22 - Viral Respiratory Diseases 2

Question 1

Factors affecting host contagiousness at individual level

Answer 1

• Tissue and cellular tropism
• Symptom presentation (asymptomatic etc)
• Lung function
• Pre existing immunity

Question 2

Factors affecting host susceptibility to infection at individual level

Answer 2

• Tissue specific receptor expression
• Pre existing immunity
• Lung anatomy

Question 3

Factors affecting transmission at population level

Answer 3

• Social contact patterns
• Age related mixing patterns

Question 4

Influenza virus

Answer 4

• A. B, and C belong to Orthromyxovirdiae family
• (-)ssRNA, segmented, undergo reassortment
• Transmitted by aerosols
• Cause URT and LRT infections
• Severity associated with strain and immunity

Question 5

What is IV vaccine efficacy dependent on

Answer 5

Match between vaccine antigen and circulating virus

Question 6

Influenza infection

Answer 6

• Usually self limiting with recovery in 3-7 days
• Can cause severe illness or death in high risk populations
• IVB never caused pandemic only epidemics

Question 7

What is traditional egg based IV vaccine production being replaced with

Answer 7

Cell based production

Question 8

Coronavirus

Answer 8

• Group 4 (+)ssRNA
• Coronaviridae family
• Seven CoV infect humans

Question 9

High pathogenic CoV

Answer 9

• SARS-CoV
• MERS-CoV
• SARS-CoV-2

Question 10

HCoV 229E and HCoV OC43

Answer 10

• Most commonly associated with URT, also cause LRT infections (fatal in immunocomprimised)
• Colds due to OC43 are more severe and indistinguishable from colds due to rhinoviruses
• Associated with ~13% of asthma exacerbations

Question 11

Severe Acute Respiratory Syndrome (SARs)

Answer 11

• Transmitted via droplets and close contact
• SARS-CoV causes lower RT disease
• Infection causes fever, malaise, coagulopathy
• Viral pneumonitis
• Gastrointestinal infection and disease

Question 12

Middle Eastern Respiratory Syndrome (MERS)

Answer 12

• Fever, cough, shortness of breath
• Pneumonia and gastrointestinal symptoms
• beta CoV
• Humans are infected through direct or indirect contact with infected dromedary camels

Question 13

Viral dissemination into body organs

Answer 13

• Initial replication takes place in URT, followed by migration of virus to lungs
• Primary viremia occurs after establishment of infection and replication in lung pneumocytes
• Viremia disseminates virus throughout body via blood stream

Question 14

Hantavirus Pulmonary Syndrome (HPS)

Answer 14

• (-)ssRNA, segmented
• Bunyaviridae (Hantavirus)
• Severe (40% fatality rate)
• Flue like illness progressing to pulmonary oedema and cardiovascular collapse
• Deer mouse reservoir

Question 15

Virus that disappeared during COVID-19

Answer 15

IVB-Yamagata