Influenza

Question 1

Influenza is usually a self-limiting disease.

When can it be life-threatening?

Answer 1

In the elderly, pregnant women and people with chronic disease.

Question 2

Explain seasonal influenza.

Answer 2

An acute viral infection of lungs and airways.

It’s due to Type A, B or C

Question 3

Incubation of seasonal influenza.

Answer 3

1-4 days

The infectivity is from 1d prior to symptoms and around 7 days after symptoms.

Question 4

Presentation of seasonal influenza.

Answer 4

Fever

Dry cough

Sore throat

Coryzal symptoms

Headache

Malaise

Myalgia

Conjunctivitis

Eye pain

Question 5

Complications of seasonal influenza.

Answer 5

Pneumonia

Exacerbation of chronic lung disease

Croup

Otitis media

Diarrhoea and vomiting

Myositis

Encephalitis

Reye syndrome

Question 6

Diagnosis of influenza.

Answer 6

Acute onset of cough and fever has a positive predictive value of >79%. This clinical diagnosis is usually enough.

Testing is limited to outbreaks and public health surveillance.

Testing includes viral PCR, rapid antigen testing and viral cultures of clinical samples.

Question 7

Treatment of uncomplicated influenza.

Answer 7

Symptomatic treatment like paracetamol

Antivirals should only be used if high risk.

Question 8

Indications of antiviral use in uncomplicated influenza.

Answer 8

Chronic lung, heart, kidney, liver, CNS or DM disease.

Immunosuppression

Pregnancy

BMI > 40

> 65 yo

< 6 months old

Question 9

Treatment of complicated influenza

Answer 9

All need hospital admissions.

First line - Oseltamivir PO or NG 75mg BD 5 day course

or

Zanamivir inhaled, nebulised or IV.
This is only used if oseltamivir resistant or poor clinical response to oseltamivir

Question 10

Prevention of seasonal influenza.

Answer 10

Post-exposure prophylaxis - Oseltamivir for 10 days

Vaccination in all high risk , children > 2yrs and healthcare workers