COVID Transmission: Air – Not Touch
You may have enjoyed one of my last blogs which was a joint effort by myself and Dr. David Bergen (well mostly by David) entitled Survival Odds – An Optimistic View.
If you haven’t already read it, you can do so by finding it on our blog page or by clicking here.
I have teamed up with David to bring you some of his research insights into how COVID does and doesn’t spread amongst the population. These observations are very interesting when compared to some of the protocols that have been mandated for “cleaning” your offices. Once again, here are Dr. David Bergen’s words as he shared them with me:
Some thoughts on COVID and what really appears to matter.
Sometime last winter, in the very early days of the COVID-19 pandemic, I read an interesting article about the coronavirus itself. The virus consists of a sphere of protein encasing the RNA that actually causes the infection. The protein sphere has characteristic club-shaped spikes that project from their surface (creating a shape reminiscent of the solar corona, for which it is named).
The article that I was reading explained that the spikes were necessary for the virus to attach to receptor sites on cells in our body. Once latched on, the RNA was transferred into our cells and it hijacked those cells to become a “factory” producing new coronaviruses and so eventually infected the whole body.
What was of interest in this article was a description of how vulnerable the virus was to desiccation or drying out. Once dry, the protein sphere collapses and the RNA is no longer infectious, as the necessary protein spikes can no longer attach to our cells. The initial source of the virus is in the droplets and aerosols that we emit when we talk or cough. These droplets will apparently persist for up to 8 minutes in the air, the aerosols longer, but the research is ongoing. They will also settle on surfaces. However, once the water in the aerosol has evaporated, the RNA enclosed by the now collapsed protein sphere is no longer infectious since the spikes are unable to attach to a host cell.
Surfaces such as paper and cloth were thought to absorb the moisture from aerosols, speeding the drying process, and so would quickly become non-infectious while hard surfaces would take somewhat longer. As a result, I became much less concerned about becoming infected through the transmission of the virus by touching surfaces.
Shortly after this first article, several studies were published and they found that surfaces could be a source of viable RNA for up to 8 days after. This caused me to seriously rethink my earlier assumptions. The world also followed suit, with terms like deep cleaning becoming common in our thinking. Contaminated surfaces were to be feared.
Then, later in the spring, an article appeared in the Globe and Mail: this is an extract from the article:
“Emanuel Goldman’s mother-in-law was driving him up the wall.
“‘Wipe down the groceries. Wipe down the handles of the bags from the people who delivered the food,” he recalls her saying.
Her demands prompted Dr. Goldman, a professor of microbiology, biochemistry and molecular genetics at Rutgers University, to dig into the scientific literature on the transmission of human coronaviruses. What he found confirmed his suspicions: The risk of catching COVID-19 from touching contaminated surfaces and objects – or what scientists call fomites – is “negligible,” he said.”
Later an article appeared in The Atlantic: its title was “Hygiene Theatre Is a Huge Waste of Time”.
It described how much time, energy, and money goes into cleaning and “deep cleaning” surfaces, etc. when in fact, this is not how the virus is transmitted. The virus is transmitted by aerosols from person to person, and under the right conditions, it is very contagious. All the commotion, activity, and cost (the New York subway system is spending $100,000,000 annually “deep cleaning” all of its cars every night) make everyone feel better, but it is not actually accomplishing anything much at all: theatre.
Of interest, I have a well-read MD friend who uses a paper towel when leaving a public washroom. He says: “It’s not for COVID-19. Its spread by touch appears to be negligible. It’s for Norwalk Virus and Rotavirus: these are spread by touch.”
So: what really matters: preventing the spread of the virus through droplets and aerosols from person to person. When you are indoors and out in the world: wear a mask: your mask protects the other person from your droplets and aerosols, and the other person’s mask protects you from their droplets and aerosols.
Also, think about your environment. It appears that a certain “viral load” is necessary to become infected. As well, a higher viral load can make for a worse infection and masks appear to be very effective at reducing viral load. If you share a small, enclosed room with another person who is infected, you have a much higher risk of getting a high viral load than if you are out of doors and the air is constantly being changed by the wind. So: think about your environment, and when in doubt, masks worn by everyone greatly reduce the risk of transmission, and in those rare cases of transmission, the viral load will be greatly reduced.”
Some sources for David’s observations, in addition to Wikipedia:
David Bergen is a dentist with a very unique one operatory office which overlooks Lake Ontario in Port Dalhousie. He also happens to be my dentist and I am honoured to be sharing my blog space with him.