wcdhb banner

Influenza Explained

What is Influenza (Seasonal Influenza)?

Influenza (the flu) is a highly infectious illness caused by a virus. It is much more serious than a common cold and will leave you ill for up to 10 days.  Symptoms of the flu start suddenly and include:

  • A high fever
  • Headache
  • Muscle aches and pains
  • Fatigue
  • Cough
  • Sore throat, or
  • A runny nose

How is influenza diagnosed?

The diagnosis is usually based on the appearance of specific signs and symptoms of influenza. Confirmation can be achieved through laboratory testing of throat specimens or blood samples.


Who can get it?

Anyone can get influenza - being fit, active and healthy does not protect you from getting this virus.



How severe does it get?

Influenza can be a mild or severe illness depending on the type of influenza virus causing it, and the age and general health of the person affected.

Anyone can die from influenza - it kills at least 100 New Zealanders every year, including some young, fit people.


When Do Symptoms Show?

It may take up to three days to show symptoms when you catch the flu.


For how long is an infected person able to spread influenza (contagious)?

An infected person can spread influenza virus in discharges from their nose and throat from 24 hours before the onset of their illness and right up to 3-5 days after the onset of illness.

Young children and persons with a weakened immune system can spread the virus for 7 days or even longer.