Influenza

Question 1

Definition

Answer 1

Acute viral respiratory infection caused by RNA influenza viruses

Question 2

Types

Answer 2

Influenza A - most virulent - epidemics and pandemics
Influenza B - co-circulated with influenza A but causes a less severe illness
Influenza C - Causes a mild or ASx infection

Question 3

Pathophysiology

Answer 3

The virus invades and then replicate in the epithelial cell lining of the upper and lower respiratory tract. Localised inflammation and subsequent immune reaction to the viral infection cause respiratory symptoms and systemic symptoms. Symptoms of the disease appear abruptly around 2 days after exposure.

Question 4

Epidemiology

Answer 4

Close proximity to infected people
Age 65 +
Immunocompromised

Question 5

Signs

Answer 5

Respiratory signs:
- Raised resp rate
- Rhinorrhoea
- Reduced air entry or crackles on auscultation
Pyrexia

Question 6

Symptoms

Answer 6

Respiratory symptoms:
- SOB
- Coryza
- Cough
Non-specific symptoms
- GI disturbances
- Fever
- Myalgia

Question 7

Diagnosis

Answer 7

Clinical diagnosis
GOLD STANDARD: Nasopharyngeal swab

Question 8

Treatment

Answer 8

Majority self limiting and do not require treatment
FIRST LINE: Antiviral treatment = ORAL OSELTAMIVIR
- Given to at risk group or evidence of severe or complicated influenza
- Should be started 48 hours of symptom onset

Question 9

At risk group

Answer 9

• Age >65 years
• Chronic respiratory disease
• Chronic heart disease
• Chronic kidney disease
• Chronic liver disease
• Chronic neurological conditions
• Diabetes mellitus
• Immunosuppression due to disease or treatment
• Morbid obesity (body mass index of 40 or more)

Question 10

Vaccination

Answer 10

Influenza vaccination is provided yearly in the UK for people over the age of 65 , eligible patients, and healthcare professionals

Question 11

Complications

Answer 11

Secondary bacterial pneumonia
Otitis media
Encephalitis
Myocarditis
Pericarditis