Influenza (flu)

Influenza (flu) is an acute viral illness that is easily spread from person to person, mainly through particle droplets produced by coughing and sneezing. Influenza is most often caused by type A or B influenza viruses that infect the upper airways and lungs.

Flu is not the same as a common cold or COVID-19, but it can be a serious illness. For some people, such as young children, the elderly, and those with underlying medical conditions, the flu can cause serious complications requiring hospitalisation and can sometimes lead to death.

Children under 5 years old are at a higher risk of contracting the flu because they are still developing their immune systems. This means they are more likely to develop serious complications. Children with underlying medical conditions or those who are immunocompromised are also at greater risk of developing severe infections or serious complications from the flu.

Flu is one of the most common vaccine preventable causes of hospitalisation in young children.

How does it spread?

The flu is mainly spread by:

• airborne droplets when an infected person coughs, sneezes or talks
• touching surfaces contaminated by infected droplets (including hands, remote controls, phones, keyboards and door handles) and then touching your mouth, nose or eyes.

People with flu can be infectious to others from 24 hours before symptoms start until a week after the start of symptoms. Children and those who have compromised immune systems can be infectious for longer. Even people with mild flu illness can transmit the infection.

Signs and symptoms

Symptoms usually appear 1 to 3 days after becoming infected. People are potentially infectious to others even before they have symptoms.

The symptoms of flu can include:

• fever
• sore throat
• dry cough
• headache
• muscle and joint pain
• tiredness or extreme exhaustion.

Children with flu can also have gastrointestinal symptoms (nausea, vomiting and diarrhoea).

Although some flu symptoms may be similar to a cold, the virus can also cause severe infections such as pneumonia. Other serious complications can include inflammation or swelling of the heart (myocarditis), brain (encephalitis) or muscles (myositis, rhabdomyolysis), and multi-organ failure (lung or kidney failure).

Who is most at risk of severe infection or complications from the flu?

The following people are most at risk:

• babies and young children (less than 5 years old)
• people with underlying medical problems
• the elderly
• Aboriginal or Torres Strait Islander people
• pregnant women.

Treatment

There is no specific effective treatment for influenza. Antibiotics are not effective against viral infections.

Care at home

Most children and young people with the flu can be safely cared for at home. The symptoms of flu are generally managed by:

• bed rest
• drinking plenty of fluids (particularly water)
• over-the-counter medication (paracetamol, ibuprofen) to help relieve pain, fever and discomfort symptoms (take as directed in the product information).

Most people recover from the flu within a week, although a cough and tiredness may persist.

When to seek help

See your GP if:

• you are concerned about your child’s symptoms
• your child has an underlying medical condition and has a cough and or high fever (38 degrees Celsius or more) that is not improving.

In an emergency, call Triple Zero (000) and ask for an ambulance, especially if your child:

• has difficulty breathing or shortness of breath
• is not eating or drinking and/or has fewer wet nappies than usual
• is extremely irritable.

If you're not sure whether to go to an emergency department, call 13 HEALTH (13 43 25 84) and speak to a registered nurse.

Stopping the spread

You can reduce the risk of infection by getting vaccinated, practising good hand and respiratory hygiene and staying at least 1 metre away from people who have flu symptoms. If you or your child has flu symptoms you should:

• keep them home from school and stay home if you are sick
• wash your hands regularly with soap and water or use an alcohol-based hand rub
• wash your hands before touching your eyes, nose, and mouth
• use a tissue, or the inside of your arm, when you cough and sneeze
• throw tissues away immediately and wash your hands
• don’t share items such as cigarettes, cups, lipstick, toys, or anything which has come into contact with the mouth or nose
• stay at least 1 metre away from people who have flu-like symptoms
• clean frequently touched surfaces regularly.

Vaccination

Vaccination is the best way to reduce the risk of getting the flu. Annual vaccination will boost your child’s immunity and provide protection against the most recent flu strains. It will also give the best protection against serious complications.

The flu vaccine is free under the National Immunisation Program for:

• children aged 6 months to less than 5 years
• people aged 6 months and older with medical conditions which increase the risk of influenza disease complications.
• all adults over 65 years
• pregnant women (at any stage of pregnancy)
• all Aboriginal and Torres Strait Islander people aged 6 months and over.

Vaccination is recommended for anyone aged 6 months and older who wishes to protect themselves from influenza and its complications. People who are not eligible for a free vaccine can purchase the vaccine from an immunisation provider for a small fee.

When should my child have the flu vaccine?

The flu season in Queensland generally runs from June to September, with the peak usually in August. Influenza can occur year-round, however. Whilst vaccinations provide the best protection 3 to 4 months after receiving the influenza vaccine, it is never too late to vaccinate.

Visit the Queensland Health influenza vaccination guidelines for the latest influenza vaccination information.

Can my child have the flu vaccine if they currently have/or recently had COVID-19?

Your child can have a flu vaccine if they are 6 months or older and they recently had COVID-19 but have no remaining symptoms (e.g. fever, sore throat, runny nose), or if the only remaining symptoms are a very mild dry cough which is persistent but not getting worse, mild fatigue or loss of sense of smell.

If your child has COVID-19 and are isolating at home, they should not receive a flu vaccine until their isolation period has finished (day 8 onwards).

Key points

• Flu symptoms include a runny nose, sore throat, cough, fever, headache and muscle aches. The virus can also cause severe infections such as pneumonia and more serious complications.
• Children under 5 years are at a higher risk of contracting the flu because they are still developing their immune systems.
• Vaccinations are recommended from mid-April to 31 May to provide the best protection during flu season.

For more information

• Queensland Health fact sheet: Influenza
• Queensland Specialist Immunisation Service

Developed by the Infectious Diseases Department, Queensland Children’s Hospital. We acknowledge the input of consumers and carers.

Resource ID: FS057. Reviewed: April 2022.

Disclaimer: This information has been produced by healthcare professionals as a guideline only and is intended to support, not replace, discussion with your child’s doctor or healthcare professionals. Information is updated regularly, so please check you are referring to the most recent version. Seek medical advice, as appropriate, for concerns regarding your child’s health.