8. Respiratory Viruses

Question 1

Types of paramyxoviruses:

Answer 1

1. Measles
2. Mumps
3. Parainfluenza, Human Metapneumovirus (HMPV), Respiratory Syncytial Virus (RSV)
4. Human coronavirus

• related to measles, mumps & respiratory tract infections

Question 2

Characteristics of Measles:

Answer 2

• airborne spread
• affect endothelial & immune cells
• symptoms: measles rash, koplik spots, fever, respiratory tract problems
• live attenuated vaccine (lowered pathogenicity)

Question 3

Characteristics of Mumps:

Answer 3

• airborne spread
• affects pancreas, parotid glands, testes (usually harmless until testes infected)

Question 4

Characteristics of Parainfluenza, Human Metapneumovirus (HMPV), Respiratory Syncytial Virus (RSV)

Answer 4

• mild common cold, pharyngitis
• parainfluenza: laryngotracheobronchitits (croup)
• RSV: bronchiolitis (esp in premature babies), pneumonia in immunocompromised hosts

Question 5

Characteristics of Human coronavirus

Answer 5

• SARS: from bats
• MERS: from camels (epidemic in south korea & middle east)
• SARS-Cov-2

Question 6

Live attenuated vaccine is contraindicated in…

Answer 6

Contraindicated in immunocompromised patients

• cuz live attenuated vaccine is a weakened form of the virus

Question 7

Another name for influenza viruses:

Answer 7

Orthomyxovirus

Question 8

Characteristics of orthomyxoviruses (influenza)

Answer 8

• enveloped, -ve ssRNA, 8 gene segments
• has antigens, (hemagglutinin & neuraminidase) on membrane, inserted into viral envelope => envelope glycoproteins

Question 9

How is influenza(orthomyxovirus) spread?

Answer 9

• large droplets (from sneezing & coughing) & contact
• aerosols from respiratory secretions

Question 10

How is paramyxovirus spread?

Answer 10

• usually through airborne droplets
• through exhaled air, respiratory discharges, excrement, eggs laid by sick birds

Question 11

What is the difference between antigenic drift and antigenic shift?

Answer 11

Antigenic drift: accumulation of a series of minor genetic (RNA) MUTATIONS
- responsible for SEASONAL CHANGE of antigenicity => yrly immunisation
Antigenic shift: ‘MIXING’ of genes from influenza viruses from different species/ REASSORTMENT among 8 gene segments ( e.g. pig human bird)
- responsible for PANDEMIC

Question 12

What type of virus is likely responsible for pneumonia in healthy young ppl?

Answer 12

Adenovirus

Question 13

We require yearly vaccinations for influenza virus because of?

Answer 13

Antigenic drift