Quantifying bacterial transfer from patients to staff during burns dressing and bed changes: Implications for infection control

Metagenomic insights into microbial contamination in critical healthcare environments and the efficacy of a novel "HLE" disinfectant

BACKGROUND

Bacterial contamination on inanimate clinical surfaces is directly linked to severe health problems, especially those caused by multidrug resistant (MDR) pathogens. Here, we evaluated the microbial burden in these environments and tested the efficacy of a novel HLE disinfectant solution.

METHODS

Microbial contamination of healthcare surfaces [Intensive Care Unit (ICU), Long Period Hospitalization Room (LPHR) and Otolaryngology Consultation (OC)] and the efficacy of HLE disinfectant solution were determined analyzing the viable counts on general and selective media, and also by molecular studies focused on metagenomic and specific qPCR.

RESULTS

Different contamination loads were detected with LPHR showing the highest contamination. Treatment with the HLE disinfectant solution curbed the spread of well-adapted pathogens on touched surfaces (ICU, LPHR and OC). Metagenomic analysis of microbial diversity of the Patient Table (most contaminated surface in LPHR) revealed the presence of mainly A. johnsonii and P. putida. Furthermore, functional annotation of toxin, virulence and antibiotic resistance sequences showed a high diversity of Acinetobacter spp. and Pseudomonas spp. In this context, specific qPCR analysis confirmed the efficacy of HLE disinfectant solution against the most prevalent and critical pathogens Pseudomonas sp. and Acinetobacter sp. achieving their complete eradication.

CONCLUSION

Given the persistence of detrimental resistant pathogens, the application of HLE disinfection solution could be a highly beneficial and effective option -used either alone or in combination-for infection prevention and control with the aim to eliminate microbial pathogens and their genes from contaminated contact-surfaces and thus limit the spread to humans and other ecological niches.

Textiles as fomites in the healthcare system

Nosocomial infections or healthcare-associated infections (HAIs) are acquired under medical care in healthcare facilities. In hospital environments, the transmission of infectious diseases through textiles such as white coats, bed linen, curtains, and towels are well documented. Textile hygiene and infection control measures have become more important in recent years due to the growing concerns about textiles as fomites in healthcare settings. However, systematic research in this area is lacking; the factors contributing to the transmission of infections through textiles needs to be better understood. The review aims to critically explore textiles as contaminants in healthcare systems, and to identify potential risks they may pose to patients and healthcare workers. It delineates different factors affecting bacterial adherence on fabrics, such as surface properties of bacteria and fabrics, and environmental factors. It also identifies areas that require further research to reduce the risk of HAIs and improve textile hygiene practices. Finally, the review elaborates on the strategies currently employed, and those that can be employed to limit the spread of nosocomial infections through fabrics. Implementing textile hygiene practices effectively in healthcare facilities requires a thorough analysis of factors affecting fabric-microbiome interactions, followed by designing newer fabrics that discourage pathogen load. KEY POINTS: • Healthcare textiles act as a potential reservoir of nosocomial pathogens • Survival of pathogens is affected by surface properties of fabric and bacteria • Guidelines required for fabrics that discourage microbial load, for hospital use.

Risk factors for nosocomial infections and/or sepsis in adult burns patients: An integrative review

BACKGROUND

In comparison to general trauma patients, loss of skin barrier amongst the burns cohort predisposes them to a higher risk of nosocomial infections and sepsis, and this often leads to unfavourable morbidity and mortality outcomes.

PURPOSE

This integrative review aimed to explore existing literature to identify risk factors related to nosocomial infections and/or sepsis in adult burns patients following hospital admission.

METHODS

Electronic searches for journals published between 2007 and 2021 were performed in CINAHL, Scopus and Medline, and key journals were hand-searched. Inclusion criteria was: (1) peer-reviewed, primary studies; (2) qualitative, quantitative or mixed-methods studies; (3) study participants had sustained burns-related injury and developed nosocomial infections and/or sepsis during the course of hospitalisation. Studies were appraised using the Critical Appraisal Skill Program checklists.

RESULTS

15 studies ranging from 'poor' to 'fair' to 'moderate' quality were included in the final review. Patient factors that contributed to the development of nosocomial infections and/ or sepsis included: (1) Full thickness burns; (2) age; (3) % Total Burns Surface Area; and (4) Herpes Simplex Virus activation. Several provider-system risk factors were identified by 'poor' quality studies and further research is required to substantiate those findings.

DISCUSSION

Findings remained inconclusive due to the lack of 'good' quality studies however, there was an overemphasis on patient-related risk factors instead of healthcare workers or the system. Future research may focus on activation of the latest infection prevention strategies and early enforcement of care bundles. Through identification of related risk factors, it may reduce the incidence of nosocomial infection and/or sepsis post-burns.

The implementation of an infection control bundle within a Total Care Burns Unit

AIM

To evaluate the impact of the implementation of a best practice infection prevention and control bundle on healthcare associated burn wound infections in a paediatric burns unit.

BACKGROUND

Burn patients are vulnerable to infection. For this patient population, infection is associated with increased morbidity and mortality, thereby representing a significant challenge for burns clinicians who care for them.

METHODS

An interrupted time series was used to compare healthcare associated burn wound infections in paediatric burn patients before and after implementation of an infection prevention and control bundle. Prospective surveillance of healthcare associated burn wound infections was conducted from 2012 to 2014. Other potential healthcare associated infection rates were also reviewed over the study period, including urinary tract infections, pneumonia, upper respiratory tract infections and sepsis. An infection prevention and control bundle developed in collaboration between the paediatric burn unit and infection control clinicians was implemented in 2013 in addition to previous standard practice.

RESULTS

During the study period a total of 626 patients were admitted to the paediatric burns unit. Healthcare associated burn wound infections reduced from 34 in 2012 to 0 in 2014 following the implementation of the infection prevention and control bundle. Pneumonia and sepsis also reduced to 0 in 2013 and 2014, however one upper respiratory tract infection occurred in 2013 and urinary tract infections persisted in 2013.

CONCLUSION

The implementation of an infection prevention and control bundle was effective in reducing healthcare associated burn wound infections, pneumonia and sepsis within our paediatric burns unit. Urinary tract infections remain a challenge for future improvement.

Continuous monitoring of aerial bioburden within intensive care isolation rooms and identification of high-risk activities

Background

The spread of pathogens via the airborne route is often underestimated, and little is known about the extent to which airborne microbial contamination levels vary throughout the day and night in hospital facilities.

Aims

To evaluate airborne contamination levels within intensive care unit (ICU) isolation rooms over 10–24-h periods in order to improve understanding of the variability of environmental aerial bioburden, and the extent to which ward activities may contribute.

Methods

Environmental air monitoring was conducted within occupied and vacant inpatient isolation rooms. A sieve impactor sampler was used to collect 500-L air samples every 15 min over 10-h (08:00–18:00 h) and 24-h (08:00–08:00 h) periods. Samples were collected, room activity was logged, and bacterial contamination levels were recorded as colony-forming units (cfu)/m³ air.

Findings

A high degree of variability in levels of airborne contamination was observed across all scenarios in the studied isolation rooms. Air bioburden increased as room occupancy increased, with air contamination levels highest in rooms occupied for the longest time during the study (10 days) (mean 104.4 cfu/m³, range 12–510 cfu/m³). Counts were lowest in unoccupied rooms (mean 20 cfu/m³) and during the night.

Conclusion

Peaks in airborne contamination were directly associated with an increase in activity levels. This study provides the first clear evidence of the extent of variability in microbial airborne levels over 24-h periods in ICU isolation rooms, and found direct correlation between microbial load and ward activity.

Vacuum-assisted closure (VAC®) systems and microbiological isolation of infected wounds

Background

Negative pressure wound therapy is now largely used to treat infected wounds. The prevention and reduction of healthcare-associated infections is a high priority for any Department of Health and great efforts are spent to improve infection control systems. It is assumed that vacuum-assisted closure (VAC®) dressings should be watertight and that all the secretions are gathered in a single container but there is no consistent data on air leakage and possible dispersion of bacteria from the machine.

Methods

We have conducted a prospective experimental study on 10 patients with diagnosis of wound infection to verify whether the filtration process is microbiologically efficient. We compared the bacteria population present in the wound to the one present in the air discharged by the VAC® machine.

Results

This study shows that the contamination of the VAC® machine is considerably lower than the environment or wound contamination.

Conclusions

Negative pressure wound therapy system does not represent a risk factor for healthcare-associated infections.

An in vitro assessment of bacterial transfer by products used in debridement

OBJECTIVE

The aim of this in vitro study was to investigate the transfer of viable Pseudomonas aeruginosa biofilm microorganisms following treatment with debridement tools.

METHOD

The level of viable biofilm microorganisms transferred by debridement tools was compared following treatment that reflected the clinical practice of each product.

RESULTS

A significant level of microorganism transfer was seen in response to the mechanical debridement tool. Minimal transfer of microorganisms was seen when in vitro-established biofilms were treated with hydroresponsive wound dressing + polyhexamethylene biguanide (HRWD+PHMB, HydroClean plus). Less Pseudomonas aeruginosa was recovered from explants exposed to dressings compared with those exposed to debridement tools suggesting that there was less transfer of bacteria by dressings.

CONCLUSION

The reduced transfer of viable microorganisms by HRWD+PHMB may be the result of significant binding and retention of microbes by the superabsorbent polymer within the dressing, together with enhanced sequestered bacterial killing within the dressing by polymer-bound PHMB. The high levels of microbial transfer/transmission seen for debridement tools suggests that, in the clinical setting, a significant level of bacterial spread over the wound surface and/or surrounding skin by these cleansing tools is likely.

Transfer of pathogens to and from patients, healthcare providers, and medical devices during care activity-a systematic review and meta-analysis

OBJECTIVE

The transfer of pathogens may spread antimicrobial resistance and lead to healthcare-acquired infections. We performed a systematic literature review to generate estimates of pathogen transfer in relation to healthcare provider (HCP) activities.

METHODS

For this systematic review and meta-analysis, Medline/Ovid, EMBASE, and the Cochrane Library were searched for studies published before July 7, 2017. We reviewed the literature, examining transfer of pathogens associated with HCP activities. We included studies that (1) quantified transfer of pathogens from a defined origin to a defined destination surface; (2) reported a microbiological sampling technique; and (3) described the associated activity leading to transfer. For studies reporting transfer frequencies, we extracted data and calculated the estimated proportion using Freeman-Tukey double arcsine transformation and the DerSimonian-Laird random-effects model.

RESULTS

Of 13,121 identified articles, 32 were included. Most articles (n=27, 84%) examined transfer from patients and their environment to HCP hands, gloves, and gowns, with an estimated proportion for transfer frequency of 33% (95% confidence interval [CI], 12%-57%), 30% (95% CI, 23%-38%) and 10% (95% CI, 6%-14%), respectively. Other articles addressed transfer involving the hospital environment and medical devices. Risk factor analyses in 12 studies suggested higher transfer frequencies after contact with moist body sites (n=7), longer duration of care (n=5), and care of patients with an invasive device (n=3).

CONCLUSIONS

Recognizing the heterogeneity in study designs, the available evidence suggests that pathogen transfer to HCPs occurs frequently. More systematic research is urgently warranted to support targeted and economic prevention policies and interventions.

The year in burns 2013

Approximately 3415 research articles were published with burns in the title, abstract, and/or keyword in 2013. We have continued to see an increase in this number; the following reviews articles selected from these by the Editor of one of the major journals (Burns) and colleagues that in their opinion are most likely to have effects on burn care treatment and understanding. As we have done before, articles were found and divided into the following topic areas: epidemiology of injury and burn prevention, wound and scar characterization, acute care and critical care, inhalation injury, infection, psychological considerations, pain and itching management, rehabilitation and long-term outcomes, and burn reconstruction. The articles are mentioned briefly with notes from the authors; readers are referred to the full papers for details.

Cold air plasma to decontaminate inanimate surfaces of the hospital environment

The hospital environment harbors bacteria that may cause health care-associated infections. Microorganisms, such as multiresistant bacteria, can spread around the patient's inanimate environment. Some recently introduced biodecontamination approaches in hospitals have significant limitations due to the toxic nature of the gases and the length of time required for aeration. This study evaluated the in vitro use of cold air plasma as an efficient alternative to traditional methods of biodecontamination of hospital surfaces. Cultures of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli, and Acinetobacter baumannii were applied to different materials similar to those found in the hospital environment. Artificially contaminated sections of marmoleum, mattress, polypropylene, powder-coated mild steel, and stainless steel were then exposed to a cold air pressure plasma single jet for 30 s, 60 s, and 90 s, operating at approximately 25 W and 12 liters/min flow rate. Direct plasma exposure successfully reduced the bacterial load by log 3 for MRSA, log 2.7 for VRE, log 2 for ESBL-producing E. coli, and log 1.7 for A. baumannii. The present report confirms the efficient antibacterial activity of a cold air plasma single-jet plume on nosocomial bacterially contaminated surfaces over a short period of time and highlights its potential for routine biodecontamination in the clinical environment.

Role of the Microbial Burden in the Acquisition and Control of Healthcare Associated Infections: The Utility of Solid Copper Surfaces

For more than a century, healthcare has been challenged to keep environmental surfaces clean to control microbes and improve patient outcomes. However despite an annual cost exceeding ten billion dollars cleaning with disinfection has done little to reduce the incidence of healthcare-associated infections (HAI). This chapter will review the scientific evidence delineating the role that the environment and healthcare workers play in the acquisition and movement of the microbes implicated in HAI and how through controlling the microbial burden of the built clinical environment it is possible to mitigate the rate of HAI acquisition. Specifically evidence demonstrating the effectiveness of solid copper surfaces for its ability to continuously limit the concentration of bacteria found on surfaces and objects within the built environment will be reviewed in concert with a discussion of how through the mitigation of the environmental burden copper surfaces are able to concomitantly reduce the incidence of HAI. Insights provided by this chapter are intended to facilitate an understanding and importance of the need to use a comprehensive or systems based approach to fight healthcare associated infections.