What
the
medical
profession
is
seeing
today
has
not
been
witnessed
in
over
a
century.
A
viral
infection
that
is
extremely
difficult
to
treat
spread
rapidly
and
has
now
become
a
pandemic.
It
emerged
from
China
a
few
months
ago
to
cripple
the
whole
world
today.
The
last
time
such
an
endemic
occurred
was
in
1918 when the Spanish Flu killed over 25 million people.
Viruses:
Viruses
cause
a
variety
of
infection
from
a
simple
cold
to
the
deadly
Ebola
infection.
Most
of
the
serious
diseases
caused
by
them
have
now
been
conquered
through
suitable
vaccines.
However
every
now
and
again
a
new
form
evolves.
Most
of
these
are
tackled
effectively
by
the
body’s
own
immune
system.
Unfortunately
a
deadly
form
evolves
from
time
to
time
when
the
body’s
immune
system
is
unable
to
fight
it.
The
new
Corona Virus that causes “Covid 19” infection is one such. It is a respiratory virus.
How is the “New Corona Virus” different
We
have
known
about
Corona
Viruses
for
more
than
50
years.
So
why
are
we
panicking
about
this
new
virus.
By
exposure
to
many
types
of
corona
viruses
in
the
past,
our
body’s
defence
mechanism
has
acquired
suitable
antibodies
to
fight
an
invading
virus
that
is
similar
to
the
ones
that
it
has
encountered
before.
The
New
Corona
Virus
on
the
other
hand
is
completely
different
to
the
ones
that
the
body
has
been
exposed
to
before.
Therefore
it
does
not
have
a
ready
antibody
to
fight
the
newcomer.
The
immune
system
has
to
generate
a
new
antibody
to
fight
the
virus
and
that
may
take
a
few
days.
In
addition
to
that
the
binding
capacity
(fusion)
of
the
new
corona
virus
to
human
cells
appears
to
be
more
than
100
times
stronger
than
those
of
any
previously
known corona viruses.
Effect of the virus when it enters the human body:
The
virus
is
so
named
because
it’s
surface
is
covered
by
bulbous
projections
that
look
like
a
crown
when
viewed
by
an
electron
microscope.
It
is
0.125
micron
in
diameter
(human
hair
is
100
microns).
The
surface
projections
are
made
up
of
protein
that
contains
the
infective
material
(the
virion).
When
an
infective
droplet
is
inhaled,
the
virus
can
reach
any
area
from
the
throat
to
the
lung
parenchyma
(the
alveolus).
For
the
virus
to
multiply
and
infect
the
individual it must first enter the living cell.
The
glycoprotein
spikes
on
the
virus
fuse
to
a
suitable
host
cell
and
inject
the
infective
material
in
to
the
cell.
An
enzyme
called
ACE2
which
is
present
on
certain
cell
membranes
like
the
lungs,
arteries,
kidneys
and
intestines
facilitates
the
spikes
to
fuse
with
the
cell.
Once
inside
the
host
cell
they
start
replicating.
The
genetic
material
of
the
virus
then
makes
the
cell
produce
several
copies
of
the
virus.
The
new
copy
can
then
enter
an
adjacent
cell
and
repeat
the process. Thus within a short time the virus starts spreading.
Symptoms
of
someone
infected
with
the
virus
may
vary
from
dry
cough,
fever
or
difficulty
in
breathing.
Some
may
even
complain
of
loss
of
taste
or
smell.
If
the
individual
is
young
and
healthy
it
may
cause
only
mild
symptoms
affecting
the
upper
respiratory
tract
giving
rise
to
fever
or
bouts
of
coughing.
However
if
they
have
other
co-existing
conditions
like
high
blood
pressure,
diabetes,
chronic
respiratory
disease,
obesity
or
if
their
immunity
is
compromised
as
when
receiving
treatment
for
cancer
etc.
the
person
may
develop
a
more
serious
form
of
the
disease
affecting
the
lung.
Older
generation
are
also
prone
to
develop
a
more serious form of the disease.
When
the
lungs
are
affected,
the
lining
membrane
of
the
alveoli
becomes
inflammed
giving
rise
to
pneumonia.
This
results
in
the
alveoli
becoming
filled
with
fluid
and
inflammatory
cells.
This
affects
the
exchange
of
gases
in
the
lung
causing
reduced
amount
of
oxygen
being
carried
in
the
blood.
When
the
disease
progresses
further,
more
of
the
lung
is
affected.
When
the
oxygen
level
in
the blood drops below a critical level all the major organs can start to fail leading to death.
Diagnostic tests for COVID 19:
(fall into two broad categories)
1
.
Swab
Test:
Molecular
tests
or
Nucleic
acid
test
of
secretions
from
the
nose
and
throat
will
detect
the
virus’
genetic
code.
2
.
Blood Test: Immunoassay will detect proteins (antigens or antibodies) associated with the virus.
Nucleic
acid-based
tests
are
the
most
sensitive
for
early
detection
of
infection.
The
test
is
called
real
time
reverse
transcription–polymerase
chain
reaction
(
real
time
RT-PCR
).
It
is
one
of
the
most
accurate
laboratory
methods
for
detecting,
tracking,
and
studying
the
corona
virus.
A
swab
from
an
individual
will
collect
mucous,
saliva,
bits
of
cells
and
with
it
viral
RNA
if
it
is
present.
The
sample
is
then
processed
in
the
lab.
Results
are
usually
available
within
a
few
hours.
Newer
machines
that
can
give you the result in under an hour are being developed and will soon be available on the market.
Immunoassay:
Usually
blood,
plasma,
or
serum
is
used
for
the
test.
Immunoassay
detects
the
presence
of
specific
immune
proteins.
The
tests
check
for
antigen
or
antibody
in
the
specimen.
Antigens
are
from
the
virus
and
antibodies
are
from
the
patients
immune
system.
The
tests
use
both
virus
specific
antigen
or
antibody
for
the
immunoassay.
During
the
early
stage
of
infection
the
viral
antigens
circulating
in
the
blood
will
react
with
the
antibody
used
in
the
test
to
indicate
that
the
patient
is
infected.
This
is
the
basis
for
many
of
the
“Rapid
Antibody
Tests”.
A
few
days
after
an
infection
the
patient
is
likely
to
produce
antibodies. These antibodies will react with viral specific antigen to indicate the presence of ongoing or past viral infection.
At
the
moment
Immunoassay
aren’t
as
sensitive
as
nucleic
acid
tests
to
detect
infection
during
the
early
stages.
However
they
are
easier
to
use
and
would
indicate
that
the
individual
became
infected
or
was
exposed
to
the
infection
a
few
days
(or
weeks)
before
the test. The test will be very useful for surveillance rather than for diagnosis.
Corona
viruses
are
the
common
cause
of
colds
and
other
upper
respiratory
infections
everywhere.
Novel
Corona
Virus
(the
new
corona
virus)
is
an
altered
form
of
the
same
virus
that
can
cause
a
serious
disease
that
could
turn
fatal.
So
how
do
we
know
that
the
cold
or
cough
that
you
have
developed
is
not
the
usual
ordinary
cold
or
cough.
Unless
you
are
tested
you
may
not
know.
The
general
advice
now
is,
start
treating
any
cold
or
cough
with
simple
medication.
As
a
precaution
isolate
yourself
from
the
rest
of
the
family,
as
you
may
still
be
infected
with
mild
symptoms.
Most
people
have
only
mild
illness
and
usually
recover
at
home
without
medical
care.
As
the
incubation
period
for
the
virus
can
be
up
to
14
days,
isolation
should
be
for
14
days.
However
if
you
develop a high fever, have difficulty controlling your cough or have difficulty breathing, you must request urgent medical help.
If
you
are
over
70
or
have
other
co-morbid
conditions
like
hypertension,
diabetes,
asthma,
obesity
or
chronic
heart
disease
you
have
to
be
extra
careful
and
call
for
medical
advice
if
any
of
the
above
mentioned
symptoms
are
getting
worse..
Do
not
wait
until
you have difficulty breathing.
Treatment:
Most
people
who
get
infected
will
recover
well
at
home.
All
that
is
necessary
is
to
isolate
yourself
from
other
family
members
and
treat
the
infection
as
you
would
for
a
flu
or
cold.
As
of
now
there
is
no
specific
drug
that
will
cure
the
disease.
Paracetamol
(acetaminophen) (max 3000 milligrams) can be prescribed for the pain and fever that may accompany the disease.
Hydroxychloroquine
and
chloroquine
have
been
shown
to
inhibit
the
virus
from
entering
the
cell.
It
has
also
been
reported
that
it
would
kill
the
virus
within
the
cell.
However
it
does
not
help
everyone
and
also
they
have
other
side
effects
on
the
heart
etc
and
therefore not suitable for everyone.
Until
the
scientists
come
up
with
a
definite
drug
to
cure
the
disease
the
main
management
now
is
to
make
sure
the
patient
is
comfortable,
well
hydrated,
on
a
good
diet
and
well
oxygenated.
Antibiotics
are
necessary
only
when
they
develop
secondary
bacterial infection following pneumonia.
Hospital Treatment:
According
to
WHO
80%
of
patients
who
have
tested
positive
recover
without
the
need
to
go
in
to
hospital.
However
for
the
remaining
20%
when
symptoms
get
worse
and
breathing
becomes
difficult,
they
should
be
shifted
to
the
hospital.
Difficulty
to
breathe often indicates that the pneumonia is getting worse and oxygen level in the blood is dropping.
Treatment
in
the
hospital
will
consist
mainly
of
isolating
the
patient
with
intensive
support
and
administration
of
oxygen
when
necessary
through
the
best
possible
means.
Suitable
antibiotics
will
be
given
to
counter
secondary
bacterial
infection
when
needed.
Take Home Points:
•
Covid 19 is a very virulent virus that spreads easily
•
At the moment there is no curative medicine available to treat the infection
•
Several vaccines are now being offered for the infection
•
Although the vaccine may not prevent an infection you are unlikely to suffer the disease
•
Avoid infection by staying away from crowds even after vaccination
•
Wear a mask to prevent spread when you are out and about
•
Maintain a safe distance from others in a public place
•
If infection is suspected in a member of family, keep them isolated for 2 weeks
•
Wash your hands with soap and water regularly (prevents transmission of infection
This Topic is discussed in greater detail in the “Forum” under
1. Covid 19 infection; 2. Corona Virus Part I; 3. Corona Virus Part II
Covid 19 Infection
K. Badrinath, FRCS