11 August 2020 – Feest Isolation Days

Feest Isolation Days – 11 August

“Reflections from self-isolation in Bristol” is the subtitle of this blog. About 5 months of a combination of lockdown then some easing, social distancing, not travelling, no concerts or plays – the ideal opportunity for internal reflection, deep thought, sorting out one’s life – but somehow life has remained busy, full of things to do, I am not sure what deep thoughts or revelations have come to me. There have certainly been some trivial ones, and a lot of learning about a brand new disease. Kathy has primed me to share something of what I have learned about Covid, so that first, then some other thoughts from isolation.

Covid thoughts

It is important to stress that what follows is my personal understanding of what information I can find, it is not a textbook or authoritative statement, so please read it with healthy scepticism!

When Covid first hit us this year it was a new disease, we knew virtually nothing about it, we were ignorant because there was no knowledge available. Many mistakes were made, most countries locked down too late, but in the absence of any real knowledge reluctance to take such a major step which greatly damages people’s lives and the economy was understandable. Neither did we know how Covid spreads, which made it very difficult to take targeted action to prevent it, so we did everything, we stayed home, social distanced, decontaminated anything we touched, (including the mail) and many wore masks if they had to go out.

In the time since this first hit us, much has been learned, but it is difficult to find helpful information amidst all the complex information and false information being spread around. As an individual I want to know how it spreads. What is the risk of meeting people? Is there aerosol or droplet spread? What are the implications of this? Is there really a great risk of contaminant spread? And how many people are there out there in my area who are spreading this virus? – one of the major determinants of what I decide to do. And then…what is the risk to me if I do get the virus? It is only with some answers to these questions that I can make decisions in my life, that I can decide the risk of taking actions that are important to me, and thus whether to do them or not.

When the virus first hit us, we locked down to suppress the peak and stop hospitals being overwhelmed. There was a school of thought, which I admit seemed somewhat attractive, that if we are all going to get it anyway, why not do it quickly and get it over with. This is carefully reviewed in this article (https://www.medscape.com/viewarticle/931474?src=mkm_ret_200728_mscpmrk_covid_overwith_int&uac=365112EK&impID=2477899&faf=1): in essence the idea is flawed as with what we have already learned of treatment, e.g. nursing prone, when to start ventilation if needed, prevention of thrombosis, use of dexamethasone, and some other drugs, the chance of death if severely ill with the virus today is much less than half what it was back in April, and is steadily improving. Anyway, I want to survive to get the vaccine!

The virus enters the body by our respiratory tract, and when we are infectious is excreted from it. There seems now to be a consensus that outside of the hospital setting, the most common way of infection is by close prolonged contact with infected individuals in an enclosed environment, the reason why the major route of spread is within families.

Why is this? There is a great debate about “droplet” or “aerosol” spread. Initially spread was thought to be largely by droplets, large particles typically generated by coughing or sneezing, which rapidly fall to the ground or onto surfaces. This was the basis for the 2 metre rule, droplets fall so fast that beyond 2 metres you are unlikely to inhale them, although surfaces may be contaminated (more on that later).

This always seemed a little simplistic to me, especially when in my garden, I can smell a smoker passing by several metres away the other side of an eight-foot garden wall. Aerosols are much smaller and linger in the air for longer, up to a few hours, and spread farther. Aerosols can be generated by humans, especially when shouting, breathing heavily (e.g. exercise), singing etc. This sounds very scary, but the dose of virus in aerosols is very low, and with any degree of ventilation (including the open air) aerosols are rapidly diluted, so 2 metres was probably still good advice even if for the wrong understanding. Furthermore, in the open exposed to UV rays, the virus in the air only remains infectious for 8-19 minutes, although it may do so for up to 3 or 4 hours indoors. The virus is not one of the most highly infectious ones in the sense that more than a tiny dose is needed to cause clinical infection, some 20 times larger than the dose needed to cause measles. However, if you remain in an enclosed space, breathing and rebreathing the air, the dose you receive may build up and cause illness. This explains some of the major spreading events noted, choirs, gyms, places of worship, meatpacking factories, call centres, some restaurants and factories, and of course families. If aerosol transmission is of any importance, then the wearing of masks when in an enclosed space is a useful, but far from total, protection (https://www.medscape.com/viewarticle/931320 #vp_2). This mode of transmission is now accepted by WHO and by British scientists advising the government as one of the ways in which the virus spreads(https://www.who.int/news-room/commentaries /detail/transmission-of-sars-cov-2-implications-for-infection-prevention-precautions)( https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/907587/s0643-nervtag-emg-role-aerosol-transmission-covid-19-sage-48.pdf).

So what of spread by contamination? This is common in other viruses, including some corona viruses. Droplets contaminate surfaces, someone touches them and then their eyes, nose, or mouth giving the virus entry to their body. What is important to know is the dose needed, and how long the virus remains “viable” when it dries in a surface. An early study suggested the virus could remain infectious for up to 4 hours on copper and some other surfaces, 24 hours on cardboard, but up to 3 days on stainless steel and plastic. However the dose of virus applied to the surfaces in these studies was 100 times that likely to occur in a real situation. In practice contact infectiousness is probably a lot less than feared and does not appear to have been a major route of spread. Although caution and hand washing are still important, we have probably focussed too much on this (this is a very good article https://www.theatlantic.com/ideas/archive/2020/07/scourge-hygiene-theater/614599/?utm_source=facebook&utm_medium=social&utm_campaign=share&fbclid=IwAR1EuJUDB3n6ZVEbMlGnmpXhq4ntFnE3YmZLm1R_ZNKVK98FIBxY6fSQqIo).

A good example of this analysis is an office block in South Korea, where the majority of workers in a call centre (talking loudly, long time, closed spaces) contracted Covid, but less than 1% of a thousand or so other workers in the block got it, despite passing the call centre workers in lifts and corridors, touching the same door handles and lift buttons etc.

Added to considerations on routes of infection is the prevalence of the virus. Bristol has a very low rate, probably less than 1 in 5000 people have it at any time, and the majority of those are not in circulation – they are isolating or unwell at home. The chance of any one random individual I meet here being infectious is less than 1 in 10,000 – but if I went to a large gathering the odds increase dramatically. On top of that, with new understanding in treatment the chance of death if you get the disease is less than half what it was a few months ago.

What does this all mean for me? I am not going to the gym, choir, restaurants or concerts (or even factories and call centres) where we are in close proximity to lots of people breathing the same air for over 15 minutes. We are not flying or using public transport. We wear masks in any public enclosed space. We wash our hands a lot! I happily walk down the street, or go masked to a proper open-air market which is well organised with good spacing, one-way routes etc. I am going fishing, a solitary hobby, but I spray the boat just in case, (obsessional, it has been in the open air at least 12 hours since anyone else was on it). We go walking, we see friends for tea, drinks or even a meal in their or our garden, and with carefully chosen friends who have been as cautious in isolation as we have, we meet inside with a degree of social distancing and windows open. We will go to appropriately organised shops if we need to. Our youngest son who has had the disease visited us for the first time in 8 months: after being on public transport he changed clothes on arrival. We may take a drink in a pub garden or open-air cafe.

With more understanding we are more relaxed and feel able to make our own decisions. Nothing is risk free, but while the prevalence remains low in Bristol, we do feel able to make decisions to do things which seem important enough to us to take the small risks we are beginning to understand. Nevertheless, roll on the vaccine!

Other thoughts!

Every morning we have developed the habit of having tea in bed, with half an orange each. One morning when it was my turn to prepare this, I was separating out the orange segments, there were ten, and I fell to wondering whether all oranges had the same number of segments. 76 six years old and I had never thought about this before! Mr Google informed me that all oranges have ten segments. This seemed an odd number to me, nature is so often binary, cells divide into 2 then 4 then 8 – 2,4, then 8 for nature to appreciate. How on earth did oranges evolve to have 10 segments, a very non-binary number. There are of course a few rogue oranges which lose or gain an odd segment, just like there is the occasional four-leafed clover. Come to think of it, how did clover evolve to have three leaves…………

Then there has been the hay fever season – lots of sneezing. We all sneeze a lot, a complex manoeuvre. It crossed my mind that as often as we do it, we cannot actually do it voluntarily, on demand – are there any other actions like that over which we cannot exert voluntary control. Hiccoughs come a close second, but I can initiate a pretty good imitation…

There is a big industry in hand creams, washing liquids which do or don’t damage your hands. We have been washing our hands furiously the last few months – but the skin has not changed!

Another result of Covid thinking is a forced acceptance of my age. I do not feel older in myself, but at 76, in everything I read about Covid, I find myself in the aged high risk category, the risk stratifications never start at 80 or 85, always 75 or below!

Lockdown has made me realise quite how privileged we are, in our large house and garden, our own little kingdom……