Coronaviruses are a
large family of viruses
that usually cause
mild to moderate
upper-respiratory
tract illnesses.
Structure And Genetics:
Coronaviruses, so named because they look like
Crown/ Halos (known as coronas)
Large family of enveloped RNA viruses,
characterized by club-like spikes that project
from their surface.
Single strand of RNA,28-32 kilobases long.
Mutate and change at a high rate, which can
create havoc for both diagnostic detection as
well as therapy (and vaccine) regimens.
Belong to Nidovirales order and family
Coronaviridae ( Arteriviridae, and
Roniviridae), and subfamily Coronavirinae
Coronaviruses are zoonotic.
Three of the coronaviruses had more serious
outcomes in people
oSARS emerged in late 2002 and disappeared by
2004
oMERS emerged in 2012 and remains in
circulation in camels
o2019-nCoV (SARS-CoV-2) emerged in
December 2019 from China and a global effort is
under way to contain its spread.
How SARS- CoV- spread?
oSpread from person-to-person
ovia respiratory droplets produced when
an infected person coughs or sneezes
oInhaled into the lungs.
PATHOGENESIS(PROPOSED)
The virus might pass through the mucous
membranes, especially nasal and larynx mucosa,
then enters the lungs through the respiratory
tract.
The early most common symptoms of infection
are fever and cough .
The virus may enter the peripheral blood from
the lungs, causing viremia.
Then the virus would attack the targeting organs
that express ACE2, such as the lungs, heart,
renal, gastro-intestinal tract .
PATHOGENESIS(CONT….)
The median time from symptom onset to ARDS is
about 8 days .
It is speculated that in this way, the virus begins
a second attack, causing the patient’s condition to
aggravate around 7–14 days after onset.
During early stage of the disease WBCs count is
normal or slightly low, and lymphopenia is
observed in patients.
B lymphocyte reduction may occur early in the
disease, which may affect antibody production in
the patient.PATHOGENESIS(CONT….)
In severe type patients, lymphocytes were
significantly reduced .
Lymphocytes may decrease as the disease
progress (Mechanism Unknown).
The inflammatory factors IL-6 increase
significantly . Aggravate disease around 7–14
days after onset.
Non-survivors had higher levels of neutrophils,
D-Dimer, blood urea nitrogen, and creatinine
than the survivors.
SYMPTOMS:
Common signs of infection include respiratory
symptoms,
fever,
cough,
shortness of breath and breathing
difficulties.
In more severe cases, infection can cause
pneumonia, severe acute respiratory
syndrome, kidney failure.
TESTING:
CDC has developed a new laboratory test kit for
use in testing patient specimens for 2019 novel
coronavirus (2019-nCoV). The test kit is called
the “Centers for Disease Control and Prevention
(CDC) 2019-Novel Coronavirus (2019-nCoV)
Real-Time Reverse Transcriptase (RT)-PCR
Diagnostic Panel.”
It is intended for use with the Applied
Biosystems 7500 Fast DX Real-Time PCR
Instrument with SDS 1.4 software. This test is
intended for use with upper and lower
respiratory specimens.
PREVENTIONS:
There is currently no vaccine to prevent 2019-
nCoV infection. The best way to prevent infection
is to avoid being exposed to this virus:
Wash your hands often with soap and water for
at least 20 seconds, especially after going to the
bathroom; before eating; and after blowing your
nose, coughing, or sneezing.
If soap and water are not readily available, use
an alcohol-based hand sanitizer with at
least 60% alcohol. Always wash hands with
soap and water if hands are visibly dirty.
Avoid touching your eyes, nose, and mouth
with unwashed hands.
Avoid close contact with people who are sick.
Stay home when you are sick.
Cover your cough or sneeze with a tissue, then
throw the tissue in the trash.
Clean and disinfect frequently touched
objects and surfaces using a regular household
cleaning spray or wipe.
Use facemask especially at closed spaces to avoid
contracting contaminated air droplets.