Thanks to Dr Kayleigh Cox-Nowak – Technical Support Manager, schülke UK, for sharing this insight with Hospital Hub
Healthcare associated infections (HAIs) remain an issue of considerable concern. HAIs, also known as “nosocomial” infections are defined as infections that occur in patients during the process of care in a hospital or other healthcare facility, which was not present or incubating at the time of admission. Such infections increase morbidity and mortality, as well as presenting significant extra costs [Protano, 2019].
The current pandemic has focussed additional attention on HAIs. Infection prevention practices include the safe management and cleaning of the healthcare environment. Recent advice from the NHS states that the ‘frequency of cleaning of both the environment and equipment in care (patient) areas should be increased to at least twice daily, this includes frequently touched sites/points and communal facilities such as shared toilets.’ [NHS, 2021].
This advice is essential as it is documented that pathogens can survive on environmental surfaces for an extended period of time. Also, transmission via an individual touching a contaminated surface has been shown to be possible [Kraay, 2018]. A recent report on the persistence of various coronaviruses on different surfaces showed viral survival from 2 hours to 9 days [Kampf, 2020]. A study specifically examining SARS-CoV-2 found the virus, which causes COVID-19, is stable on plastic and stainless steel for up to 72 hours, on copper for up to 4 hours and cardboard up to 24 hours under laboratory conditions [van Doremalen, 2020].
Bacteria also demonstrate significant survival times on hospital surfaces. Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) have been shown to survive for days and even weeks on environmental surfaces in healthcare facilities [Boyce, 2007].
Although the survival of pathogens on surfaces depends on a number of environmental factors, the underlying ‘risk’ of exposure presented to healthcare staff and patients should not be underestimated. Effective cleaning and disinfection of the environment and equipment associated with patient care is imperative, to minimise the risk of cross infection.
In practice, this means that a single wipe across a contaminated surface may not always be sufficient to deactivate potentially transmissible pathogens. There is evidence to suggest that two wipes of a surface is more beneficial than a single wipe on a contaminated surface. Research has demonstrated that when a single wipe was followed by a second wipe, an extra 1- to 3-log10 reduction in pathogens (viruses and bacteria) was achieved on stainless steel surfaces [Tuladhar, 2012]. This led the researchers to conclude ‘Precleaning before disinfection of the contaminated surfaces is recommended.’
Likewise, the Centre for Disease Control and Prevention (CDC) states that cleaning is the necessary first step of any disinfection process. If a surface is not cleaned first, the disinfection process is compromised [CDC, 2003]. Cleaning is a form of decontamination that renders the environmental surface safe to handle by removing organic matter, salts, and visible soils, all of which may interfere with microbial inactivation [CDC, 2003].
However, it should be remembered that the efficacy of cleaning and disinfection is determined not only by the intrinsic effectiveness of the method applied but also by the appropriateness of the surfaces treated [Tuladhar, 2012]. There have been recommendations that the choice of cleaning materials and the methods employed should focus on the type of surface (including surface sensitivity to detergents) and also its actual location. Reducing the infective load on critical spots such as doorknobs, handles, light switches, and other frequently touched surfaces is more likely to have a profound impact on transmission than disinfecting rarely touched surfaces [Tuladhar, 2012].
The CDC recommends taking certain factors into consideration before selecting the optimum product and procedure for healthcare environmental surfaces. These include the type of surface, the amount of soil present and the likely contamination by microorganisms. [CDC, 2003]. The CDC divides environmental surfaces into two categories: medical equipment surfaces (knobs or handles on haemodialysis machines, x-ray machines, instrument carts) and housekeeping surfaces (e.g., floors, walls, and tabletops).
The Robert Koch Institute (RKI) classifies hospital surfaces according to risk. The likelihood of direct contact and possible contamination with pathogens on near-patient surfaces or surfaces with frequent skin/hand contact is higher than surfaces significantly further away from patients.
Areas with ‘low infection risk’ are classified as those furthest away from patients and include staircases, offices and corridors. Areas posing a ‘greater infection risk’ include general wards, maternity and outpatient areas. ‘Highest infection risk’ areas include operating theatres and intensive care units [RKI, 2002].
Routine bedside disinfection is recommended for near-patient surfaces to restrict the spread of pathogens during care and treatment. It should include surfaces which are likely to have been contaminated with pathogen-containing material, even if this is not visible. [RKI, 2002]. Cleaning without routine disinfection can be employed for surfaces without frequent hand or skin contact by staff or patients. Such surfaces include floors and walls. Cleaning with disinfection should be focused on the most critical areas which are the surfaces mainly involved in pathogen transmission [RKI, 2002].
Therefore when selecting a disinfectant for use in a healthcare setting, ideally it should have some of the following properties: [Rutala, 2014]
Disinfectant wipes are often convenient to use in the hospital environment, but they vary considerably in terms of efficacy, contact times and material compatibility. Besides the disinfectant content, consideration should also be given to the material of which the wipe is composed, which is key to achieving effective disinfection. The composition of the wipe needs to be capable of both containing and transferring the optimum amount of disinfectant onto the surface to achieve the antimicrobial effect. Of particular importance is the ability of the wipe to mop up and hold pathogens rather than just spreading them over the wiped area. The EN16615 test is the highest level of testing for antimicrobial wipes under the recognition of the European Standards committee. The test examines the efficacy of the wipe as a whole i.e. the wipe plus the disinfectant component. It is therefore an excellent starting point for wipe selection.
Effective surface cleaning in hospitals has probably never been as important as in the current pandemic. But there are many factors to consider when choosing the optimum cleaning product and using it in practice.
Boyce JM. Environmental contamination makes an important contribution to hospital infection. J Hosp Infect. 2007 Jun;65 Suppl 2:50-4. doi: 10.1016/S0195-6701(07)60015-2. PMID: 17540242.
CDC Guidelines for Environmental Infection Control in Health-Care Facilities (2003)
https://www.cdc.gov/infectioncontrol/guidelines/environmental/references.html accessed 16th March 2021
Kraay ANM, Hayashi MAL et al, Fomite-mediated transmission as a sufficient pathway: a comparative analysis across three viral pathogens BMC Infect Dis. 2018 Oct 29;18(1):540.
Kampf G, Todt D et al, Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents J Hosp Infect. 2020 Mar;104(3):246-251
van Doremalen N et al, Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1, N Engl J Med, 2020 doi:10.1056/NEJMc2004973
NHS, PHE, COVID-19: Guidance for maintaining services within health and care settings Infection prevention and control recommendations, updated 21st January 2021
RKI, Recommendation Of The Commission For Hospital Hygiene And Infection Prevention At The Robert Koch Institute (RKI), Federal Health Gazette Health Research – Health Protection , 2002, 45, 412-415
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.
Tuladhar E, Hazeleger WC, Koopmans M, Zwietering MH, Beumer RR, Duizer E. Residual viral and bacterial contamination of surfaces after cleaning and disinfection. Appl Environ Microbiol. 2012 Nov;78(21):7769-75. doi: 10.1128/AEM.02144-12. Epub 2012 Aug 31. PMID: 22941071; PMCID: PMC3485719.