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Tuesday, March 17, 2020

Epidemics are not "exponential growth” forever -- climate change may help !


IS  THERE  A  COVID-19 
CLIMATE  CHANGE  
CONNECTION ?

COVID-19,
aka "Wuhan Flu",
may be sensitive 
to temperature 
and humidity, 
like many of the 
more common 
strains of flu are.

Early virus hotspots 
were Wuhan (China), 
Daegu (South Korea) 
and Qom (Iran). 

( Note that  the actual 
virus is SARS-CoV-2 )

All three locations 
are in a narrow 
latitude band 
( 30N-35N ), 
and all have 
similar climates. 

A lot of Chinese
citizens vacation
in warmer Thailand
... but Thailand 
did not become a
COVID-19 hot spot.

Maybe climate change,
such as warming of the
Northern Hemisphere, 
as we approach 
the summer, 
will be helpful ?



There is also 
an unusual age effect,
with people under 40
resisting the virus.

Italy, Spain. and Japan 
have high median ages,
so are more susceptible.




FLU  HITS  EVERY  YEAR
In the U.S., during
the colder months,
1,000 deaths a week
from all strains of the 
flu, is not unusual.

In comparison,
COVID-19 
has killed
fewer than 
100 Americans,
as of today, 
March 17, 2020.

And the very
unprecedented
"social distancing" 
actions will slow 
the spread.

I'm hoping
that in a few 
months, people
here in the U.S.
will look back, 
and feel that
governments
over reacted !



2009  H1N1  SWINE  FLU
There had been
a serious bout of the 
H1N1 "Swine Flu"
in 2009. 

I didn't even 
remember it
until recently.

According to 
CDC estimates, 
global deaths
from H1N1 flu
were between 
about 8,870 
and 18,300,
between 
April 2009 
and April 2010.

Other estimates
were higher,
or much higher!

These are 
more data 
to compare
with COVID-19.



CORONAVIRUSES
There are many 
different kinds 
of coronaviruses. 

Most cause colds, 
or other mild 
respiratory 
( nose, throat, lung ) 
illnesses. 

There have been 
far more deadly 
coronaviruses
in the past:

(1)
Severe Acute 
Respiratory 
Syndrome
  ( SARS ),
      and 

(2)
Middle East 
Respiratory 
Syndrome 
   ( MERS ).

Coronaviruses 
are named because 
they appear different 
under a microscope. 

They appear
to be covered with 
pointed structures 
that surround them 
like a corona, 
or crown.

SARS was first 
discovered in Asia, 
in February 2003. 

The SARS outbreak 
lasted six months.

SARS spread 
to more than 
two dozen countries 
in North America, 
South America, 
Europe, and Asia, 
before being stopped 
in July 2003.



In September 2012, 
the World Health 
Organization 
was notified of 2,494 
laboratory-confirmed 
cases of MERS 
in the Middle East. 

The fatality rate 
was a very high 
34.4% !

ERS had subsided 
by June 2013. 

In 2015, there was 
a second 
MERS outbreak 
in South Korea,
with 186 cases, 
and 38 deaths.




COVID-19
spreads easier 
than SARS or MERS, 
but is far less deadly.




EXPONENTIAL  GROWTH ?
Real exponential 
growth never stops.

That’s NOT 
what happens 
with a disease
such as 
COVID-19.

The growth of the 
total number of 
COVID-19 cases 
in South Korea 
and China is now
leveling off.
( China’s numbers 
are questionable,
but South Korea's 
can be trusted ).













There's an 
“s-shaped” curve,
slanting to the right, 
which is called a 
“Gompertz Curve”:
y(t) = α * exp(-β * exp(-k^t)
             t = time
    alpha = upper asymptote
       beta = growth displacement
             k = growth rate

A Gompertz Curve 
ends up at a 
maximum value 
that it does not
exceed.

"Social distancing"
can significantly
flatten the curve.











It appears that 
flu deaths in China 
and South Korea 
are nearing 
such a peak.




What works for 
all flu viruses,
and this advice 
is not new:

(1)
wash hands and
fingers thoroughly, 

(2)
social distancing, 

(3)
avoid large gatherings, 

(4)
self-quarantine
if you have symptoms.




COVID-19  IN  CHINA
China's current 
population
is more than 
1,437,000,000, 
based on the latest 
United Nations data.
      
Total 2018
China mortality, 
from all causes,
was 7.121 deaths 
per 1000 people, 
or 28,035 deaths 
per day.

The total 
COVID-19 
deaths were
reported as
about 3,200 
over the past 
two months,
or an average of 
50 deaths per day.

Averaging 50 
COVID-19 
deaths per day, 
adds only +0.18% 
to a "normal"
death total of 
28,035 per day.



Hysteria and stress
about COVID-19 
are counterproductive.

That advice
applies to 
global warming 
hysteria too.