COVID-19 continues to present an unprecedented challenge to care homes, which have been particularly susceptible to outbreaks of the disease. There is increasing evidence about the transmission of SARS-CoV-2 (the virus that causes COVID-19) by people carrying the virus, but never showing any symptoms. It has been estimated that an asymptomatic carrier may infect others for up to three weeks, which makes disease control even more difficult to manage. [1]
Meticulous hand hygiene forms the basis of effective infection prevention, but effective cleaning of surfaces – particularly in the care home environment – is essential. Viruses can survive on environmental surfaces for long periods of time. This means a virus can be spread by a person touching a contaminated surface. Recent research has shown that SARS-CoV-2 has been found to remain on plastic and stainless steel for up to 72 hours, on copper for 4 hours and cardboard up to 24 hours. [2]
SARS-CoV-2 has been found in blood, saliva, tears, cerebrospinal fluid, and conjunctival secretions. The latest advice from the Department of Health is that apart from sweat, all secretions from people with known or suspected COVID-19, should be regarded as potentially infectious. [3]
The risk of transmitting COVID-19 infection from surfaces depends on many factors. These include:
Although the survival of the virus depends on a number of environmental factors, the underlying ‘risk’ of exposure presented to care workers and residents should not be underestimated. Therefore besides good hand hygiene, adequate disinfection of the environment and equipment associated with residents’ care is imperative, to minimise the risk of infection. According to Public Health England, ‘Effective infection prevention and control measures’ are essential to minimise risks. Appropriate cleaning and decontamination of the environment is essential in preventing the spread of this virus.’[3]
Increased frequency of cleaning of general room surfaces will help reduce the presence of viruses and the risk of transmission. The cleaning process will be most effective if the most contaminated areas are cleaned first and a clean to dirty workflow is followed if possible.
An efficient disinfection process should always include a precleaning step, as only clean surfaces can be efficiently disinfected. [5] Cleaning physically removes contamination, including some microorganisms and soiling if present. It is a vital step before disinfection, but does not necessarily destroy all microorganisms, even if a surface looks clean. The subsequent disinfection stage aims to reduce the number of microorganisms present to a level that is unlikely to cause infection.
Before considering the most appropriate surface disinfectants for preventing the spread of the virus, it is worth noting that coronaviruses are classified as ‘enveloped’ viruses, compared to other viruses, such as rotavirus, or poliovirus which are termed non-enveloped. Enveloped viruses possess an envelope or outer coating that is composed of a lipid layer (fat-like substance that is water insoluble). The envelope is needed to help the virus attach to the host cell. If the envelope is destroyed, the virus is no longer infectious.
Public Health England states that: ‘As coronaviruses have a lipid envelope, a wide range of disinfectants are effective’.[3] However, it is known that coronaviruses are potentially capable of developing significant environmental resistance and may be able to survive in different conditions and on different materials for prolonged periods of time. [5]
Generally, disposable wipes containing disinfectant are the first choice for surface cleaning and there are many different products available. It is worth considering exactly what type of disinfectant/chemicals are present in the wipe(s) being used. Wipes may look similar but may not always have similar antimicrobial properties.
To ensure the efficacy of a disinfectant against viruses, there is a recognised microbiological test against enveloped viruses, according to the European Norm (EN) standard named EN14476. A positive result means that the solution within the wipes/tissue will be effective against enveloped viruses. Choosing a wipe with virucidal efficacy against enveloped viruses, combined with mention of EN14476, is a useful indicator for the selection of disinfection wipes.
Passing the EN14476 test means that the disinfectant solution can inactivate viruses like SARS-CoV-2, but what influences the practical application of the wipe is the contact time. This is the time required for the solution to be in contact with pathogens in order to eliminate or inactivate them.
This means that a disinfectant wipe could be EN14476 certified but may require a contact time of 5 minutes compared to another requiring only 30 seconds. A shorter contact time will save time and help simplify the cleaning/disinfection process.
Besides the disinfectant content, consideration should also be given to the material of which the wipe is composed, which is also 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.
Some ranges of wipes are available with different types of disinfectant, so the wipe can be matched to the surface being cleaned. For example, mikrozid®️ universal is a low-alcohol disinfectant which can be used where a material friendly disinfectant is required on sensitive high value equipment like touch screens and tablets.
With no vaccine against COVID-19 likely to be available for at least a year, the prevention of the virus spreading via contaminated surfaces is crucial to help control this virus. Your choice of wipes has never been more important!
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