infection control training, and a climate conducive to error reporting emerged as the factors most closely associated with trust-level reductions in MRSA infections over time.

Effectiveness of ultraviolet devices and hydrogen peroxide systems for terminal room decontamination: Focus on clinical trials

Over the last decade, substantial scientific evidence has accumulated that indicates contamination of environmental surfaces in hospital rooms plays an important role in the transmission of key health care-associated pathogens (eg, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Clostridium difficile, Acinetobacter spp). For example, a patient admitted to a room previously occupied by a patient colonized or infected with one of these pathogens has a higher risk for acquiring one of these pathogens than a patient admitted to a room whose previous occupant was not colonized or infected. This risk is not surprising because multiple studies have demonstrated that surfaces in hospital rooms are poorly cleaned during terminal cleaning. To reduce surface contamination after terminal cleaning, no touch methods of room disinfection have been developed. This article will review the no touch methods, ultraviolet light devices, and hydrogen peroxide systems, with a focus on clinical trials which have used patient colonization or infection as an outcome. Multiple studies have demonstrated that ultraviolet light devices and hydrogen peroxide systems have been shown to inactivate microbes experimentally plated on carrier materials and placed in hospital rooms and to decontaminate surfaces in hospital rooms naturally contaminated with multidrug-resistant pathogens. A growing number of clinical studies have demonstrated that ultraviolet devices and hydrogen peroxide systems when used for terminal disinfection can reduce colonization or health care-associated infections in patients admitted to these hospital rooms.

Modern technologies for improving cleaning and disinfection of environmental surfaces in hospitals

Experts agree that careful cleaning and disinfection of environmental surfaces are essential elements of effective infection prevention programs. However, traditional manual cleaning and disinfection practices in hospitals are often suboptimal. This is often due in part to a variety of personnel issues that many Environmental Services departments encounter. Failure to follow manufacturer’s recommendations for disinfectant use and lack of antimicrobial activity of some disinfectants against healthcare-associated pathogens may also affect the efficacy of disinfection practices.

Improved hydrogen peroxide-based liquid surface disinfectants and a combination product containing peracetic acid and hydrogen peroxide are effective alternatives to disinfectants currently in widespread use, and electrolyzed water (hypochlorous acid) and cold atmospheric pressure plasma show potential for use in hospitals. Creating “self-disinfecting” surfaces by coating medical equipment with metals such as copper or silver, or applying liquid compounds that have persistent antimicrobial activity surfaces are additional strategies that require further investigation.

Newer “no-touch” (automated) decontamination technologies include aerosol and vaporized hydrogen peroxide, mobile devices that emit continuous ultraviolet (UV-C) light, a pulsed-xenon UV light system, and use of high-intensity narrow-spectrum (405 nm) light. These “no-touch” technologies have been shown to reduce bacterial contamination of surfaces. A micro-condensation hydrogen peroxide system has been associated in multiple studies with reductions in healthcare-associated colonization or infection, while there is more limited evidence of infection reduction by the pulsed-xenon system. A recently completed prospective, randomized controlled trial of continuous UV-C light should help determine the extent to which this technology can reduce healthcare-associated colonization and infections.

In conclusion, continued efforts to improve traditional manual disinfection of surfaces are needed. In addition, Environmental Services departments should consider the use of newer disinfectants and no-touch decontamination technologies to improve disinfection of surfaces in healthcare.

Reduction in the incidence of hospital-acquired MRSA following the introduction of a chlorine dioxide 275 ppm based disinfecting agent in a district general hospital

Background

Methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile are major nosocomial pathogens whose control relies on effective antimicrobial stewardship and infection control practices. This study evaluates the impact of a chlorine dioxide-based disinfectant (275 ppm) on the incidence of hospital-acquired (HA) MRSA and HA-Clostridium difficile infection (CDI) in a district general hospital.

Methods

This study was carried out from November 2009 to September 2013. From November 2009 to October 2011 sodium dichloroisocyanurate was used for routine environmental disinfection. In November 2011, this was changed to a chlorine dioxide 275 ppm based disinfectant. This product was introduced into the hospital in a phased manner with intensive training on its use provided to all nursing, nursing auxiliary and hotel services staff. The effect of this change on the incidence of HA-MRSA and HA-CDI was assessed using segmented regression analysis of interrupted time series. In addition, the potential cost savings as a result of this intervention were assessed.

Results

The HA-MRSA trend from November 2009 to October 2011 significantly increased (p=0.006). Following the introduction of the chlorine dioxide-based disinfectant there was significant decrease in the HA-MRSA trend, with the monthly incidence being reduced by 0.003 cases/100 bed days (p=0.001), equating to an average of four cases per month after 12 months of use This resulted in an annual potential cost saving of £276 000. No significant effect on the incidence of HA-CDI was observed (coefficient -0.03; p=0.873).

Conclusion

This study highlights the importance of effective environmental inanimate surface decontamination in controlling the spread of MRSA and the potential cost savings that can be achieved through decreasing HA-MRSA rates.

Extremely high prevalence of antiseptic resistant Quaternary Ammonium Compound E gene among clinical isolates of multiple drug resistant Acinetobacter baumannii in Malaysia

Background

Antiseptics are commonly used for the management of MDR (multiple drug resistance) pathogens in hospitals. They play crucial roles in the infection control practices. Antiseptics are often used for skin antisepsis, gauze dressing, preparation of anatomical sites for surgical procedure, hand sterilization before in contact with an infected person, before an invasive procedure and as surgical scrub.

Methods

We screened 122 multiple drug resistant Acinetobacter baumannii (MDRAB) isolated from admitted patients in one of the tertiary care hospital in Malaysia for the presence of antiseptic resistant genes qacA and qacE (Quaternary Ammonium Compound) and susceptibility towards chlorhexidine (CLX), benzalkonium (BZK) and benzethonium (BZT).

Results

Eighty-nine (73%) isolates harboured qacE gene, while none were positive for qacA. The MIC ranged from 0.2 to 0.6 for CLX, 0.02 to 0.2 for BZK and 0.04 to 0.2 μg/mL for BZT. The highest number of qacE positive isolates were obtained from surgery (n = 24; 27%; p < 0.05), followed by medical ward (n = 23; 25.8%) and ICU (n = 21; 23.6%). Majority of the isolates from wound swabs (n = 33; 37%), T/aspirate (n = 16; 18%) and tissue (n = 10; 11.2%) harboured the qacE genes.

Conclusion

The present investigation showed high prevalence of qacE gene among the studied isolates. Antiseptics are important components of infection control, continuous monitoring of antiseptics use in the hospital is cautioned.

A Head-to-Head Comparison of Hydrogen Peroxide Vapor and Aerosol Room Decontamination Systems

Objective.

New technologies have emerged in recent years for the disinfection of hospital rooms and equipment that may not be disinfected adequately using conventional methods. There are several hydrogen peroxide–based area decontamination technologies on the market, but no head-to-head studies have been performed.

Design.

We conducted a head-to-head in vitro comparison of a hydrogen peroxide vapor (HPV) system (Bioquell) and an aerosolized hydrogen peroxide (aHP) system (Sterinis).

Setting.

The tests were conducted in a purpose-built 136-m3test room.

Methods.

One HPV generator and 2 aHP machines were used, following recommendations of the manufacturers. Three repeated tests were performed for each system. The microbiological efficacy of the 2 systems was tested using 6-log Tyvek-pouchedGeobacillus stearo-thermophilusbiological indicators (BIs). The indicators were placed at 20 locations in the first test and 14 locations in the subsequent 2 tests for each system.

Results.

All BIs were inactivated for the 3 HPV tests, compared with only 10% in the first aHP test and 79% in the other 2 aHP tests. The peak hydrogen peroxide concentration was 338 ppm for HPV and 160 ppm for aHP. The total cycle time (including aeration) was 3 and 3.5 hours for the 3 HPV tests and the 3 aHP tests, respectively. Monitoring around the perimeter of the enclosure with a handheld sensor during tests of both systems did not identify leakage.

Conclusion.

One HPV generator was more effective than 2 aHP machines for the inactivation ofG. stearothermophilusBIs, and cycle times were faster for the HPV system.

The Role Played by Contaminated Surfaces in the Transmission of Nosocomial Pathogens

Studies in the 1970s and 1980s suggested that environmental surface contamination played a negligible role in the endemic transmission of healthcare-associated infections. However, recent studies have demonstrated that several major nosocomial pathogens are shed by patients and contaminate hospital surfaces at concentrations sufficient for transmission, survive for extended periods, persist despite attempts to disinfect or remove them, and can be transferred to the hands of healthcare workers. Evidence is accumulating that contaminated surfaces make an important contribution to the epidemic and endemic transmission ofClostridium difficile,vancomycin-resistant enterococci, methicillin-resistantStaphylococcus aureus, Acinetobacter baumannii, Pseudomonas aeruginosa,and norovirus and that improved environmental decontamination contributes to the control of outbreaks. Efforts to improve environmental hygiene should include enhancing the efficacy of cleaning and disinfection and reducing the shedding of pathogens. Further high-quality studies are needed to clarify the role played by surfaces in nosocomial transmission and to determine the effectiveness of different interventions in reducing associated infection rates.

Design Research and the Globalization of Healthcare Environments

OBJECTIVE:

Global healthcare practice has expanded in the past 20 years. At the same time the incorporation of research into the design process has gained prominence as a best practice among architects. The authors of this study investigated the status of design research in a variety of international settings. We intended to answer the question, “how pervasive is healthcare design research outside of the United States?”

METHOD:

The authors reviewed the international literature on the design of healthcare facilities. More than 500 international studies and conference proceedings were incorporated in this literature review. A team of five research assistants searched multiple databases comparing approximately 16 keywords to geographic location. Some of those keywords included: evidence-based design, salutogenic design, design research, and healthcare environment. Additional articles were gathered by contacting prominent researchers and asking for their personal assessment of local health design research studies.

RESULTS:

While there are design researchers in most parts of the world, the majority of studies focus on the needs of populations in developed countries and generate guidelines that have significant cost and cultural implications that prohibit their implementation in developing countries. Additionally, the body of literature discussing the role of culture in healthcare environments is extremely limited.

CONCLUSION:

Design researchers must address the cultural implications of their studies. Additionally, we need to expand our research objectives to address healthcare design in countries that have not been previous considered.

Identification and control of a gentamicin resistant, meticillin susceptible Staphylococcus aureus outbreak on a neonatal unit

We describe the identification and control of an outbreak of gentamicin resistant, meticillin susceptible Staphylococcus aureus (GR-MSSA) on a 36-bed neonatal unit (NNU) in London. Control measures included admission and weekly screening for GR-MSSA, cohorting affected babies, environmental and staff screening, hydrogen peroxide vapour (HPV) for terminal disinfection of cohort rooms, and reinforcement of hand hygiene. Seventeen babies were affected by the outbreak strain over ten months; seven were infected and ten were asymptomatic carriers. The outbreak strain was gentamicin resistant and all isolates were indistinguishable by pulsed-field gel electrophoresis. The outbreak strains spread rapidly and were associated with a high rate of bacteraemia (35% of 17 affected patients had bacteraemia vs. 10% of 284 patients with MSSA prior to the outbreak, p=0.007). None of 113 staff members tested were colonised with GR-MSSA. GR-MSSA was recovered from 11.5% of 87 environmental surfaces in cohort rooms, 7.1% of 28 communal surfaces and 4.1% of 74 surfaces after conventional terminal disinfection. None of 64 surfaces sampled after HPV decontamination yielded GR-MSSA. Recovery of GR-MSSA from two high level sites suggested that the organism could have been transmitted via air. Occasional breakdown in hand hygiene compliance and contaminated environmental surfaces probably contributed to transmission.

A guide to no-touch automated room disinfection (NTD) systems

Conventional disinfection methods are limited by reliance on the operator to ensure appropriate selection, formulation, distribution and contact time of the agent. ‘No-touch’ automated room disinfection (NTD) systems remove or reduce reliance on operators and so they have the potential to improve the efficacy of terminal disinfection. The most commonly used systems are hydrogen peroxide vapour (H₂O₂ vapour), aerosolised hydrogen peroxide (aHP) and ultraviolet (UV) radiation. These systems have important differences in their active agent, delivery mechanism, efficacy, process time and ease of use. The choice of NTD system should be influenced by the intended application, the evidence base for effectiveness, practicalities of implementation and cost constraints.

Disinfectants used for environmental disinfection and new room decontamination technology

Environmental contamination plays an important role in the transmission of several key health care-associated pathogens. Effective and thorough cleaning/disinfecting of the patient environment is essential. Room decontamination units (such as ultraviolet-C and hydrogen peroxide systems) aid in reducing environmental contamination after terminal room cleaning and disinfection.

Modern trends in infection control practices in intensive care units

Hospital-acquired infections (HAIs) are common in intensive care unit (ICU) patients and are associated with increased morbidity and mortality. There has been an increasing effort to prevent HAIs, and infection control practices are paramount in avoiding these complications. In the last several years, numerous developments have been seen in the infection prevention strategies in various health care settings. This article reviews the modern trends in infection control practices to prevent HAIs in ICUs with a focus on methods for monitoring hand hygiene, updates in isolation precautions, new methods for environmental cleaning, antimicrobial bathing, prevention of ventilator-associated pneumonia, central line-associated bloodstream infections, catheter-associated urinary tract infections, and Clostridium difficile infection.

Presence, distribution, and molecular epidemiology of methicillin-resistant Staphylococcus aureus in a small animal teaching hospital: a year-long active surveillance targeting dogs and their environment

Methicillin-resistant Staphylococcus aureus (MRSA) is known to be present in small animal veterinary clinical environments. However, a better understanding of the ecology and dynamics of MRSA in these environments is necessary for the development of effective infectious disease prevention and control programs. To achieve this goal, a yearlong active MRSA surveillance program was established at The Ohio State University (OSU) Veterinary Medical Center to describe the spatial and molecular epidemiology of this bacterium in the small animal hospital. Antimicrobial susceptibility testing, staphylococcal chromosomal cassette mec (SCCmec) typing, pulsed-field gel electrophoresis (PFGE) typing, and dendrogram analysis were used to characterize and analyze the 81 environmental and 37 canine-origin MRSA isolates obtained during monthly sampling events. Overall, 13.5% of surfaces were contaminated with MRSA at 1 or more sampling times throughout the year. The majority of the environmental and canine isolates were SCCmec type II (93.8% and 86.5%, respectively) and USA100 (90.1% and 86.5%, respectively). By PFGE analysis, these isolates were found to be closely related, which reflects a low diversity of MRSA strains circulating in the hospital. For 5 consecutive months, 1 unique pulsotype was the most prevalent across the medical services and was recovered from a variety of surfaces and hospital locations. Carts/gurneys, doors, and examination tables/floors were the most frequently contaminated surfaces. Some surfaces maintained the same pulsotypes for 3 consecutive months. Molecular analysis found that incoming MRSA-positive dogs were capable of introducing a new pulsotype into the hospital environment during the surveillance period. Our results suggest that once a MRSA strain is introduced into the hospital environment, it can be maintained and spread for extended periods of time. These findings can aid in the development of biosecurity and biocontainment protocols aimed at reducing environmental contamination and potential exposures to MRSA in veterinary hospital staff, clients, and patients.

The role of 'no-touch' automated room disinfection systems in infection prevention and control

BACKGROUND

Surface contamination in hospitals is involved in the transmission of pathogens in a proportion of healthcare-associated infections. Admission to a room previously occupied by a patient colonized or infected with certain nosocomial pathogens increases the risk of acquisition by subsequent occupants; thus, there is a need to improve terminal disinfection of these patient rooms. Conventional disinfection methods may be limited by reliance on the operator to ensure appropriate selection, formulation, distribution and contact time of the agent. These problems can be reduced by the use of 'no-touch' automated room disinfection (NTD) systems.

AIM

To summarize published data related to NTD systems.

METHODS

Pubmed searches for relevant articles.

FINDINGS

A number of NTD systems have emerged, which remove or reduce reliance on the operator to ensure distribution, contact time and process repeatability, and aim to improve the level of disinfection and thus mitigate the increased risk from the prior room occupant. Available NTD systems include hydrogen peroxide (H(2)O(2)) vapour systems, aerosolized hydrogen peroxide (aHP) and ultraviolet radiation. These systems have important differences in their active agent, delivery mechanism, efficacy, process time and ease of use. Typically, there is a trade-off between time and effectiveness among NTD systems. The choice of NTD system should be influenced by the intended application, the evidence base for effectiveness, practicalities of implementation and cost constraints.

CONCLUSION

NTD systems are gaining acceptance as a useful tool for infection prevention and control.

Reducing the spread of Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus on a burns unit through the intervention of an infection control bundle

Methicillin-resistant Staphylococcus aureus (MRSA) and Acinetobacter baumannii are major nosocomial pathogens in burns units. We investigated the impact of an infection control bundle on the incidence of nosocomial MRSA and A. baumannii in our burns unit, comparing a pre-intervention period (December 2006-August 2008) with an intervention period (September 2008-December 2009). The bundle comprised regular hydrogen peroxide vapour (HPV) disinfection of the rooms following discharge of patients colonized or infected by multidrug-resistant bacteria, pre-emptive cohort isolation of newly admitted patients before being proven culture negative, cohorting of colonized or infected patients, installation of two air disinfection systems in the corridors of the unit and improvement of material storage. We also investigated the microbiological efficacy of HPV disinfection by sampling the environment before and after HPV treatments. HPV disinfection eliminated pathogens from the environment and significantly reduced total bacterial surface counts, and total fungal air and surface counts, on both a unit and room scale. The incidence of nosocomial MRSA infection or colonization fell by 89.3% from 7.22 to 0.77 cases/1000 patient days (p<0.0001) and A. baumannii fell by 88.8% from 6.92 to 0.77 cases/1000 patient days (p=0.002) in the intervention period with no further outbreaks of these organisms occurring in this period. The infection control bundle resulted in a significant reduction in the incidence of nosocomial MRSA and A. baumannii in our burns unit and prevented further outbreaks of these organisms.

Patient-centered hand hygiene: the next step in infection prevention

Hand hygiene has been recognized as the most important means of preventing the transmission of infection, and great emphasis has been placed on ways to improve hand hygiene compliance by health care workers (HCWs). Despite increasing evidence that patients' flora and the hospital environment are the primary source of many infections, little effort has been directed toward involving patients in their own hand hygiene. Most previous work involving patients has included patients as monitors or auditors of hand hygiene practices by their HCWs. This article reviews the evidence on the benefits of including patients more directly in hand hygiene initiatives, and uses the framework of patient-centered safety initiatives to provide recommendations for the timing and implementation of patient hand hygiene protocols. It also addresses key areas for further research, practice guideline development, and implications for training of HCWs.

Comparison of the microbiological efficacy of hydrogen peroxide vapor and ultraviolet light processes for room decontamination

OBJECTIVE

To compare the microbiological efficacy of hydrogen peroxide vapor (HPV) and ultraviolet radiation (UVC) for room decontamination.

DESIGN

Prospective observational study.

SETTING

500-bed teaching hospital.

METHODS

HPV and UVC processes were performed in 15 patient rooms. Five high-touch sites were sampled before and after the processes and aerobic colony counts (ACCs) were determined. Carrier disks with ∼10(6) Clostridium difficile (CD) spores and biological indicators (BIs) with 10(4) and 10(6) Geobacillus stearothermophilus spores were placed in 5 sites before decontamination. After decontamination, CD log reductions were determined and BIs were recorded as growth or no growth.

RESULTS

93% of ACC samples that had growth before HPV did not have growth after HPV, whereas 52% of sites that had growth before UVC did not have growth after UVC (P < .0001). The mean CD log reduction was >6 for HPV and ∼2 for UVC. After HPV 100% of the 10(4) BIs did not grow, and 22% did not grow after UVC, with a range of 7%-53% for the 5 sites. For the 10(6) BIs, 99% did not grow after HPV and 0% did not grow after UVC. Sites out of direct line of sight were significantly more likely to show growth after UVC than after HPV. Mean cycle time was 153 (range, 140-177) min for HPV and 73 (range, 39-100) min for UVC (P < .0001).

CONCLUSION

Both HPV and UVC reduce bacterial contamination, including spores, in patient rooms, but HPV is significantly more effective. UVC is significantly less effective for sites that are out of direct line of sight.

Efficacy, efficiency and safety aspects of hydrogen peroxide vapour and aerosolized hydrogen peroxide room disinfection systems

BACKGROUND

This was a head-to-head comparison of two hydrogen-peroxide-based room decontamination systems.

AIM

To compare the efficacy, efficiency and safety of hydrogen peroxide vapour (HPV; Clarus R, Bioquell, Andover, U.K.) and aerosolized hydrogen peroxide (aHP; SR2, Sterinis, now supplied as Glosair, Advanced Sterilization Products (ASP), Johnson & Johnson Medical Ltd, Wokingham, U.K.) room disinfection systems.

METHOD

Efficacy was tested using 4- and 6-log Geobacillus stearothermophilus biological indicators (BIs) and in-house prepared test discs containing approximately 10(6) meticillin-resistant Staphylococcus aureus (MRSA), Clostridium difficile and Acinetobacter baumannii. Safety was assessed by detecting leakage of hydrogen peroxide using a hand-held detector. Efficiency was assessed by measuring the level of hydrogen peroxide using a hand-held sensor at three locations inside the room, 2 h after the start of the cycles.

FINDINGS

HPV generally achieved a 6-log reduction, whereas aHP generally achieved less than a 4-log reduction on the BIs and in-house prepared test discs. Uneven distribution was evident for the aHP system but not the HPV system. Hydrogen peroxide leakage during aHP cycles with the door unsealed, as per the manufacturer's operating manual, exceeded the short-term exposure limit (2 ppm) for more than 2 h. When the door was sealed with tape, as per the HPV system, hydrogen peroxide leakage was <1 ppm for both systems. The mean concentration of hydrogen peroxide in the room 2 h after the cycle started was 1.3 [standard deviation (SD) 0.4] ppm and 2.8 (SD 0.8) ppm for the four HPV and aHP cycles, respectively. None of the readings were <2 ppm for the aHP cycles.

CONCLUSION

The HPV system was safer, faster and more effective for biological inactivation.

Prevalence and characteristics of Staphylococcus aureus colonization among healthcare professionals in an urban teaching hospital

OBJECTIVE

To determine the prevalence of asymptomatic carriage of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) among healthcare professionals (HCPs) who experience varying degrees of exposure to ambulatory patients and to genetically characterize isolates.

METHODS

This single-center, cross-sectional study enrolled 256 staff from the intensive care units, emergency department, and prehospital services of an urban tertiary care university hospital in 2008. Occupational histories and nasal samples for S. aureus cultures were obtained. S. aureus isolates were genetically characterized with the use of spa typing and screened for mecA. MRSA isolates underwent further characterization.

RESULTS

S. aureus was isolated from 112 of 256 (43.8%) HCPs, including 30 of 52 (57.7%) paramedics, 51 of 124 (41.1%) nurses, 11 of 28 (39.3%) clerical workers, and 20 of 52 (38.5%) physicians. MRSA was isolated from 17 (6.6%) HCPs, including 1 (1.9%) paramedic, 13 (10.5%) nurses, 1 (3.6%) clerical worker, and 2 (3.8%) physicians. Among S. aureus isolates, 15.2% were MRSA. MRSA prevalence was 9.6% (12/125) in emergency department workers, 5.1% (4/79) in intensive care unit workers, and 1.9% (1/52) in emergency medical services workers. Compared with paramedics, who had the lowest prevalence of methicillin resistance among S. aureus isolates (1 of 30 [3.3%] isolates), nurses, who had the highest prevalence (13 of 51 [25.4%] isolates), had an odds ratio of 9.92 (95% confidence interval, 1.32-435.86; P = .02) for methicillin resistance. Analysis of 15 MRSA isolates revealed 7 USA100 strains, 6 USA300 strains, 1 USA800 strain, and 1 EMRSA-15 strain. All USA300 strains were isolated from emergency department personnel.

CONCLUSIONS

The observed prevalence of S. aureus and MRSA colonization among HCPs exceeds previously reported prevalences in the general population. The proportion of community-associated MRSA among all MRSA in this colonized HCP cohort reflects the distribution of the USA300 community-associated strain observed increasingly among US hospitalized patients.

Feasibility of routinely using hydrogen peroxide vapor to decontaminate rooms in a busy United States hospital

During a 22-month period at a 500-bed teaching hospital, 1,565 rooms that had housed patients infected with multidrug-resistant pathogens were decontaminated using hydrogen peroxide vapor. Hydrogen peroxide vapor decontamination required a mean time of 2 hours and 20 minutes, compared with 32 minutes for conventional cleaning. Despite the greater time required for decontamination, hydrogen peroxide vapor decontamination of selected patient rooms is feasible in a busy hospital with a mean occupancy rate of 94%.

Activity of a dry mist hydrogen peroxide system against environmental Clostridium difficile contamination in elderly care wards

Clostridium difficile causes serious healthcare-associated infections. Infection control is difficult, due in part to environmental contamination with C. difficile spores. These spores are relatively resistant to cleaning and disinfection. The activity of a dry mist hydrogen peroxide decontamination system (Sterinis) against environmental C. difficile contamination was assessed in three elderly care wards. Initial sampling for C. difficile was performed in 16 rooms across a variety of wards and specialties, using Brazier's CCEY (cycloserine-cefoxitin-egg yolk) agar. Ten rooms for elderly patients (eight isolation and two sluice rooms) were then resampled following dry mist hydrogen peroxide decontamination. Representative isolates of C. difficile were typed by polymerase chain reaction ribotyping. C. difficile was recovered from 3%, 11% and 26% of samples from low, medium and high risk rooms, respectively. In 10 high risk elderly care rooms, 24% (48/203) of samples were positive for C. difficile, with a mean of 6.8 colony-forming units (cfu) per 10 samples prior to hydrogen peroxide decontamination. Ribotyping identified the presence of the three main UK epidemic strains (ribotypes 001, 027 and 106) and four rooms contained mixed strains. After a single cycle of hydrogen peroxide decontamination, only 3% (7/203) of samples were positive (P<0.001), with a mean of 0.4 cfu per 10 samples ( approximately 94% reduction). The Sterinis hydrogen peroxide system significantly reduced the extent of environmental contamination with C. difficile in these elderly care rooms. This relatively quick and user-friendly technology might be a more reliable method of terminally disinfecting isolation rooms, following detergent cleaning, compared to the manual application of other disinfectants.

A Review of the Research Literature on Evidence-Based Healthcare Design

Objective:

This report surveys and evaluates the scientific research on evidence-based healthcare design and extracts its implications for designing better and safer hospitals.

Background:

It builds on a literature review conducted by researchers in 2004.

Methods:

Research teams conducted a new and more exhaustive search for rigorous empirical studies that link the design of hospital physical environments with healthcare outcomes. The review followed a two-step process, including an extensive search for existing literature and a screening of each identified study for the relevance and quality of evidence.

Results:

This review found a growing body of rigorous studies to guide healthcare design, especially with respect to reducing the frequency of hospital-acquired infections. Results are organized according to three general types of outcomes: patient safety, other patient outcomes, and staff outcomes. The findings further support the importance of improving outcomes for a range of design characteristics or interventions, including single-bed rooms rather than multibed rooms, effective ventilation systems, a good acoustic environment, nature distractions and daylight, appropriate lighting, better ergonomic design, acuity-adaptable rooms, and improved floor layouts and work settings. Directions for future research are also identified.

Conclusions:

The state of knowledge of evidence-based healthcare design has grown rapidly in recent years. The evidence indicates that well-designed physical settings play an important role in making hospitals safer and more healing for patients, and better places for staff to work.

MRSA and the environment: implications for comprehensive control measures

Environmental contamination with methicillin-resistant Staphylococcus aureus (MRSA) is established soon after colonized or infected patients become resident. There are many studies that detail the mechanisms of spread and environmental survival of methicillin-susceptible Staphylococcus aureus (MSSA); this knowledge translates directly into the same findings for MRSA. The potential ubiquity of MRSA in a health-care setting poses challenges for decontamination. Whereas patients and medical staff are important sources for MRSA spread, the environmental burden may contribute significantly in various contexts. Effective control measures must therefore include consideration for MRSA in the environment.

Assessing the biological efficacy and rate of recontamination following hydrogen peroxide vapour decontamination

The inanimate hospital environment can become contaminated with nosocomial pathogens. Hydrogen peroxide vapour (HPV) decontamination has proven effective for the eradication of persistent environmental contamination. We investigated the extent of meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE) and gentamicin-resistant Gram-negative rod (GNR) contamination in a ward side-room occupied by a patient with a history of MRSA, VRE and GNR infection and colonisation and investigated the impact of HPV decontamination. Fifteen standardised sites in the room were sampled using a selective broth enrichment protocol to culture MRSA, VRE and GNR. Sampling was performed before cleaning, after cleaning, after HPV decontamination and at intervals over the subsequent 19 days on two separate occasions. Environmental contamination was identified before cleaning on 60, 30 and 6.7% of sites for MRSA, GNR and VRE, respectively, and 40, 10 and 6.7% of sites after cleaning. Only one site (3.3%) was contaminated with MRSA after HPV decontamination. No recontamination with VRE was identified and no recontamination with MRSA and GNR was identified during the two days following HPV decontamination. Substantial recontamination was identified approximately one week after HPV decontamination towards post-cleaning levels for GNR and towards pre-cleaning levels for MRSA. HPV is more effective than standard terminal cleaning for the eradication of nosocomial pathogens. Recontamination was not immediate for MRSA and GNR but contamination returned within a week in a room occupied by a patient colonised with MRSA and GNR. This finding has important implications for the optimal deployment of HPV decontamination in hospitals.

Rapid recontamination with MRSA of the environment of an intensive care unit after decontamination with hydrogen peroxide vapour

Meticillin-resistant Staphylococcus aureus (MRSA) persists in the hospital environment and conventional cleaning procedures do not necessarily eliminate contamination. A prospective study was conducted on an intensive care unit to establish the level of environmental contamination with MRSA, assess the effectiveness of hydrogen peroxide vapour (HPV) decontamination and determine the rate of environmental recontamination. MRSA was isolated from 11.2% of environmental sites in the three months preceding the use of HPV and epidemiological typing revealed that the types circulating within the environment were similar to those colonising patients. After patient discharge and terminal cleaning using conventional methods, MRSA was isolated from five sites (17.2%). After HPV decontamination but before the readmission of patients, MRSA was not isolated from the environment. Twenty-four hours after readmitting patients, including two colonized with MRSA, the organism was isolated from five sites. The strains were indistinguishable from a strain with which a patient was colonized but were not all confined to the immediate vicinity of the colonized patient. In the eight weeks after the use of HPV, the environment was sampled on a weekly basis and MRSA was isolated from 16.3% sites. Hydrogen peroxide vapour is effective in eliminating bacteria from the environment but the rapid rate of recontamination suggests that it is not an effective means of maintaining low levels of environmental contamination in an open-plan intensive care unit.

Use of hydrogen peroxide vapor for deactivation of Mycobacterium tuberculosis in a biological safety cabinet and a room

Mycobacterium tuberculosis is an important human pathogen that is routinely cultured in clinical and research laboratories. M. tuberculosis can contaminate surfaces and is highly resistant to disinfection. We investigated whether hydrogen peroxide vapor (HPV) is effective for the deactivation of M. tuberculosis on experimentally contaminated surfaces in a biological safety cabinet (BSC) and a room. Biological indicators (BIs) consisting of an approximately 3-log(10) inoculum of M. tuberculosis on stainless steel discs and a 6-log(10) inoculum of Geobacillus stearothermophilus were exposed to HPV in BSC time course experiments and at 10 locations during room experiments. In three separate BSC experiments, M. tuberculosis BIs were transferred to growth media at 15-min intervals during a 180-min HPV exposure period. No M. tuberculosis BIs grew following 30 min of HPV exposure. In three separate room experiments, M. tuberculosis and G. stearothermophilus BIs were exposed to HPV for 90, 120, and 150 min, respectively. BIs for both microorganisms were deactivated in all 10 locations following 90 min of HPV exposure. HPV provides an alternative to traditional decontamination methods, such as formaldehyde fumigation, for laboratories and other areas contaminated with M. tuberculosis.