In part 2 of this article, we looked at ways of minimizing the chance of becoming infected by using physical barriers. In this part, we look at scientifically proven disinfectant and cleaning procedures to help keep you and your family safe
As someone who once worked at length in the fitness industry, the mantra of the best sports facilities was without doubt
‘cleanliness is next to godliness’. And in the current mushrooming epidemic of coronavirus (more strictly SARS-Cov-2 or COVID-19 – but we will use coronavirus here), no mantra could ever be truer. In this article therefore, we will look at ways to reduce the risk of infection by scrupulous hygiene and disinfection methods.
Recap
Before we begin, let’s just recap some key points from
part one and
part two of this article, which provide a scientific context for what we are about to recommend here:
- #Coronavirus is highly infectious with estimates of R0 between 2.2 and 6.7(1,2).
- #Coronavirus can be spread by asymptomatic individuals who feel perfectly well.
- #The virus is spread mainly via droplets (coughing/sneezing etc not only onto you, but also onto surfaces that you might touch) but may also be spread via airborne transmission. This means not only should direct contact with individuals be avoided, any shared touch surfaces should be scrupulously cleaned.
- #To emphasize the above, this virus has a high degree of persistence on inanimate objects(3); thus the virus can readily be transferred from a surface (that has been coughed on sneezed on!) to a route of entry via the hands.
- #The main routes of entry into the body are inhalation into the lungs, or via the epithelial tissues of the mouth, nose or eyes, which are mostly infected by the transfer of viral particles from hands that have touched contaminated surfaces.
Understanding the challenge
Coronavirus is very infectious (ie has a high R0 value), which is why this pandemic is unfolding so quickly. This infectiousness arises as a result of two factors:
- *It can be spread by asymptomatic people who feel apparently well but are yet to develop symptoms. Without severe movement restrictions (ie a lockdown), these people are likely to be spreading the virus widely as they go about their daily life.
- *The virus is robust and persistent. When viral particles are transferred by coughing, breathing or touching to an inanimate surface, they can persist on surfaces for up to nine days(3), massively increasing the risk of subsequent transmission and infection.
Avoiding people can be effectively achieved by social distancing – either by staying at home as much as possible (the best option!), or when trips outside are made, taking all possible precautions to stay at least seven feet away from other people. [we’ll assume at this point that you’ve already stopped using high-risk venues such as gyms and indoor sports venues] However, many people reading this will have no option but to venture out regularly – for example, key workers such as healthcare workers, those in food and fuel delivery services, supermarket employees and those caring for the vulnerable.
Chemical warfare
Each time you venture out of the house, you may be exposed to viral particles. Practicing social distancing or using effective protective barriers such as masks or gloves (
see part two of this article) can only reduce risk so far. Due to the persistence of the virus on surfaces, you need to keep your hands clean,
and the surfaces you touch. This requires various cleaning agents, ranging from good old soap and water to virucidal agents, which can quickly mount a chemical attack to denature viruses on touch surfaces. Research shows that chemically cleaning all touch surfaces is a critically important strategy for reducing the risk of infection with viruses such as influenza and coronaviruses such as SARS-Cov
(4).
The importance of hand washing
No matter how much you clean touch surfaces, they’ll immediately become contaminated again if your hands aren’t clean – putting not only you but others at risk too. Regular and thorough hand washing is therefore an absolutely crucial part of avoiding infection. You should wash your hands:
- #Each and every time after using the toilet.
- #Each and every time before touching or eating food or drinks.
- #Every time you enter the house after being outside – make this the FIRST thing you do!
- #Every time you get into your car.
- #After you handle cash.
- #After you have touched ANY other surface that someone else may have touched such as a door handle, a keypad, a hand rail etc. If you are still at work, these can include:
- -Exit door push bar
- -Drinking fountain button
- -Conference room door handles
- -Men's and women's restroom soap dispenser handles
- -Men's and women's restroom faucet handles
- -Men's and women's restroom door handles
- -Communal office supplies
- -Copiers
- -Microwave
- -Candy jar
- -Refrigerator
- -Coffee pot
- -Break room sink faucet handle
- -Break room soap dispenser handle
- -Break room drawer handles
- -Communal computer station
- -Communal mini-refrigerator handle
When outside the house, hand washing may not be possible, which is when disinfection is required, but we will come onto that shortly.
Soap and water
Hand washing with soap and water has been shown to be more effective at reducing the incidence of hand-transmitted viral infection than using an alcohol rub/gel
(5). This might surprise you but there are two reasons why soap and (warm) water is so effective:
- Soap can dissolve the thin sticky layer of oil on the surface of the hands (known as sebum), which is then washed away by running water. Because the viral particles are mostly attached to this sticky layer, they are rinsed away too.
- The chemical structure of soap can disrupt the envelope of the coronavirus. Once this envelope is disrupted, the virus can no longer function effectively.
YOU don’t wash your hands properly!
Do you know how to wash your hands properly? Most people do not even if they think they do. That’s because it’s easy to miss areas of the hands with normal hand washing, and most are unaware of the techniques involved to ensure cleanliness. Figure 1 reveals which areas of the hands are most frequently missed when washing. In particular, the thumbs, the tips and backs of the fingers and the wrists are often neglected.
Figure 1: Hand washing
In the link below, Dr John Campbell, one of the UK’s leading nurse trainers and practitioners provides a brilliant and practical demonstration of thorough and effective hand washing. All readers are strongly encouraged to spend four minutes of their time watching it. You will be amazed at how all this time you thought you were washing your hands thoroughly, but weren’t!
How to wash your hands – properly!
Better living through chemistry
Although hand washing is an essential part of antiviral hygiene, it’s often not possible to wash your hands when out – for example after using the petrol/gas pump at the filling station, when alighting from public transport, or every time you come into contact with a common touch surface while out. In these cases, disinfection is the best option. This is where a chemical substance is used either on the hands or the touch surface to denature viral particles.
*Hand disinfection – The most commonly used hand disinfectant is ethyl alcohol (plain alcohol) gel. Research shows that as long as the concentration of alcohol is between 62-71%, the gel is effective at denaturing virus particles
(3). The same research also shows that 0.5% hydrogen peroxide or 0.1% sodium hypochlorite (bleach) solution is effective. Alcohol gel however is preferred on hands because its consistency is good for covering all of the hand’s surface, it evaporates rapidly and is relatively non irritating to the skin.
However, as many of you will know, alcohol gel is currently in short supply in the shops. In that case, there is another option – isopropyl alcohol. Like ethyl alcohol, isopropyl alcohol (also known as ‘rubbing alcohol’) has good skin disinfectant properties
(6,7) Even better, it can be purchased relatively cheaply and used to make a hand gel substitute by mixing it with a moisturizing hand cream. The difference is that isopropyl alcohol is most effective at 70% concentration; while you can buy 70% isopropyl alcohol, as soon as you mix it with anything, the concentration drops below 70%. The solution (no pun intended) is to start with 99% isopropyl and mix accordingly – eg 70mls of alcohol and 30mls of hand cream. Take care however – isopropyl alcohol is very flammable! Just to reiterate though, while hand disinfection is recommended when out and about, proper hand washing – if it is possible - is superior.
*Surface disinfection – Although you can clean/disinfect your hands after touching surfaces, you can add an extra layer of defense by disinfecting surfaces before you touch them. And because you’re not putting chemicals onto your skin, there’s a bit more leeway as to what you can use. For surfaces you need to dry rapidly (like your phone screen), 70% isopropyl alcohol is useful. This can be applied via a wipe or a spray followed by wiping.
Isopropyl alcohol wipes are handy; these consist of a wipe impregnated with 70% alcohol. If you cannot get hold of these, you can make your own. Take a pack of plain baby wipes, pull back the seal, and pour in 50-75mls of 80% isopropyl alcohol. The higher % is to account for the fact that there will already be some moisture in the pack. Leave this for a few minutes to allow the alcohol to mix thoroughly then drain out the excess alcohol by inverting the pack. Reseal and you’re good to go. As well as using these wipes for your hands and surfaces, you can use them as chemical barriers – for example, to hold a door handle as you exit a toilet.
You can also buy a cheap sprayer/atomizer and use this to disinfect. You can use either 70% isopropyl alcohol spray or 0.1% sodium hypochlorite (dilute bleach) spray. Most bleach – so long as it is in date – contains 5-6% sodium hypochlorite solution. This needs to be diluted with water accordingly. This can be achieved by adding 98mls of water to 2mls of bleach (20mls bleach to 980mls water). Care - bleach solutions can disproportionate into poisonous free chlorine if mixed with other chemicals; never mix bleach with anything other than water! Be aware too that this solution can bleach certain fabrics.
Whether you choose to wipe or spray will depend on the circumstances. A pack of alcohol wipes can easily be carried in the pocket; a spray bottle of alcohol or sodium hypochlorite solution, less so. Speaking personally, I use sodium hypochlorite spray when refueling the car by giving the pump handle a thorough soaking before handling it. I also use cheap cotton gloves, which are removed afterwards. By contrast, when pushing keypad buttons, elevator buttons, holding shopping trolley handles etc etc, these are wiped thoroughly with alcohol wipes first. In a high risk area – eg a holding a door handle in a public toilet – you can use a combination of procedures; spray, hold handle with wipe, dispose of wipe then alcohol gel for the hands - and of course thorough hand washing as soon as you return home.
Where should I be using disinfection?
In short, any surface that might have been touched in the previous three days should be considered as a potential vector for viral particles. This includes your car and door keys, your phone (clean twice a day with alcohol!) letters, packages and parcels delivered by couriers, food items bought from a supermarket (or any item purchased from any shop for that matter), credit and debit cards used in a cash or pin machine, cash etc. Many of these items may need to be sprayed or wiped before handling (even then, you should wash your hands after handling). Food items present a particular challenge. Cans, bottles, tins, and sealed plastic packaging can all be dipped in dilute bleach water and left to dry on the draining board. Other items can be sprayed with alcohol and then left to dry.
Your house should also be maintained as a ‘clean zone’. Use regular disinfection on all kitchen surfaces, door handles (especially front door), letterbox, light switches, microwave, kettle and fridge/freezer handles, taps, bag handles, car door handles, and anything involved with food preparation or that you touch or someone else might touch. Shoes, coats and bags should be removed near the front door and not taken into the house. A shallow bowl of bleach water can be left outside the front door in which your outdoors shoes can be dipped in before crossing the threshold of the house.
Taken together, these measures might seem excessive. However, remember that this virus is persistent, infectious and one that can bring serious health consequences. The spread of this virus can be dramatically slowed, but only with extreme vigilance. And as responsible citizens, we owe it to those more vulnerable members of society, which will likely include our older relatives, to be vigilant at all times!
References
- J Med Virol. 2020 Mar 5. doi: 10.1002/jmv.25748. [Epub ahead of print]
- Sanche et al 'The Novel Coronavirus, 2019-nCoV, is Highly Contagious and More Infectious Than Initially Estimated' doi.org/10.1101/2020.02.07.20021154
- J Hosp Infect. 2020 Mar;104(3):246-251
- J Hosp Infect. 2016 Mar;92(3):235-50
- BMC Infect Dis. 2017; 17: 47
- Clin Microbiol Rev. 1999 Jan; 12(1):147-79
- Clin Lab Sci. 2005 Summer; 18(3):160-9