Influenza is a contagious lung infection caused by the influenza virus.

It is more commonly known as ‘the flu’.

There are 3 types of flu virus, types A, B, C.

Each year, the virus changes (mutates) and makes a new version of itself.

You won't be immune to a new flu strain unless you have been sick with that flu before or have received a vaccine specifically designed for that strain.

This is why flu vaccines are recommended every year.

How is it spread

The flu is very infectious and spreads person to person by:

  • breathing in small droplets that come out the mouth and nose of infected people when they cough and sneeze
  • touching surfaces that infected people have coughed or sneezed on and then touching your mouth or eyes.

You are most infectious when you have a cough and fever.

Adults can spread the flu the day before symptoms start and up to 7 days after.

Children can spread the flu for 10 days or longer.

People with weakened immune systems can spread the flu for weeks.


You usually start to get flu symptoms 1 to 3 days after you were exposed to the virus.

They come on quickly and can include:

  • tiredness
  • fever
  • headache
  • chills
  • sore throat
  • loss of appetite
  • muscle aches.

You may also have a cough, runny nose and sneezing.

Who is at risk

How sick you become with the flu depends on:

Flu outbreaks are common at aged care facilities and residents are a high risk group. For that reason, you must have a flu vaccination to enter an aged care facility in the NT.


The best way to recover from the flu is to get:

  • plenty of rest
  • drink water
  • take pain relief medication if needed.

Anti-viral treatment can help if it is taken within 48 hours after symptoms start. These can help shorten your illness and reduce the severity, especially if you are in hospital.


To stop the spread of flu, practice good hygiene by:

  • coughing or sneezing into your upper arm
  • use a tissue and dispose immediately
  • wash your hands regularly
  • wear a mask when infectious
  • stay home when you’re sick.


Getting a vaccine every year is recommended, especially for those most at risk.

The influenza vaccine is safe and effective. It does not contain any live virus, so people cannot catch influenza from having the vaccine.

After you’ve had the vaccine, it takes around 2 weeks before the body is protected.

Read more about the flu vaccination.

Information for health professionals

To find out more go to the NT Health website.


For more information call your nearest Public Health Unit’s Centre for Disease Control.

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