COVID-19 Clinical Aspects.
COVID-19 or the infection
caused by SARS-Coronavirus II,
typically has an incubation
period of 2 to 14 days,
on average 4 to 5 days most infections.
In fact, 80% of infections
are mild or even asymptomatic,
however, 15% of infections are
severe requiring hospitalization
and some form of oxygen delivery.
5% percent of these infections
however, are critical,
so, after initial hospitalization
these patients rapidly are transferred
to the intensive care unit and
require some form of ventilation,
whether it's invasive or non-invasive.
The clinical presentation and symptom
profile can vary with each virus variant
and the general immune status
of the population in general.
have generally been increasingly mild
as the immunity of the general
population has increased.
Typical common symptoms, are fevers,
anywhere from 100 degrees Fahrenheit
or 37.7 Celsius and higher,
accompanied by a dry non-productive cough
and typical flu-like symptoms,
so, malaise, myalgias, anorexia, et cetera.
Those cases that go on to be more severe, however,
rapidly progress to develop dyspnea,
so, difficulty breathing,
along with shortness of breath,
chest pain, hemoptysis, on exam
they may have fine crackles
and they certainly will have evidence
of respiratory insufficiency.
Complications after one has even
mild but many times severe COVID-19,
can include a whole list as you see here.
Anywhere from pneumonia and acute
respiratory distress syndrome,
to cardiac injury with
deconditioning especially in athletes
and dysrhythmias, septic shock, liver dysfunction,
multi-organ failure, including
acute kidney injury specifically
and then a higher risk than normal
of venous and arterial thrombosis.
Asymptomatic cases are fortunate I guess,
because they don't develop
any noticeable symptoms,
although they may still yet go on to
develop anosmia, hyposmia and dysgeusia,
so, abnormalities in their
ability to taste and smell.
Unfortunately, even while asymptomatic,
they can just as easily transmit
the virus as anybody else.
Asymptomatic cases are anywhere
from 17% to 50% of all cases,
the challenge of course is that one
doesn't know what one doesn't know.
So, there may be far more
asymptomatic cases out there,
that have not presented to medical attention
and therefore, have not been identified through,
antibody or molecular diagnostic modalities.
What is known, for those asymptomatic
cases that have been confirmed,
is that their transmission rate is at least 42%,
so, these represent a significant challenge
to epidemic and pandemic control,
because they don't know that
they're sick potentially
and therefore, can be contagious.
However, if they do happen
to come to medical attention,
many times for some other reason,
they may yet still show radiologic
and laboratory findings,
typically seen with COVID-19,
patients who have typical symptoms.
The mild cases, so again these are
80% of all the symptomatic cases,
will have that same dry not productive cough,
moderate fever and the
abnormalities and taste and smell,
along with flu-like symptoms,
sometimes, they also will have
especially, loose stools or
non-bloody diarrhea, nausea
and vomiting, abdominal pain
which is non-specific and crampy,
they may go on to develop a productive cough,
along with headache the significant myalgias
and arthralgias so muscle joint pain
and then non-specific rashes.
Severe disease, the 15% of symptomatic cases,
in addition to the initial
presentation as seen with mild illness,
will go on to develop dyspnea, hypoxia
and potentially significant
abnormalities on chest radiography,
where over half of their lung fields,
are whited out are involved
with inflammatory disease.
These patients, also will
likely have higher fevers,
along with chest pain
hemoptysis, significant anorexia,
even including weight loss.
Then the 5% of symptomatic cases
that go on to have critical disease,
these are the ones who will develop
some degree of respiratory failure,
which may start as hypoxia,
requiring oxygen delivery
and then difficulty maintaining
ventilation and perfusion
and requiring some form of ventilation.
They also may show evidence of sepsis,
including pneumonia, cardiomyopathy,
acute respiratory distress syndrome,
acute kidney injury, certainly thrombosis.
Recovery time for the mild cases,
is anywhere from a couple days to two weeks,
depending on how many symptoms
they initially present with.
However, recovery time for
severe and critical disease,
is three to six weeks and in fact those
who are in an intensive care unit,
with critical disease may well be,
in hospital for six weeks or longer.
Symptoms and signs even with mild COVID-19,
can last anywhere from the
several weeks of recovery,
from the acute process to three
months or even months to years,
with what is now known as long COVID
syndrome or post COVID syndrome.
A post-COVID-19 condition is defined
by the World Health Organization
as one that occurs three months
from the onset of COVID 19 with symptoms
that lasts for at least two months
and cannot be explained
by an alternative diagnosis.
In general, these post-COVID symptoms
are less commonly experience
in vaccinated individuals.
Some of these symptoms may
be specific to COVID-19,
but many others are very typical as
you might see with other viruses,
especially and including
fatigue, myalgias et cetera.
If you look at a chart as this
one, for post COVID-19 symptoms,
you can see that a majority of
these last from weeks to months
and in many cases, months to even longer.
So, reduction in quality of life,
sort of a non-specific marker of,
“I don't feel well, but I feel less
well than I did before I got sick.”
Well over half of COVID-19 survivors
report this this perception,
for at least three months or longer.
Fatigue up to 87% comment on
fatigue for over three months,
dyspnea, the challenge with
shortness of breathing,
especially noted with
exercise or even just walking,
much less walking upstairs up
to 71% will report this finding,
for two to three months.
Chest discomfort, so that sort
of non-specific, chest tightness
or shortness of breath up to
44% will report this for again,
two to three months.
Some form of cough, anywhere from weeks to months,
anxiety, depression, impaired
memory, the cognition effects,
especially the concentration
effects, poor concentration,
with post COVID-19 survivors can be
quite dramatic and of a huge concern.
Fortunately, fewer percentages
of people report these,
but again, they last for weeks to months.
The anosmia, dysgeusia complaints, so
alterations of sense of smell and taste,
will last anywhere from month,
to some people up to six months or so.
And then a combination of findings, sort of,
the long COVID syndrome,
which you see listed there,
so joint pain headaches, sicca syndrome, rhinitis,
dysgeusia, poor appetite, all these things.
These can be seen in 16% of individuals,
as a specific long COVID syndrome,
lasting at least months and in some individuals,
anecdotally a year or more.
And because those individuals,
who were very sick with COVID-19,
or even mildly sick and yet
had alterations in their job,
perhaps, they lost their job
they lost their home et cetera,
they're likely to have
post-traumatic stress disorder,
10% to even higher will have PTSD,
lasting for at least a month.