Lec 22 - Respiratory viral infections 2: Coronaviruses

Question 1

Describe the 3 host determinants and whether they affect the individual or the population.

Answer 1

1. Contagiousness (individual) = tropism, disease presentation, lung function, pre-existing immunity
2. Susceptibility (individual) = receptors and glycosylation, pre-existing immunity, lung anatomy
3. Transmission (population) = social contacts, age-related mixing patterns

Question 2

What is the classification and transmission of Influenza viruses A-C? What does each type infect?

Answer 2

• Orthomyxoviridae; group 5 (-) ssRNA segmented
• Aerosols causing URT and LRT infections
• A and B infect humans, C infects animals

Question 3

List the symptoms and complications of Influenza virus infection.

Answer 3

• Symptoms = aches, fever, headache, confusion, cough, sore throat, nasal congestion, nausea, fatigue
• Complications = Guillain Barre syndrome (neurological), febrile convulsions, myocarditis, sinusitis, bronchitis, prenatal mortality and prematurity

Question 4

What is the classification of human coronaviruses? Which are high or low pathogenicity?

Answer 4

• Alpha and betacoronaviruses of Coronaviridae; group 4 (+) ssRNA
• High = SARS-CoV 1 and 2 and MERS-CoV
• Low = alphaCoV 229E and NL63; betaCoV HKUI and OC43

Question 5

What are the symptoms and complications of human coronaviruses?

Answer 5

• Symptoms = seasonal common cold, otitis media, atopic, bronchiolitis, croup, pneumonia
• Complications = neurological, fatal

Question 6

What does SARS-CoV-1 infect and how is it transmitted? Where did it originate from?

Answer 6

• Infects = LRT, GI tract
• Transmission = droplets, close contact
• Chinese wet markets = wild game with virus

Question 7

What are the symptoms of SARS-CoV-1 and how was it controlled? Why was it easy to control?

Answer 7

• Symptoms = fever, malaise, coagulopathy, pneumonitis
• Controlled by traditional public health measures and healthcare facilities
• Transmittable when symptomatic so easily detected

Question 8

What type of coronavirus is MERS-CoV, where did it originate from and how was it transmitted? List some symptoms.

Answer 8

• Betacoronavirus from Saudi Arabia in 2012
• Transmission = in/direct contact with dromedary camels
• Asymptomatic, fever, cough, shortness of breath, pneumonia, GI symptoms, death

Question 9

Describe the pathology of COVID-19 from SARS-CoV-2 infection.

Answer 9

• Primary viraemia in lung pneumocytes then secondary viraemia in blood and dissemination
• Brain stem damage = cardiac and respiratory impairment
• Damaged alveoli and pneumocyte = inflammation and alveolar bleeding blocking airways
• Low oxygen levels in blood

Question 10

List the symptoms of SARS-CoV-2.

Answer 10

Loss of taste and smell, muscle pain, fatigue, acute respiratory disease symptoms

Question 11

What is the classification and other names of Hantavirus pulmonary syndrome?

Answer 11

• Hantavirus of Bunyaviridae; enveloped segmented (-) ssRNA genome
• Four Corners Disease, Sin Nombre virus