Resources and links
A collection of resources and links relating to influenza including alerts, campaigns, immunisation and medicines information
Influenza, commonly known as the flu, is a highly contagious infection of the nose, throat and lungs caused by the influenza A or B (or rarely C) viruses.
Influenza is a notifiable condition
In South Australia, influenza is most common in the winter months.
Influenza causes a spectrum of illness from asymptomatic infection to fatal pneumonia (primary viral or secondary bacterial). Severe disease is more common in pregnancy, people aged over 65 years and in people with underlying chronic disease.
Doctors should consider influenza in anyone with:
Most people with uncomplicated influenza recover within a week, although the cough and fatigue may last longer.
Spread is via respiratory droplets and direct contact with respiratory secretions.
Incubation period is 1 to 4 days (average 2 days).
People infected with influenza are considered infectious from 1 day before onset of symptoms up to 7 days from onset of symptoms. Viral shedding is greatest in the first 3 to 5 days of illness. Young children may shed virus for longer, up to 7 to 10 days. Viral shedding may continue for longer in severely immunocompromised persons.
In mild illness laboratory testing is not always necessary.
Take a deep nasal or throat swab, or sputum for respiratory viral testing. Use appropriate personal protective equipment when obtaining the sample.
Is your patient pregnant or has recently given birth? The Managing pregnant women with suspected influenza fact sheet (PDF 75KB) provides health professionals with information on influenza prevention, testing, treatment and prophylaxis in pregnant women. Important considerations in influenza management during each trimester, delivery and in the post-partum period are also discussed.
The Communicable Disease Control Branch, South Australia should be notified within 3 days of suspicion or confirmation of influenza on either on:
The Communicable Disease Control Branch conducts state-wide surveillance of all notifiable conditions (including influenza) in South Australia. This includes a chart that provides a regular update on influenza activity in South Australia.
Nationally, the Australian Influenza Surveillance Report and Activity Updates provides national data monitoring influenza activity and severity.