Influenza

Question 1

What are requirements of a pandemic?

Answer 1

Human pathogenicity
New’ virus (antigenic shift) - susceptible population
Efficient person-person transmission

Question 2

What are the clinical features of influenza?

Answer 2

Abrupt fever up to 41°C (commonly 38-40°C) which lasts 3 days (range 1-5 days)

Plus 2 or more of: Cough, [sore throat, rhinorrhoea], myalgia, headache, malaise.

Predominance of systemic symptoms

Question 3

What is the WHO definition of influenza like illness

Answer 3

Fever (>38°C) and
Cough
Onset within the last 10 days

Question 4

What is SARI?

Answer 4

Severe acute respiratory infection

Influenza like illness requiring hospitalisation

Question 5

Risk factors for complicated influenza

Answer 5

Neurological, hepatic, renal, pulmonary and chronic cardiac disease
Diabetes mellitus
Severe immunosuppression
Age over 65 years
Pregnancy (including up to two weeks post partum)
Children under 6 months of age
Morbid obesity (BMI ≥40)

Question 6

Common complications of influenza

Answer 6

Acute Bronchitis
Secondary Bacterial Pneumonia
Primary viral pneumonia
Myocarditis/pericarditis
Transverse myelitis/Guillain-Barre
Myositis & Myoglobinuria

Question 7

CURB-65 for secondary bacterial pneumonia

Answer 7

Confusion
Urea >7mmol/l
Respiratory rate >30mm
Blood Pressure (diastolic <60 or systolic <90)
>65 years of age

Question 8

Antiviral therapy

Answer 8

Oral oseltamivir (tamiflu)
Inhaled & or IV zanamivir (relenza)

Question 9

Firstline antiviral therapy in pregnancy

Answer 9

Oseltamivir