Thermally induced plasma as a biocidal agent to reduce the risk of nosocomial spread of pathogenic organisms and eliminate malodours in hospitals.

Thermally Induced Plasma as a Biocidal Agent to Reduce the Risk of Nosocomial Spread of Pathogenic Organisms and Eliminate Malodours in Hospitals. Authors Professor James D. Frame FRCS, FRCS(Plast) Claire A. Robinson BSc Introduction Nosocomial sepsis is a leading cause of death in Hospitals and has serious financial and medicolegal implications within healthcare. According to the House of Commons Public Accounts Committee there are an estimated 100,000 cases of Hospital Acquired Infections per annum costing the NHS an estimated £1 Billion and killing approximately 5000 patients per year(1). Burn injured patients and the environment in which they are being cared, is a breeding ground for a vast range of organisms including viruses, fungi and antibiotic resistant organisms that are likely present on most long term survivors with open wounds(2). Ozone generated for a thermal plasma is both a known biocidal and removes malodour and has a hitherto underused role in helping combat both problems (3,4). Any improvement in the working environment will make it safer and more pleasant for both patients and all levels of staff. Burns patients are particularly vulnerable to sepsis and wound colonisation and so risk spreading antibiotic resistant pathogens during visits to operating theatre and other spaces for treatment or special investigations within Hospitals such as MRI units and Physiotherapy Departments. Staff are also likely responsible for some nosocomial transfer between patient and into the community. Burns Units and particularly patient rooms are deliberately kept warm and humid to satisfy patient needs, but so increase an environment conducive to bacterial growth. Fungal growth, including aspergillus sp, is always a risk to burn immunocompromised patients. Staff remain as known vectors of spread (5,6,7,8) despite hand washing and cleaning protocols. A literature review of microflora thriving in high footfall areas within society indicate origins from perineal or faecal source (9,10,11). Viruses and other organisms are not only spread by surface contact, but also by aerosol and droplets released during breathing and coughing. This study investigates the biocidal properties of thermally derived Plasma and its harness into equipment to produce clean air in working environments laden with organisms and/or unpleasant smells. Methodology Preliminary investigations were established to confirm the findings of a literature search. 1. Culture plates were positioned on the floor of a frequently used catering elevator at a Premiership football Club. The intention was to seek information on likely flora inhabiting frequently used spaces, at a time when Coronavirus transmission was of major concern in 2020. 2. Similar fungal and bacterial contamination studies were carried out on escalator handrails at a National Rail Station and at major Outlet Stores, including a well-known Supermarket. 3. We present unpublished data from these core investigations. 4.Test Custom designed devices a) A high quality, CE marked Plasma generating device ( Modunox D, Fourth State MedicineTM) was incorporated into a customised encasement that delivered ozone directly onto a moving escalator handrail (OXONOX Airstair) at a busy railway station. Culture swabs taken pre and post exposure to Plasma produced significant reduction in microbial flora without excess environmental emission of plasma or plasma degradation products. 2. Ozone cleaned air, generated by OXONOX Airlift™, was fanned into a working vertical elevator cabin. The hypothesis tested was that ozone treated air would reduce the risk of direct person to person droplet, or aerosol spread of organisms, including virus in the close contact environment of a busy lift unit. Any excess ozone is effectively removed by a customised Carulite filter (CE marked). The filtered air is then directed vertically downwards into the cabin as cleaned air, so allowing safe and continuous footfall within the elevator. Head-level culture plates were positioned to investigate the effectiveness of the system at reducing airborne microflora. 3. Investigating microbial flora in large closed spaces at risk of airborne and planktonic spread, malodour, and fungal growth in Hospitals and Universities. A device was constructed by OXONOX TM that exchanges air within a closed room for freshened air that has been ozone treated and ozone filtered. This has now been trialled at multiple sites within an Anatomy Department at a leading UK University Medical School and within Hospital Mortuaries in England and Scotland. Results 1. Contact surfaces on escalators and within elevators are contaminated with a host of organisms, mainly gram negative flora, and indicate a poor level of personal hygiene and handwashing. They also highlight ineffective standard cleaning protocols at most sites tested. These surfaces can be effectively and continuously treated with ozone as demonstrated in the results (Fig 1). 2. Air that has passage through an ozone containment device in an operating lift cabin is effective at reducing the microbial load being inhaled by incumbents of the lift. Results show a greater than 96% reduction in airborne bacteria (Fig 1) within an at-risk environment. 3. Malodour and fungal growth is significantly reduced and effectively removed by filtration using an ozonised air exchange device in Hospital and University mortuaries. Results show that the device created a more pleasant and safer environment with significant cost savings on cleaning with lower usage of potentially hazardous biocidal cleaning agents and embalming chemicals . Conclusion Ozone can effectively kill pathogenic bacteria and fungi in the working environment of a burns unit or in at risk closed space environments within a hospital setting including elevators, escalators, waiting areas, treatment areas, toilets and changing areas. Clean air technology utilising plasma in conjunction with existing air exchange practices is more effective at reducing malodour and microbial load than conventional methods alone. Further trials are needed to demonstrate the effectiveness of the device in the clinical environment such as a burns operating theatre where conventional laminar flow and positive or negative pressure air exchange may not actually be as effective as thought in preventing microbial spread from the Operating Theatre into adjacent corridors and rooms especially when doors are opened (12,13,14,15,16). Airspace sited at the positive pressure exits from the operating theatre into the corridors should significantly reduce risk of transferring multi-resistant organisms to patients and staff and thus help reduce the considerable financial burdens created by hospital acquired infection. Applicabity to clinical practice At a time when the risk of contracting sepsis in hospitals is compounded by the emergence of antibiotic resistant organisms and novel highly pathogenic viruses, it is important that we advance our preventative capabilities. Ozone offers an alternative or adjunct to existing services. It is cheap to produce, sustainable and safe when utilised correctly. References 1) House of Commons Health and Social Care Committee. Antimicrobial resistance. Eleventh Report of Session 2017–19. 2018. HC962. 2) J. D. Frame, L. Kangesu, W. M. Malik, Changing Flora in Burn and Trauma Units: Experience in the United Kingdom. The Journal of Burn Care & Rehabilitation.1992; 13: 281–286. 3) Elvis AM, Ekta JS. Ozone Therapy – A Review. J Nat Sci Biol Med. 2011; 2(1): 66–70. 4) Sakudo A, Yagyu Y, Onodera T. Disinfection and Sterilization Using Plasma Technology: Fundamentals and Future Perspectives for Biological Applications. Int. J. Mol. Sci. 2019; 20 : 5216. 5) Casanova L, Alfano-Sobsey E, Rutala WA, Weber DJ, Sobsey M. Virus Transfer from Personal Protective Equipment to Healthcare Employees’ Skin and Clothing. Centers for Disease Control and Prevention (CDC). 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