Coronaviruses

Question 1

In which family does coronavirus belong?

Answer 1

coronaviridae family

Question 2

List the 7 classes of coronaviruses

Answer 2

Human coronavirus 229E
Human coronavirus OC43
Human coronavirus NL63
Human coronavirus HKU1
Severe acute respiratory syndrome coronavirus (SARS – CoV-1))
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
Middle East respiratory syndrome coronavirus (MERS CoV)

Question 3

What type of virus is a coronavirus?

Answer 3

ssRNA virus

Question 4

Explain the pathogenesis of coronavirus infection

Answer 4

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

Question 5

describe the coronavirus clinical picture

Answer 5

Common cold –rhinitis, sore throat, coughing
* Patients with underlying lung disease may have more severe infection
* Infants may have tracheolaryngobronchitis (croup), bronchitis or pneumonia

Question 6

How is Coronavirus diagnosed?

Answer 6

Multiplex PCR panels (with coronavirus subtypes) available

Question 7

How did SARS-CoV 1 and 2 cause infection in humans?

Answer 7

ARS CoV-1 and (SARS CoV-2)emerged as causes of infection in humans(and person person spread) due to changes in the viral reservoirs and changes in human eating habits

Question 8

How long does SARS-CoV survive outside the body?

Answer 8

2 days on surfaces, 4 days in faeces

Question 9

how long is the incubation period?

Answer 9

Incubation period: 4-6 days(range 1-14 days) and patients infectious during symptomatic period (most
infectious during week 2 of illness)

Question 10

Which receptor does sars-cov-2 bind to?

Answer 10

Angiotensin - converting enzyme 2

Question 11

Once sars-cov 2 binds to ACE 2, what happens?

Answer 11

Once bound, the 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 12

clinical picture for SARS-COV 2 infection

Answer 12

First phase of illness: 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)

Question 13

Treatment of SARS CoV 2

Answer 13

Supportive treatment (eg. ventilation)
*. Ribavirin,chloroquine and interferon, lopinavir/ritonavir combination (protease inhibitors), SARS –specific Ig
* Corticosteroids damped down the effect of virally induced cytokine responses that could
result in damage of lung tissue

Question 14

Structure and genus of sars-cov 2

Answer 14

Enveloped, positive sense RNA virus (like all other coronaviruses)
* Genus: Betacoronavirus (same as SARS- CoV-1 and MERS-CoV)

Question 15

Which variant causes more severe disease?

Answer 15

Delta varient

Question 16

Which variant has highest replication advantage and high transmissibility?

Answer 16

Omicron