Distance, Duration, Disease - and Location

1 June

DISTANCE, DURATION, DISEASE, and LOCATION (D₃L).

Introductory Risk Assesment 101

Dog trainers speak of the 3D’s of distance, duration, and distractions (sometimes with ‘difficulty’ thrown in). Now we have the problem of coming up with a similar way to remember the factors associated with opening the economy and facing up to a possible endemic level of COVID-19.

These factors include distance, duration, disease, and location.

As we begin to re-open, how are those decisions made by our local governments and by ourselves?

Remember that this epidemic rapidly became a pandemic and, most likely, at some time in the future, COVID-19* will become endemic. This means that the novel Coronavirus and the disease it causes, COVID-19, will remain with us at a much lower level.

1. DISTANCE

Keep your distance from people. If you are out for a dog walk and see someone coming, cross the street or step onto the grass and turn your head away. Remember the safe distance was increased early from three feet to six feet.

How far away is six feet?

The length of a regular leash or the length of two golden retrievers or twice the distance of your outspread arms (the distance from one outspread arm to the tip of your nose is about a yard [three feel]).

Do you notice that some people stand too close to you but you are too embarrassed to either ask them to maintain ‘social distance’ or to move away yourself? It is not a matter of ‘feeling uncomfortable’ but of feeling safe. Just do it!

Try turning at least your head away if you pass someone in the grocery store. This may be easier for introverts – to avert one’s gaze – than for extroverts and also easier if the other person is not too interesting-looking.

More virus can be spread further with a sneeze or a cough than with speaking or merely breathing, but even with speaking and breathing. Also, with forced exhalation (sneeze, cough, speaking, breathing – in that order), the particles are forced horizontally more than vertically downward at first. Eventually they all do travel downwards and land on surfaces which is why we must not forget about disinfecting surfaces often (doorknobs, fridge handles, faucets, phones, remotes, etc.)

2. DURATION

Duration refers to the amount of time spent in the vicinity of another person. For example, the choir practice** in Skagit County, Washington, on 10 March 2020, lasted 2 ½ hours. Sixty-one people took part including one asymptomatic person, resulting in 32 confirmed cases, 20 probable cases, 3 hospitalizations, and 2 deaths.

Remember the Ten

The magic number seems to be 10*** minutes. After 10, your chances of ‘exchanging’ viral air with someone increases. People in crowded restaurants lingering over a great meal with close friends or employed in open floorplan seating offices (without even partial walls) where one works  for eight hours are especially vulnerable.

Strive for Five!

So, although the magic number may be ten minutes, strive for five!

How about Grocery Shopping?

Grocery stores tend to be large and shoppers tend to keep moving. Many stores have one-way aisles now (I actually met a man who apologized for going the wrong way! It turns out he had been chastised earlier for doing this by another shopper.) Health professionals suggest you write out your list and shop quickly, preferable with a credit card and checking yourself out along with bagging yourself. The fewer interactions, the better.

On the other hand, employees in stores are in the same workspace (although large) for several hours and pass by numerous people (although for very short periods of time). They are, however, and fortunately, often sanitizing. We are learning.

3. DISEASE

We know by now that after contracting (inhaling) the virus, it can take from 2-14 days or more for enough of the virus to replicate to show symptoms. The average is 4-5 days. So, if the person next to you is infected but doesn’t yet know it, the situation is potentially dangerous. Therefore, suspect everyone of being infected, even if they have tested negative for the virus – a test is only a snapshot in time and means that the person did not have COVID-19 at the time the sample was taken. The next day, that person could have enough viral particles to show symptoms.

More virus can be spread further with a sneeze or a cough than with speaking or merely breathing, but even with speaking and breathing. Also, with forced exhalation (e.g., a sneeze), the particles travel horizontally more than vertically downward at first. So, mask up to deflect the virus away from others.

And let’s not forget the weather or air currents.

4. LOCATION

Stay outside when possible. If you are inside, open the windows for cross-ventilation: do not depend on AC or heating that merely recycles the same old air. Most air conditioning systems currently do purify the air or bring in air from the outside as well as cool it and circulate it.

So, if you must go out to eat, look for open-air seating or use take-out (take-home or eat in your car). Maintain social distance. Wear a mask to protect others and to deflect air downward rather than outward. And, of course, wash your hands (more on that later) and Stay Home, Stay Safe!

Check back here (I may not have time to write such long COVID-19 blogs every day, though, like yesterday and today) for information on risk assessment, the biology of viruses, what is a temperature, where not to touch on your face, symptoms, and the art and science of hand-washing!

Yesterday: Is it really about re-opening the economy? An ex-geneticist speaks.

(Graphics: http://clipart-library.com/coronavirus-clipart.html)

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*COVID -19 – COronaVIrus Disease. The 19 refers to the year 2019, when the disease was first detected.

**CDC: Morbidity and Mortality Weekly Report, 15 May 2020, 69 (19): 606-610

*** https://www.erinbromage.com/post/the-risks-know-them-avoid-them