The environment and healthcare-acquired infections: why accurate reporting and evaluation of biological plausibility are important

Hospital cleaning: past, present, and future

INTRODUCTION

The importance of hospital cleaning for controlling healthcare-associated infection (HAI) has taken years to acknowledge. This is mainly because the removal of dirt is inextricably entwined with gender and social status, along with lack of evidence and confusion over HAI definitions. Reducing so-called endogenous infection due to human carriage entails patient screening, decolonisation and/or prophylaxis, whereas adequate ventilation, plumbing and cleaning are needed to reduce exogenous infection. These infection types remain difficult to separate and quantitate. Patients themselves demonstrate wide-ranging vulnerability to infection, which further complicates attempted ranking of control interventions, including cleaning. There has been disproportionate attention towards endogenous infection with less interest in managing environmental reservoirs.

QUANTIFYING CLEANING AND CLEANLINESS

Finding evidence for cleaning is compromised by the fact that modelling HAI rates against arbitrary measurements of cleaning/cleanliness requires universal standards and these are not yet established. Furthermore, the distinction between cleaning (soil removal) and cleanliness (soil remaining) is usually overlooked. Tangible bench marking for both cleaning methods and all surface types within different units, with modification according to patient status, would be invaluable for domestic planning, monitoring and specification.

AIMS AND OBJECTIVES

This narrative review will focus on recent history and current status of cleaning in hospitals. While its importance is now generally accepted, cleaning practices still need attention in order to determine how, when and where to clean. Renewed interest in removal and monitoring of surface bioburden would help to embed risk-based practice in hospitals across the world.

Antimicrobial efficacy and durability of copper formulations over one year of hospital use

OBJECTIVE

To evaluate 3 formulations of copper (Cu)-based self-sanitizing surfaces for antimicrobial efficacy and durability over 1 year in inpatient clinical areas and laboratories.

DESIGN

Randomized control trial.

SETTING

We assessed 3 copper formulations: (1) solid alloy 80% Cu-20% Ni (integral copper), (2) spray-on 80% Cu-20% Ni (spray-on) and (3) 16% composite copper-impregnated surface (CIS). In total, 480 coupons (1 cm2) of the 3 products and control surgical grade (AISI 316) stainless steel were inserted into gaskets and affixed to clinical carts used in patient care areas (including emergency and maternity units) and on microbiology laboratory bench work spaces (n = 240). The microbial burden and assessment of resistance to wear, corrosion, and material compatibility were determined every 3 months. Participants included 3 tertiary-care Canadian adult hospital and 1 pediatric-maternity hospital.

RESULTS

Copper formulations used on inpatient units statistically significantly reduced bacterial bioburden compared to stainless steel at months 3 and 6. Only the integral copper product had significantly less bacteria than stainless steel at month 12. No statistically significant differences were detected in microbial burden between copper formulations and stainless-steel coupons on microbiology laboratory benches where bacterial counts were low overall. All mass changes and corrosion rates of the formulations were acceptable by engineering standards.

CONCLUSIONS

Copper surfaces vary in their antimicrobial efficacy after 1 year of hospital use. Frequency of cleaning and disinfection influence the impact of copper; the greatest reduction in microbial bioburden occurred in clinical areas compared to the microbiology laboratory where cleaning and disinfection were performed multiple times daily.

Brass Alloys: Copper-Bottomed Solutions against Hospital-Acquired Infections?

Copper has been used for its antimicrobial properties since Antiquity. Nowadays, touch surfaces made of copper-based alloys such as brasses are used in healthcare settings in an attempt to reduce the bioburden and limit environmental transmission of nosocomial pathogens. After a brief history of brass uses, the various mechanisms that are thought to be at the basis of brass antimicrobial action will be described. Evidence shows that direct contact with the surface as well as cupric and cuprous ions arising from brass surfaces are instrumental in the antimicrobial effectiveness. These copper ions can lead to oxidative stress, membrane alterations, protein malfunctions, and/or DNA damages. Laboratory studies back up a broad spectrum of activity of brass surfaces on bacteria with the possible exception of bacteria in their sporulated form. Various parameters influencing the antimicrobial activity such as relative humidity, temperature, wet/dry inoculation or wear have been identified, making it mandatory to standardize antibacterial testing. Field trials using brass and copper surfaces consistently report reductions in the bacterial bioburden but, evidence is still sparse as to a significant impact on hospital acquired infections. Further work is also needed to assess the long-term effects of chemical/physical wear on their antimicrobial effectiveness.

Conflicts of interest in infection prevention and control research: no smoke without fire. A narrative review

Conflicts of interest (COIs) do occur in healthcare research, yet their impact on research in the field of infection prevention and control (IPC) is unknown. We conducted a narrative review aiming to identify examples of COIs in IPC research. In addition to well-known instances, we conducted PubMed and Google searches to identify and report case studies of COIs in IPC and antimicrobial resistance (AMR), which were chosen arbitrarily following consensus meetings, to illustrate different types of COIs. We also searched the Retraction Watch database and blog to systematically identify retracted IPC and/or infectious disease-related papers. Our review highlights COIs in academic research linked to ties between industry and physicians, journal editors, peer-reviewed journals' choice for publication, and guideline committees participants and authors. It explores how COIs can affect research and could be managed. We also present several selected case studies that involve (1) the chlorhexidine industry and how it has used marketing trials and key opinion leaders to promote off-label use of its products; (2) the copper industry and how reporting of its trials in IPC have furthered their agenda; (3) the influence of a company developing "closed infusion systems" for catheters and how this affects networks in low- and middle-income countries and guideline development; (4) potential perverse incentives hospitals may have in reporting healthcare-associated infection or AMR rates and how government intervention may restrict AMR research for fear of bad publicity and subsequent negative economic consequences. Finally, the analysis of reasons for the retraction of previously published papers highlights the fact that misconduct in research may have other motivations than financial gain, the most visible form of COIs. COIs occur in the field of research in general, and IPC and AMR are no exceptions. Their effects pervade all aspects of the research and publication processes. We believe that, in addition to improvements in management strategies of COIs, increased public funding should be available to decrease researchers' dependency on industry ties. Further research is needed on COIs and their management.

New insights on antimicrobial efficacy of copper surfaces in the healthcare environment: a systematic review

OBJECTIVES

Hospital-acquired infections (HAIs) are a major public health issue. The potential of antimicrobial copper surfaces in reducing HAIs' rates is of interest but remains unclear. We conducted a systematic review of studies assessing the activity of copper surfaces (colony-forming unit (CFU)/surface, both in vitro and in situ) as well as clinical studies. In vitro study protocols were analysed through a tailored checklist developed specifically for this review, in situ studies and non-randomized clinical studies were assessed using the ORION (Outbreak Reports and Intervention studies Of Nosocomial infection) checklist and randomized clinical studies using the CONSORT guidelines.

METHODS

The search was conducted using PubMed database with the keywords 'copper' and 'surfaces' and 'healthcare associated infections' or 'antimicrobial'. References from relevant articles, including reviews, were assessed and added when appropriate. Articles were added until 30 August 2016. Overall, 20 articles were selected for review including 10 in vitro, eight in situ and two clinical studies.

RESULTS

Copper surfaces were found to have variable antimicrobial activity both in vitro and in situ, although the heterogeneity in the designs and the reporting of the results prevented conclusions from being drawn regarding their spectrum and activity/time compared to controls. Copper effect on HAIs incidence remains unclear because of the limited published data and the lack of robust designs. Most studies have potential conflicts of interest with copper industries.

CONCLUSIONS

Copper surfaces have demonstrated an antimicrobial activity but the implications of this activity in healthcare settings are still unclear. No clear effect on healthcare associated infections has been demonstrated yet.

A Perspective on the Principles of Integrity in Infectious Disease Research

The medical literature is prone to overstating results, a condition not thoroughly recognized among policymakers. This article sets forth examples of potential problems with research integrity in the infectious disease literature. We describe articles that may be spun, categories lumped together in hopes of creating a significant effect (and sometimes an insignificant one), changes in metrics, and how trials may fail because of suboptimal interventions. When examined together, the examples show that the problems are widespread and illustrate the difficulty associated with interpreting medical research. The state of the current medical literature makes it of utmost importance that all sections of the manuscript are read, including associated letters to the editors and information on ClinicalTrials.gov before authors' recommendations are accepted.

Infection control measures to decrease the burden of antimicrobial resistance in the critical care setting

PURPOSE OF REVIEW

The prevalence of multidrug-resistant organisms (MDROs) in ICUs is increasing worldwide. This review assesses the role of infection control measures, excluding antibiotic stewardship programs, in reducing the burden of resistance in ICUs.

RECENT FINDINGS

The knowledge base about the effect of increased hand hygiene compliance in reducing the burden of methicillin-resistant Staphylococcus aureus in ICUs has been improved. Universal decolonization with chlorhexidine body washing was associated with significant reduction in MDRO prevalence, but vigilance for emerging chlorhexidine resistance is required. A significant reduction of resistance for Gram-negative bacilli has been demonstrated with the use of selective decontamination, but further clinical trials are necessary before definitive conclusions can be drawn regarding long-term risk/benefit ratios.

SUMMARY

In the recent years, several high-quality clinical studies have assessed the ability of various infection control measures in reducing the burden of antimicrobial resistance. Significant progress has been made in identifying interventions effective in preventing transmission of MDROs in ICUs, in particular, decolonization. However, it still remains impossible to determine the exact and relative importance of different infection control measures. Any approach must ultimately be tailored to the local epidemiology of the targeted ICU.

Hydrogen peroxide room disinfection--ready for prime time?

Non-manual techniques for terminal disinfection of hospital rooms have gained increasing interest in recent years as means to reduce transmission of multidrug-resistant organisms (MDROs). A prospective crossover study by Blazejewski and colleagues in five ICUs of a French academic hospital with a high prevalence of MDRO carriers showed that two different hydrogen peroxide (H₂O₂)-based non-touch disinfection techniques reduced environmental contamination with MDROs after routine cleaning. This study provides further evidence of the ‘in use’ bioburden reduction offered by these techniques. Before H₂O₂-based non-touch disinfection can be recommended for routine clinical use outside specific outbreak situations, further studies need to show whether the environmental contamination reduction provided by these techniques is clinically relevant and results in reduced cross-infections with MDROs.

What's trending in the infection prevention and control literature? From HIS 2012 to HIS 2014, and beyond

This is an informal review of some of the trends in the infection prevention and control literature since the last Healthcare Infection Society (HIS) conference in late 2012. Google Trends was used to investigate how the volume of interest in various infection control topics had changed over time. Ebola trumped all the others in Google searches, reflecting a surge of publications in the literature. Aside from Ebola, other trends in the infection prevention and control literature covered in this article include Middle East Respiratory Syndrome (MERS) coronavirus, universal versus targeted interventions, faecal microbiota transplantation, whole genome sequencing, carbapenem-resistant Enterobacteriaceae, and some aspects of environmental science. The review ends with an attempt to predict some of the trends in the infection prevention and control literature between now and the next HIS conference in 2016.

Controlling hospital-acquired infection: focus on the role of the environment and new technologies for decontamination

There is increasing interest in the role of cleaning for managing hospital-acquired infections (HAI). Pathogens such as vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), multiresistant Gram-negative bacilli, norovirus, and Clostridium difficile persist in the health care environment for days. Both detergent- and disinfectant-based cleaning can help control these pathogens, although difficulties with measuring cleanliness have compromised the quality of published evidence. Traditional cleaning methods are notoriously inefficient for decontamination, and new approaches have been proposed, including disinfectants, steam, automated dispersal systems, and antimicrobial surfaces. These methods are difficult to evaluate for cost-effectiveness because environmental data are not usually modeled against patient outcome. Recent studies have reported the value of physically removing soil using detergent, compared with more expensive (and toxic) disinfectants. Simple cleaning methods should be evaluated against nonmanual disinfection using standardized sampling and surveillance. Given worldwide concern over escalating antimicrobial resistance, it is clear that more studies on health care decontamination are required. Cleaning schedules should be adapted to reflect clinical risk, location, type of site, and hand touch frequency and should be evaluated for cost versus benefit for both routine and outbreak situations. Forthcoming evidence on the role of antimicrobial surfaces could supplement infection prevention strategies for health care environments, including those targeting multidrug-resistant pathogens.

Surface micropattern limits bacterial contamination

BACKGROUND

Bacterial surface contamination contributes to transmission of nosocomial infections. Chemical cleansers used to control surface contamination are often toxic and incorrectly implemented. Additional non-toxic strategies should be combined with regular cleanings to mitigate risks of human error and further decrease rates of nosocomial infections. The Sharklet micropattern (MP), inspired by shark skin, is an effective tool for reducing bacterial load on surfaces without toxic additives. The studies presented here were carried out to investigate the MP surfaces capability to reduce colonization of methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) compared to smooth control surfaces.

METHODS

The MP and smooth surfaces produced in acrylic film were compared for remaining bacterial contamination and colonization following inoculation. Direct sampling of surfaces was carried out after inoculation by immersion, spray, and/or touch methods. Ultimately, a combination assay was developed to assess bacterial contamination after touch transfer inoculation combined with drying (persistence) to mimic common environmental contamination scenarios in the clinic or hospital environment. The combination transfer and persistence assay was then used to test antimicrobial copper beside the MP for the ability to reduce MSSA and MRSA challenge.

RESULTS

The MP reduced bacterial contamination with log reductions ranging from 87-99% (LR = 0.90-2.18; p < 0.05) compared to smooth control surfaces. The MP was more effective than the 99.9% pure copper alloy C11000 at reducing surface contamination of S. aureus (MSSA and MRSA) through transfer and persistence of bacteria. The MP reduced MSSA by as much as 97% (LR = 1.54; p < 0.01) and MRSA by as much as 94% (LR = 1.26; p < 0.005) compared to smooth controls. Antimicrobial copper had no significant effect on MSSA contamination, but reduced MRSA contamination by 80% (LR = 0.70; p < 0.005).

CONCLUSION

The assays developed in this study mimic hospital environmental contamination events to demonstrate the performance of a MP to limit contamination under multiple conditions. Antimicrobial copper has been implemented in hospital room studies to evaluate its impact on nosocomial infections and a decrease in HAI rate was shown. Similar implementation of the MP has potential to reduce the incidence of HAIs although future clinical studies will be necessary to validate the MP's true impact.