The document discusses coronavirus and COVID-19. It describes COVID-19 as a positive-sense single stranded RNA virus that was first discovered in Wuhan, China. The virus spreads primarily through respiratory droplets from infected individuals. Older individuals and those with underlying medical conditions are at higher risk of severe disease. Signs and symptoms range from mild to severe and include fever, cough and shortness of breath. There are no specific treatments, so care is supportive through measures like fluids, oxygen and monitoring affected organs. Prevention focuses on hand washing, social distancing and disinfecting surfaces.

1. Coronaviridae Family
Only one genus Coronavirus has been
recognized.
Toroviruses, which cause gastroenteritis,
form adistinct genus.

2. Coronavirus
About covid -19 virus
Covid 19 virus or severe acute respiratory
syndrome cronavirus 2 SARS_CSARS_CoV 2 or 2019
novel coronavirus (2019_ N CoV) it's positive-sense
single stranded RNA virus
Because the strain was first discovered in Wuhan,
China it is has sometimes been referred to as
"Wuhan virus " or Wuhan coronavirus, genome
size 29,903 bases,

3. each SARS-CoV-2 virion is approximately 50_200
nanometers in diameter, Like other coronaviruses
(SARS-CoV-2) has four structural proteins known
as S spike ,E envelopes ,M membranes, and N
nucleocapsid
Protein N holds the RNA genome, and the S, E,
M proteins together creates the vital envelope.

4. Covid 19 transmission
_ It spreads primarily through contact with
infected person when they cough or sneeze, or
through droplets of saliva or discharge from the
nose.
The virus that cause covid 19 infects people of all
ages, however, evidence to date suggest that two
group of people are at higher risk of getting sever
covid19 disease.

5. These are older people (that is people over 60
years old) and those wih underlying medical
conditions ( such as cardiovascular disease,
diabetes, chronic respiratory disease, cancer).
It may be may be possible that a person can
get Covid 19 by touching a surface or object
that has the virus on it and then touching their
own mouth, nose or possible their eyes, but
this is not thought to be the the main way the
virus spreads

6. _people are thought to be most contagious
when they are most symptomatic
The virus is thought to have an animal origin,
through spillover infection
Signs and symptoms
Those infected with the virus may either be
asymptomatic or develop flu-like symptoms
and that include fever, cough and shortness
of breath.

7. _ diarrhea and upper respiratory
symptoms such as sneezing, runny nose,
or sore throat are less common
_ the incubation period ranges from 2 to 14
days, with an estimated median incubation
period of 5 to 6 days , the median time
from onset to clinical recovery for mild case
is approximately 2 weeks and is 3-6 weeks
for people with severe or critical disease.

8. This 3 main paths that the disease might take.
_ first ,it might be mild disease that resemble
other common upper respiratory diseases
_ the second path leads to pneumonia, that is
infection of the lower respiratory system
_ the third path , the most sever is rapid
progression to acute respiratory distress
syndrome.

9. _ elevated levels of blood interleukin-6 ,
high - sensitivity cardiac troponin I , lactate
dehydrogenase and lymphopenia are
associated with more severe disease.
Complication of covid 19 are sepsis and
cardiac complications
Lab diagnosis
Two main methods
1- molecular recognition and
2- serology testing

10. The center of disease control ( CDC) in particular
has developed a real- time revese - transcription
polymerase chain reaction for diagnostic purposes.
Prevention
Stop the spread of germs help prevent the
spread of respiratory disease like covid 19
1- avoid close contact with people who are sick
2- cover your cough or sneeze with a tissue, then
throw the tissue in the trash.

11. 3- clean and disinfect frequently touched
objects and surfaces
4- avoid touching your eyes, nose , and mouth
5- wash your hand often with soap and water for
at least 20 second
6- stay home when you are sick except to get
medical care.

12. Management
There are no specific antiviral medications.
People are managed with supportive care such as
fluid and oxygen support , while at the same time ,
they is monitoring and supporting other affected
viral organs.
Steroids such as methyl prednisolone are not
recommended unless the disease is complicated
by acute respiratory distress syndrome.