Coronaviruses are large, enveloped RNA viruses responsible for common colds and severe respiratory illnesses like SARS. The document details their structure, replication process, and the symptoms and transmission of illnesses they cause, including potential treatments and control measures. Despite challenges in culturing human coronaviruses, ongoing efforts are in place to develop vaccines and treatments.

1. SUBMITTED BY
ANDREA TITUS
MD3

2. Coronaviruses are large, enveloped RNA viruses
The human coronaviruses cause common colds, may cause lower
respiratory tract infections, and have been implicated in gastroenteritis
in infants.
A novel coronavirus was identified as the cause of a worldwide
outbreak of a severe acute respiratory syndrome (SARS) in 2003
Animal coronaviruses cause diseases of economic importance in
domestic animals.
Coronaviruses of lower animals establish persistent infections in their
natural hosts.
The human viruses are difficult to culture and therefore are more
poorly characterized.

3. Human coronavirus OC43. Note the characteristic
large, widely spaced spikes that form a “corona”
around the virion

4.  Virion: Spherical, 120–160 nm in diameter, helical nucleocapsid
 genome: Single-stranded RNA, linear, non - segmented, positive-
sense,27–32 kb, capped and polyadenylated, infectious
 Proteins: Two glycoproteins and one phosphoprotein. Some viruses
contain a third glycoprotein (hemagglutinin esterase)
 envelope: Contains large, widely spaced, club- or petal-shaped spikes
 Replication: Cytoplasm; particles mature by budding into endoplasmic
reticulum and Golgi
 Outstanding characteristics:
 Cause colds and SARS
 Display high frequency of recombination
 Difficult to grow in cell culture

5. Human coronaviruses do not grow well in cell culture , details of viral
replication have come from studies with mouse hepatitis virus, which is
closely related to human strain OC43.
The replication cycle takes place in the cytoplasm of cells.
entry to the cell the virus particle is uncoated and the RNA genome is
deposited into the cytoplasm.
Coronavirus have single positive strand RNA genome, they can directly
produce their protein and new genome in the cytoplasm.
The Coronavirus genome has a 5’ methylated cap and a
3’polyadenylated tail. This allows the RNA to attach to ribosomes for
translation.

6. The protein N binds genomic RNA and the protein M is
integrated into the membrane of the endoplasmic
reticular(ER), protein S after binding, assembled nucleo-
capsids with helical twisted RNA budding into the ER
lumen and are encased with membrane.
These viral progeny are finally transported by Golgi
vesicles to the cell membrane and exocytosis.

7. Coronavirus replication cycle.

8. Coronaviruses primarily infect the upper respiratory and
gastrointestinal tract.
SARS coronavirus also infects epithelial cells lining salivary gland
ducts (shown in monkeys).
Coronavirus infections in humans usually, but not always, remain
limited to the upper respiratory tract.
SARS serious respiratory illness, including pneumonia and progressive
respiratory failure.
Virus can also be detected in other organs, including kidney, liver, and
small intestine , and in stool.

9. The SARS virus probably originated in a nonhuman host, most likely
bats, was amplified in palm civets, and was transmitted to humans in
live animal markets.
Coronaviruses are suspected of causing some gastroenteritis in humans

10. Produce “colds,” usually afebrile , in adults.
The symptoms are similar to those produced by rhinoviruses, typified
by nasal discharge and malaise.
Incubation period is from 2 to 5 days, and symptoms usually last about
1 week.
SARS coronavirus causes severe respiratory disease.
The incubation period averages about 6 days.
symptoms include fever, malaise, chills, headache, dizziness, cough,
and sore throat, followed a few days later by shortness of breath.

11. ELISA
PCR

12. no proven treatment for coronavirus infections and no
vaccine.
Protease inhibitors used in the treatment of human
immunodeficiency virus infections (eg, lopinavir) have in
vitro activity against SARS coronavirus.
SARS vaccines are under development

13. Control measures that were effective in stopping the
spread of SARS included isolation of patients, quarantine
of those who had been exposed, and travel restrictions.
Use of gloves, gowns, goggles, and respirators by health
care workers.

14.  THANK YOU