By Kayleigh Cox-Nowak – Technical Support Manager, Schülke & Mayr UK Ltd.
The cleaning and disinfection of environmental surfaces and equipment in hospitals is an essential component of infection prevention. Effective disinfection should ensure that surfaces are hygienically clean and free of pathogens in sufficient numbers not to transmit infection. This has never been more important than in the current COVID-era.
It is known that the hospital environment is often a mediator of infection transmission and fomites can act as reservoirs, enhancing the ability of pathogens to be transmitted between staff and patients [Kraay, 2018]. Under laboratory conditions, SARS-CoV-2 has been found to remain viable on some surfaces for days. The virus was found to be more stable on plastic and stainless steel than on copper and cardboard, and viable virus was detected up to 72 hours after application to these surfaces [van Doremalen, 2020].
Although the survival of pathogens depends on a number of factors, adequate disinfection of the environment and equipment associated with patient care is essential, to minimise transmission. An efficient disinfection process should always include a precleaning step to remove organic materials. Cleaning physically removes soiling and contamination, including some microorganisms. It is a vital step before disinfection, but does not necessarily destroy all microorganisms, even if a surface looks clean.
To date, the single perfect product for all healthcare disinfection has not been found and there is a wide array of disinfectants that offer a range of characteristics [Rutala, 2014]. Disinfectant wipes are often the first choice for cleaning in the clinical setting, but the use of wipes without sufficient antimicrobial activity against target pathogens can result in poor disinfection of surfaces. This may lead to the spread of pathogens from one surface to another [Boyce, 2016]. Wipes should be certified to the ‘gold standards’ EN16615 and EN14476, and used correctly according to the manufacturer’s instructions.
The type of surface being cleaned or disinfected can affect the completeness with which pathogens are removed [Boyce, 2016]. Therefore, there are situations when using a different product type, such as a spray liquid, may be more effective than a wipe. Uneven surfaces or corners may be difficult to adequately clean and disinfect, meaning there may be gaps in coverage. Spraying directly onto these hard-to-reach areas makes pathogen removal easier.
The amount of disinfectant left on the surface is important, as it determines the concentration of active ingredients delivered to the surface. Below a certain amount of liquid per surface area, the desired antimicrobial affect will not be achieved. “Damp dusting” using a disposable disinfectant wipe will not result in the desired antimicrobial reduction, as the surface will not remain wet for the necessary contact time with an appropriate use dilution of the disinfectant [Rutala,2014]. Directly spraying a surface means that it is likely to remain wet with the disinfectant staying in contact with the surface for longer.
There are also environmental benefits of using a spray applied with a re-usable wipe that is laundered after use. The new NHS sustainability targets set out in the 2019 NHS Long Term Plan, commit to delivering improvements including the reduction of single use items and reducing waste throughout the NHS supply chain. Using a spray liquid and a re-usable cloth could make a valuable contribution towards this target.
Effective surface cleaning will continue to play a key role in the reduction of infection transmission. It is likely that hospitals will need more than one type of cleaner / disinfectant to ensure maximum efficacy particularly in the current pandemic. A spray has many benefits to consider when risks cannot afford to be taken.
References
Boyce JM. Modern technologies for improving cleaning and disinfection of environmental surfaces in hospitals. Antimicrob Resist Infect Control. 2016;5:10. Published 2016 Apr 11. doi:10.1186/s13756-016-0111-x
van Doremalen N, Bushmaker T, Morris DH, Holbrook MG, Gamble A, Williamson BN, Tamin A, Harcourt JL, Thornburg NJ, Gerber SI, Lloyd-Smith JO, de Wit E, Munster VJ. Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. N Engl J Med. 2020 Apr 16;382(16):1564-1567
Kraay, A.N., Hayashi, M.A., Hernandez-Ceron, N. et al. Fomite-mediated transmission as a sufficient pathway: a comparative analysis across three viral pathogens. BMC Infect Dis 18, 540 (2018).
Rutala WA, Weber DJ. Selection of the ideal disinfectant. Infect Control Hosp Epidemiol. 2014 Jul;35(7):855-65. doi: 10.1086/676877. Epub 2014 May 29. PMID: 24915214.
