FACILITIES MANAGEMENT
consult the most up to date European standards. These have been developed and defined through a process of sharing knowledge and building consensus among technical experts.
Enveloped vs. non-enveloped viruses When considering disinfectant selection, some understanding of the nature of viruses is helpful. Coronaviruses including SARS-CoV-2 are known as ‘enveloped’ viruses, whereas viruses including rotavirus and poliovirus are described as ‘non-enveloped.’ Coronaviruses have an outer lipid layer,
which forms a coating or ‘envelope’ which allows the virus to attach to a host cell. Viruses need a living host to be able to multiply. A virus particle attaches to the host cell before penetrating it, then uses the host cell to replicate its own genetic material. That process slowly uses up the host’s
cell membrane and usually leads to cell death. Once the virus has left the host cell it is ready to enter a new cell and multiply again. As the envelope is needed for host cell attachment, loss of this envelope results in loss of infectivity. Research has suggested enveloped viruses have the potential to develop significant environmental resistance, with the ability to survive in different environmental conditions and on different materials found in hospital settings such as aluminium, sterile sponges, latex surgical gloves as well as in biological fluids. That makes human coronaviruses
(HCoVs) ‘a challenging model for the development of efficient means of prevention’,5
underlining the importance
of optimum disinfectant choice. The main function of a disinfectant lies in its ability to kill or inactivate microorganisms. Therefore, a key step in the selection process is ensuring the disinfectant has the required level of biocidal activity. Disinfection manufacturers provide efficacy data relating to both contact time and the required concentration. This data should be based on product testing which is both rigorous and repeatable.
Setting standards In Europe, this means being tested to the European Norms (EN). Despite the UK’s departure from the EU, European Norms will continue to provide ‘gold standard’ tests for disinfectants, for the foreseeable future.
A useful starting point for selecting a
disinfectant for hospital use in the COVID- era is the EN standard named EN14476 (2013+A2:2019). This European Standard specifies the minimum requirements for the virucidal activity of a chemical disinfectant. It applies to areas where disinfection is
114 Chemical laboratory.
medically indicated including patient care in hospitals. A disinfectant which has this EN certification will be effective against enveloped viruses including SARS-CoV-2. Disposable, single-use disinfectant
wipes are a convenient option for surface decontamination in hospitals. The required contact time of a wipe certified to EN14476 should be considered. This is the time required for the
solution to be in contact with pathogens in order to eliminate or inactivate them. The contact time could vary from 30 seconds to five minutes, which is not a practical amount of time in a busy clinical setting).
It is not only the disinfectant content of a wipe which affects efficacy, but also the actual composition and material of the wipe has an impact on the ability of the wipe to mop up and hold pathogens rather than just spreading them over the wiped area. The EN16615: 2015 test provides the
highest level of testing for antimicrobial, ready-to-use wipes. The test examines the efficacy of the wipe as a whole - the wipe itself plus the disinfectant component. It cannot be assumed that all clinical use wipes will be certified to both EN16615 and EN14476. Those which do not comply to both norms may not be fit for purpose, which is not a risk worth taking during a coronavirus pandemic. When referring to European Norms, it is essential to make product comparisons
based on testing to the most up to date standards. Over time, standards become increasingly rigorous, to protect both patients and staff, but there is no mandatory requirement for manufacturers to test to the latest standards. Newer and more rigorous standards may recommend increased disinfectant concentrations and longer contact times, to ensure microbial efficacy.
Choosing the optimum disinfection
product may mean that a number of different ones are required depending on the surface to be cleaned. For example, ethanol shows a significant activity on the human coronavirus5
so a virucidal
disinfector/cleaner containing ethanol, such as mikrozid®
wipes may play a useful
role in the cleaning and disinfection of hard surfaces, particularly as it is effective against enveloped viruses within one minute (EN14476). Conversely, alcohol-free wipes may be
needed to clean and disinfect surfaces sensitive to alcohol like leather, PVC and acrylic glass. A low-alcohol disinfectant may be utilised where a material friendly disinfectant is required such as patient treatment units and sensitive, high-value equipment. Whatever type of disinfectant is selected, it should still meet the requirements defined in EN14476 for virucidal efficacy.
Conclusion Until an effective, universally accessible vaccine is available, it is highly likely that COVID-19 will remain a threat for the foreseeable future. The highest standards of infection prevention in healthcare facilities is therefore essential, including the selection of optimum disinfectants. Referring to the latest EU standards can help simplify the process.
IFHE
References 1 Public Health England. COVID-19: guidance for health professionals, 2020
https://www.gov.uk/government/collections/ wuhan-novel-coronavirus.
2 Kraay ANM, Hayashi MAL, Hernandez-Ceron N 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.
3 Kampf G, Todt D, Pfaender S, Steinmann E et al. Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents. J Hosp Infect 2020; 104 (3): 246-51.
4 van Doremalen N, Bushmaker T, Morris DH et al. Aerosol and surface stability of SARS- CoV-2 as compared with SARS-CoV-1. N Engl J Med 2020; Apr 16; 382 (16): 1564-7. doi:10.1056/NEJMc2004973
Petri dishes.
5 Geller C, Varbanov M, Duval RE. Human Coronaviruses: insights into environmental resistance and its influence on the development of new antiseptic strategies. Viruses 2012; 4 (11): 3044-68.
IFHE DIGEST 2021
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116
