Viral Respiratory Infections

Question 1

List 5 types of viral respiratory infection.

Answer 1

Common cold
Croup
Lower respiratory tract infections (LRTIs)
Pneumonia
Influenza

Question 2

Define croup.

Answer 2

Acute inflammation and obstruction of the respiratory tract, involving the larynx and main air passages (trachea and bronchi)

Question 3

Define bronchiolitis.

Answer 3

Inflammation of the bronchioles due to viral infection, especially respiratory syncytial virus (RSV)

Question 4

List 2 causes of the common cold.

Answer 4

Rhinovirus (80%)
-Groups A, B and C

Coronavirus (15-20%)

Question 5

Describe the symptoms of a common cold. (2)

How is treated? (1)

Answer 5

SYMPTOMS:
General malaise
Fever

TREATMENT:
Supportive treatment only

Question 6

Describe the symptoms of croup. (6)

What can happen in severe croup? (1)

Answer 6

Distinctive "barking" cough
Stridor
Laryngitis
High HR
Restlessness
Cyanosis

SEVERE CROUP:
Difficulty breathing

Question 7

Which viruses can cause croup? (1)

Answer 7

Parainfluenza viruses 1-4

Question 8

How do you treat croup?

Answer 8

Supportive treatment

Question 9

Describe the pathophysiology of bronchiolitis. (2)

Answer 9

1. Bronchioles become swollen, and lining cells die
2. Bronchioles become blocked with debris and mucous
   a. Therefore air cannot reach the alveoli
   b. This causes hypoxia and breathlessness

Question 10

Describe the clinical features of bronchiolitis. (5)

Answer 10

Breathlessness
Hypoxia
Wheeze
General malaise
Flu-like symptoms

Question 11

Which viruses can cause bronchiolitis? (1)

Answer 11

Respiratory syncytial virus (RSV)

Question 12

Who is at high risk of RSV infection?

Answer 12

Young children
Immunocompromised patients
Chronic lung disease
Elderly patients

Question 13

How do you prevent RSV infection?

How do you treat RSV infection?

Answer 13

PREVENTION:
Cohorting
PPE
Handwashing

TREATMENT:
Ribavirin (virazole)
Palivizumab (synagis)

Question 14

Describe the advantages and disadvantages of:

a) Ribavirin (2)
b) Palivizumab (3)

Answer 14

RIBAVIRIN:
Administration IV, oral or inhaled
Many adverse effects

PALIVIZUMAB:
Monthly IM injection
Reduces hospitalisation of high risk infants by 45%
Very expensive

Question 15

Describe the clinical features of viral pneumonia. (10)

Answer 15

Fever
Cough (with sputum/phlegm production)
Shortness of breath
Pleuritic chest pain
Haemoptysis

Other symptoms:

• Headache
• Nausea and vomiting
• Arthalgia
• Fatigue/weakness
• Cyanosis

Question 16

Which viruses can cause viral pneumonia? Which ones are common in:

a) Adults? (1)
b) Children? (3)
c) Immunocompromised patients? (2)

Answer 16

IN ADULTS:
-Influenza virus

IN CHILDREN:

• Influenza virus
• Respiratory syncytial virus (RSV)
• Type 3 parainfluenza virus

IN IMMUNOCOMPROMISED PATIENTS:

• Influenza virus
• Cytomegalovirus (CMV)

Question 17

What causes influenza epidemics?

What causes influenza pandemics?

Answer 17

Antigenic drift - “gradual changes in virus structure caused by mutations, allowing it to evade the immune system”

Antigenic shift - “significant changes in virus structure caused by large mutations, allowing the virus to jump species from animals to humans”

Question 18

List 5 common complications of influenza infection.

List 5 uncommon complications of influenza infection.

Answer 18

COMMON COMPLICATIONS:
Acute otitis media
Sinusitis
Pneumonia
Exacerbation of underlying diseases
Dehydration 

UNCOMMON COMPLICATIONS:
Encephalopathy
Reye's syndrome
Myositis
Myocarditis 
Febrile seizures

Question 19

List 8 risk factors for complications of influenza infection.

Answer 19

Extremes of age
Underlying lung conditions
Chronic CVD, renal or hepatic disease
Haematological disease
Metabolic disorders
Immunosuppression
Pregnancy
Long term aspirin therapy

Question 20

How do you treat influenza infection? (2)

Answer 20

Adamantanamine derivatives

Neuraminidase inhibitors

Question 21

Give 3 examples of neuraminidase inhibitors used to treat influenza.

Answer 21

Tamiflu (oseltamivir)
Rapivab (peramivir)
Relenza (zanamivir)

Question 22

List 5 benefits of PCR testing for viral DNA.

Answer 22

Highly sensitive
Rapidly developed
Can detect multiple pathogens
Semi-quantitative 
Very quick