Coronavirus

Question 1

Classification of corona virus

Answer 1

Human coronavirus 229E
Human coronavirus OC43
Human coronavirus NL63
Human coronavirus HKU1
Severe acute respiratory syndrome coronavirus (SARA 1 AND 2).

Question 2

PathogenesiS OF virus

Answer 2

Virus enters respiratory tract and replicate in epithelial cells of upper respiratory
tract. * Spread to lower respiratory tract occurs

Question 3

what do corona virus cause ?

Answer 3

Common cold – rhinitis, sore throat, coughing

• Infants may have tracheolaryngobronchitis (croup), bronchitis or pneumonia

Question 4

Diagnosis, treatment and prevention of corona virus

Answer 4

Diagnosis-Seldom required due to mild and passing nature of illness

treatment- Multiplex PCR panels (with coronavirus subtypes) available * Symptomatic and supportive treatment

prevention-General hygiene and disinfection. No vaccine available

Question 5

Severe acute respiratory CoV (SARS CoV-1)

Answer 5

was identified in cell culture with electron microscopy and molecular
methods
* SARS-CoV-1 entered human population from animal source

then spreaded from person to person

Question 6

how do SARS-COV 1 spread

Answer 6

they via respiratory droplet and contact with contaminated surface fomites

Question 7

where do the virus replicate?

Answer 7

Virus replicates in lower respiratory tract and both viral factors and immune and cytokine dysregulation play a role in pathogenesis

Question 8

SARS Co-V receptor on host cells that bind
viral spike (S) protein

Answer 8

angiotensin converting enzyme 2 ACE

Question 9

Once the virus is bound to ACE 2 what happens

Answer 9

ACE2 receptor is down-regulated. This results in lung injury due to
overproduction of angiotensin 2 stimulating the receptor and causing increased blood
vessel permeability and respiratory distress.

Question 10

First phase symptoms of a person with corona virus?

Answer 10

: fever > 38 C, rigors, myalgia, sore throat and GIT symptoms
(diarrhoea) * After 3-7 days: cough and shortness of breath (SOB) * Hypoxia may develop (10-20% of patients require ventilation) * Relative lymphopenia or neutropenia
* Some patients’ illness have a biphasic nature (apparent recovery followed by
clinical worsening) * Mortality highest in the elderly and in patients with co-existing illness

Question 11

Treatment and prevention

Answer 11

Other treatment modalities showed some benefit e.g. Ribavirin, chloroquine and
interferon, lopinavir/ritonavir combination (protease inhibitors

corticosteroids

Question 12

the novel corona virus was identified as?

Answer 12

the cause of cluster of pneumonia.

Question 13

genus of virus

Answer 13

Beta coronavirus sa me as SARS- cov 1 and MERS- cov

Question 14

Omicron variant and sublineages

Answer 14

devolved as result of mutation of S protein.
BA 1, BA 2, BA 4, BA 5 and other (BQ 1, BQ11, BF7,BA. 2.75, XBB, XBB.1, XBB 1.5.

Question 15

Period of infectiousness and viral shedding

Answer 15

• Period of infectiousness: Viral load peaks 2 days before to 1 day after onset of
  symptoms. Non- infectious: 7 – 10 days after onset of symptom

Question 16

Viral load shedding

Answer 16

may increase with age and severity

Question 17

Immune responses after infection

Answer 17

Protective SARS-CoV-2 Ab (humoral) and cellular immune responses induced after infection
* Humoral (antibody) responses
-Majority of patients develop neutralising Ab’s against S(spike) protein after infection and/or vaccination
-N (nucleocapsid) Ab may develop after natural infection (not after vaccination)
-Magnitude of Ab response may be associated with disease severity and patients with mild infection may
not mount a detectable Ab response
-Ab titers decline after several months but potential for long-term memory humoral response exists
* Cell-mediated immunity
-SARS- CoV-2 specific CD4 and CD8 T cell responses identified in patients who ha