[PLUG-TALK] Covid-19 morbidity/mortality: current numbers

[Keith Lofstrom]

On Tue, Mar 02, 2021 at 07:07:40AM -0800, Rich Shepard wrote:
> The local weatherunderground page presents daily updates of confirmed cases
> (morbidity) and deaths (mortality) in Multnomah County. Over the past year
> these numbers have been low so today I calculated the percentages. Using
> 2020 county population (735,3334) and today's number of confirmed cases
> (31,892) results in a morbidity of 4.34%; the 529 deaths are 1.66% of those
> infected. We're really fortunate to see such low numbers.

Apples and oranges.  The morbidity rate trails the case rate
by weeks (and sometime months), and the case rate trails the
infection rate by more weeks.  A few COVID victims have been
in critical care limbo for many months, a battleground
between clever doctors and a continually mutating RNA virus. 

More important "rates" relate to the proportion of COVID variants.
The UK (B.1.1.7) and South African (B.1.351) variants are a small
fraction of cases in the US today, but the doubling rates of
those fractions are much larger than the doubling rate of the
currently dominant (and less lethal) 501.Y version of COVID. 

In the US, the UK variant is doubling every 5 days, and will
dominate the statistics by April.  There are very few South
African variant infections, but not zero, and some experts
expect those will double faster.  Until our behavior improves,
the doubling rates will continue.  20 doublings is a factor
of one million, which can happen in less than two months.

Think of waves in the ocean - a tsunami is a centimeter scale
surface perturbation far from shore (with a VAST bolus of
slowly moving water and a mile-per-second speed-of-sound
pressure wave) underneath.  As that vast amount of energy
is focused by the upsloping continental shelf, it raises
a much smaller volume of water into ten meter scale surges.
It takes scientific/engineering training to visualize how
an imperceptable change can grow to monster scale.

I ponder the molecular biology of COVID, along with my MD
wife and her colleagues.  We read Science and JAMA and many
online journal articles.  This isn't botany or zoology (I'm
awful at that, my wife much better), but molecular warfare. 
Molecular machine weapons; I'm odd, and can relate to that.

Offlist, I can provide pointers to private youtube videos of 
lectures by a local expert.

I can also compute the case rate versus age and genotype.
At my age, the mortality rate for males is 9%.  With my
peculiar genetics, the mortality rate climbs to 20%
(though my oddball genetics aren't considered by state
regulators).  Diet and exercise reduces my risk. 
My lousy sleep habits increase it.

My extreme paranoia about public interaction drops my rate
a LOT.  I'm one of the age tranche that are permitted to
get vaccinated this week - except that demand outstrips
supply by 20x.  If I win the lottery to get the vaccine,
I must expose myself to all the other people gathering at
the convention center.  What's a paranoid to do?

I'll find some paranoid and devious way.  And I'll remain
paranoid, because our slow vaccine rollout will stimulate 
faster viral evolution.  This is war, only worse; the
enemy we must conquer is our lazy, ignorant selves.

The reason so many people don't understand epidemics (or 
tsunamis) is that these phenomena are blessedly rare and we
haven't evolved an innate sense of how to avoid them.  So,
we must rely on abstract mathematics, which almost nobody
is good at - just as few can perceive an immanent tsunami.

After this pandemic is behind us, the few who are educable
will be a slightly larger fraction of the population. 
Evolution in action, as my elitist friend Jerry Pournelle
used to say.  We can only hope that the educated will get
better at explaining to others, or there may not be enough
adults left to take care of the more-immune children.

Keith

-- 
Keith Lofstrom          keithl at keithl.com