Control and mitigation of healthcare-acquired infections: designing clinical trials to evaluate new materials and technologies

Reducing the Effectiveness of Ward Particulate Matter, Bacteria and Influenza Virus by Combining Two Complementary Air Purifiers

Air purifiers should pay much attention to hospital-associated infections, but the role of a single air purifier is limited. The goal of this study was to evaluate the effectiveness of the combined application of the nonequilibrium positive and negative oxygen ion purifier (PNOI) and the high-efficiency particulate air filter (HEPA) on a complex, polluted environment. Two of the better performing purifiers were selected before the study. The efficacy of their use alone and in combination for purification of cigarette particulate matter (PM), Staphylococcus albicans, and influenza virus were then evaluated under a simulated contaminated ward. PNAI and HEPA alone are deficient. However, when they were combined, they achieved 98.44%, 99.75%, and 100% 30 min purification rates for cigarette PM, S. albus, and influenza virus, respectively. The purification of pollution of various particle sizes and positions was optimized and reduced differentials, and a subset of airborne influenza viruses is inactivated. Furthermore, they were superior to ultraviolet disinfection for microbial purification in air. This work demonstrates the strong purification capability of the combined application of these two air purifiers for complex air pollution, which provides a new idea for infection control in medical institutions.

Efficacy of a quaternary ammonium compound in reducing coagulase-positive staphylococcal colony counts in veterinary dermatology exam rooms following two cleaning instruction protocols

BACKGROUND

Nosocomial meticillin-resistant (MR) staphylococcal infections are of global concern. Veterinary dermatology exam room surfaces may be a reservoir given the commonness of staphylococcal pyoderma.

HYPOTHESIS/OBJECTIVES

First, efficacy of exam room surface decontamination using a quaternary ammonium compound was assessed after use of two different cleaning instruction protocols. Second, coagulase-positive staphylococcal (CoPS) colony counts were assessed after use of rooms by dogs with pyoderma, and then after cleaning and disinfection.

METHODS AND MATERIALS

In Part I, 10 room surfaces were tagged with a discreet fluorescent dye, Glo Germ, to assess the efficacy of surface cleaning between two Virex II 256-based cleaning protocols. In Part II, CoPS colonies were quantified via 3M Staph Express System. Ten standardised room surfaces were sampled after use by a dog with staphylococcal pyoderma, and immediately after a detailed cleaning and disinfection protocol.

RESULTS

A total of 24 of 100 and 81 of 100 surfaces were completely cleaned by the general and detailed protocols, respectively. The mean number of surfaces adequately cleaned was higher with the detailed protocol (P = 0.003). The detailed protocol reduced CoPS colony counts of eight surfaces (P < 0.01), and not chairs (P = 0.055). No CoPS were isolated from the exam table under a table mat.

CONCLUSIONS AND CLINICAL RELEVANCE

Detailed exam room cleaning and disinfection protocols are recommended to minimise contamination of veterinary exam room surfaces with staphylococci. The appropriate disinfection of chairs necessitates further study.

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.

The impact of comprehensive air purification on patient duration of stay, discharge outcomes, and health care economics: A retrospective cohort study

BACKGROUND

Infectious airborne and surface pathogens constitute a substantial and poorly explored source of patient subclinical illness and infections. With that in mind, a system of advanced air purification technology was designed to destroy the DNA and RNA of all bacteria, fungi, and viruses. This study compares the effects of advanced air purification technology versus high efficiency particulate air filtration with respect to certain metrics of health care economics and resource utilization at a large, community-based, urban hospital. Our hypothesis was that the use of the advanced air purification technology would decrease health care durations of stay, lead to fewer nonhome discharges, and decrease hospital charges.

METHODS

After the installation of advanced air purification technology, 3 resultant air purification "zones" were established: zone C, a control floor with high efficiency particulate air filtration; zone B, a mixed high efficiency particulate air and advanced air purification technology floor; and zone A, a comprehensive advanced air purification technology remediation. This study included nonbariatric surgical patients admitted to any zone between December 2017 and December 2018, with reported case mix index on discharge. We analyzed hospital duration of stays, discharge destination, and hospital charges with adjustment for severity of illness using the case mix index. The likelihood of mortality, health care-associated infection, and readmission for each study zone was examined using logistic regression adjusting for case mix index, age, sex, and source of admission.

RESULTS

The study included 1,002 patients across the 3 zones, with mean age of 55.8 years (53.7% female), average case mix index of 1.98, and mortality of 1.7%. Compared with zone C, patients in zones A and B demonstrated decreased hospital stays, a greater percentage of home discharges (86.5-87.8% vs 64.7%), and less hospital charges. In addition, logistic regression modeling performed on 999 study patients showed that the likelihood of mortality, hospital-acquired infections, and readmissions did not differ among the 3 zones. A trend toward a lesser incidence of hospital-acquired infections was noted in zones A and B (0.40% and 0.48%, respectively) when compared with zone C (0.63%).

CONCLUSION

Patients in the advanced air purification technology zones demonstrated statistically significant improvements in durations of stay, discharge to home, and costs after adjusting for case mix index. In addition, a trend toward fewer hospital-acquired infections in advanced air purification technology zones was noted. These findings suggest that environmental factors may affect key clinical and economic outcomes, supporting further research in this important and largely unexplored area.

ATP bioluminescence values are significantly different depending upon material surface properties of the sampling location in hospitals

BACKGROUND

Our previous study into assessing hospital cleanliness in Japan by two common methods, ATP bioluminescence and the stamp agar method, revealed considerable variability in the data of both methods (BMC Research Notes, 7: 121, 2014). To investigate the reason(s) for the variability, we reanalyzed the data (n = 752) from the point of view of the material surface properties of sampling sites.

METHODS

Data obtained from surfaces with unknown properties and different purposes such as floor were omitted, and the remaining data (n = 488) were used for this study. The material surface properties on sampling sites were divided into six categories: melamine coated (n = 216), vinyl chloride (n = 16), stainless steel (n = 144), wood (n = 63), and acrylonitrile-butadiene styrene resin coated (n = 48). The data between individual material properties were compared.

RESULTS

The ATP values of high-touch places were significantly different depending on the type of surface, but no significant difference in stamp values between material properties was seen, indicating that in contrast to stamp values, ATP-accumulation more depends on the physical properties of the material surface such as electronic charges or roughness. To confirm this, we assessed a degree of roughness on vinyl chloride material surface (disutilized floor samples actually used for each of the hospitals) by observation with scanning electron microscope (SEM). As a result, SEM observation similarly revealed considerable roughness on the materials, which may allow microbes to contaminate the materials without noticing it.

CONCLUSION

Material properties must be considered when evaluating hospital cleanliness with ATP values, and provide a strong warning into evaluating hospital cleanliness.

Relationships among cleaning, environmental DNA, and healthcare-associated infections in a new evidence-based design hospital

OBJECTIVE

Hospital environments influence healthcare-associated infection (HAI) patterns, but the role of evidenced-based design (EBD) and residual bacterial DNA (previously thought to be clinically inert) remain incompletely understood.

METHODS

In a newly built EBD hospital, we used culture-based and culture-free (molecular) assays, pulsed-field gel electrophoresis (PFGE), and whole-genome sequencing (WGS) to determine: (1) patterns of environmental contamination with target organisms (TOs) and multidrug-resistant (MDR) target organisms (MDR-TOs); (2) genetic relatedness between environmentally isolated MDR-TO and those from HAIs; and (3) correlation between surface contamination and HAIs.

RESULTS

A total of 1,273 high-touch surfaces were swabbed before and after terminal cleaning during 77 room visits. Of the 2,546 paired swabs, 47% had cultivable biomaterial and 42% had PCR-amplifiable DNA. The ratios of TOs detected to surfaces assayed were 85 per 1,273 for the culture-based method and 106 per 1,273 for the PCR-based method. Sinks, toilet rails, and bedside tables most frequently harbored biomaterial. Although cleaned surfaces were less likely to have cultivable TOs than precleaned surfaces, they were not less likely to harbor bacterial DNA. The rate of MDR-TOs to surfaces swabbed was 0.1% (3/2546). Although environmental MDR-TOs and MDR-TOs from HAIs were genetically related by PFGE, WGS revealed that they were unrelated. Environmental levels of cultivable Enterococcus spp. and E. coli DNA were positively correlated with infection incidences (P<.04 and P<.005, respectively).

CONCLUSION

MDR-TOs were rarely detected during surveillance and were not implicated in HAIs. The roles of environmental DNA and EBD, particularly with respect to water-associated fixtures or the potential suppression of cultivable environmental MDR-TOs, warrant multicenter investigations.

Copper surfaces reduce the rate of healthcare-acquired infections in the intensive care unit

OBJECTIVE. Healthcare-acquired infections (HAIs) cause substantial patient morbidity and mortality. Items in the environment harbor microorganisms that may contribute to HAIs. Reduction in surface bioburden may be an effective strategy to reduce HAIs. The inherent biocidal properties of copper surfaces offer a theoretical advantage to conventional cleaning, as the effect is continuous rather than episodic. We sought to determine whether placement of copper alloy-surfaced objects in an intensive care unit (ICU) reduced the risk of HAI. DESIGN. Intention-to-treat randomized control trial between July 12, 2010, and June 14, 2011. SETTINg. The ICUs of 3 hospitals. PATIENTS. Patients presenting for admission to the ICU. METHODS. Patients were randomly placed in available rooms with or without copper alloy surfaces, and the rates of incident HAI and/or colonization with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) in each type of room were compared. RESULTS. The rate of HAI and/or MRSA or VRE colonization in ICU rooms with copper alloy surfaces was significantly lower than that in standard ICU rooms (0.071 vs 0.123; P = .020). For HAI only, the rate was reduced from 0.081 to 0.034 (P = .013). CONCLUSIONs. Patients cared for in ICU rooms with copper alloy surfaces had a significantly lower rate of incident HAI and/or colonization with MRSA or VRE than did patients treated in standard rooms. Additional studies are needed to determine the clinical effect of copper alloy surfaces in additional patient populations and settings.

Control and mitigation of healthcare-acquired infections: designing clinical trials to evaluate new materials and technologies

Hospitals clean environmental surfaces to lower microbial contamination and reduce the likelihood of transmitting infections. Despite current cleaning and hand hygiene protocols, hospital-acquired infections (HAIs) continue to result in a significant loss of life and cost the U.S. healthcare system an estimated $45 billion annually. Stainless steel and chrome are often selected for hospital touch surfaces for their "clean appearance," comparatively smooth finish, resistance to standard cleaners, and relative effectiveness for removing visible dirt during normal cleaning. Designers use wood surfaces for aesthetics; plastic surfaces have become increasingly endemic for their relative lower initial cost; and "antimicrobial agents" are being incorporated into a variety of surface finishes.This paper concentrates on environmental surface materials with a history of bactericidal control of infectious agents and focuses on the methods necessary to validate their effectiveness in healthcare situations. Research shows copper-based metals to have innate abilities to kill bacteria in laboratory settings, but their effectiveness in patient care environments has not been adequately investigated. This article presents a research methodology to expand the evidence base from the laboratory to the built environment. For such research to have a meaningful impact on the design/specifying community, it should assess typical levels of environmental pathogens (i.e., surface "cleanliness") as measured by microbial burden (MB); evaluate the extent to which an intervention with copper-based materials in a randomized clinical trial affects the level of contamination; and correlate how the levels of MB affect the incidence of infections acquired during hospital stays.