What is influenza (the flu)?

Influenza is a viral infection of your nose, throat and sometimes your lungs, but it can affect your whole body. It is a serious viral infection that carries the risk of hospitalisation or even death. Influenza can sometimes be confused with the common cold, but having the flu is a lot more debilitating. Vaccination against seasonal influenza is available each year in the autumn.

Serious effects possible

The National Influenza Strategy Group reports, on its website (March 2010), that approximately 400 deaths each year in New Zealand are related to influenza infection.

For the vast majority of people, influenza will make you unable to work, play sport or take planned holidays. It can infect your family or leave them looking after you. Special care is needed when children, the elderly or those with long-term health problems get influenza - in these people it can be serious and life-threatening.

Pregnant women are also at risk of complications from the 'swine flu' strain. The 2011 seasonal influenza vaccine includes protection against the swine flu (A/H1N1 pandemic influenza), so pregnant women are being encouraged to have the 2011 influenza vaccination, at no charge. See www.fightflu.co.nz

How do you get the flu?

The influenza virus is very infectious and is spread from person to person by the fine spray expelled from the nose and mouth when you cough or sneeze. The strains of virus that cause influenza are always around us. They constantly change, so having had the flu before does not stop you getting it again.

What does having the flu feel like?

You are likely to have a combination of symptoms including cough, sore throat, runny nose and eyes, headache, and usually high fever or chills, fatigue, aching muscles and joints and, in some people, breathing difficulties.

These symptoms can last for up to a week and will keep you in bed for a number of days. It will probably be a few weeks before you feel like you've fully recovered from the flu.

Occasionally, the infection spreads to the lungs, causing bronchitis or pneumonia. This is more likely in the elderly, heavy smokers and people in poor health, eg, with asthma or other chest complaints.

What makes the symptoms of flu better?

• Resting in bed until you feel better and the fever goes.
• Drinking at least eight glasses of fluid (water, fruit juice, cordial, iceblocks) a day. This is very important when you are sweating and feverish. Avoid tea, coffee and alcohol - they can dry you out even more (fresh lemon juice mixed with honey, some hot water and a little olive oil, well shaken then sipped, can soothe a sore throat or dry cough).
• Eating only light food when you are hungry. 
• Taking medicine for fever and pain (do not give aspirin to children aged under 16 years; ask your pharmacist for product advice, eg, children's paracetamol, and follow instructions on the bottle carefully). 
• Children under 6 years: most medicines for flu, coughs and colds contain ingredients which are not recommended for use in children under 6 years. Ask your pharmacist for product advice for young children
• Talking to your doctor or pharmacist about an antiviral medication that can reduce the amount of time you are unwell. This medicine needs to be taken within 48 hours of getting the symptoms of the flu (aching joints and fever) to be effective. You will need to pay for this medicine as it is not subsidised by the government.

How can my doctor help?

Contact your doctor if you have not improved after four days, you are elderly or you have other long-term health problems. Young children with flu also need to be assessed by their doctor. NOTE: To avoid spreading flu virus, particularly the swine flu strain, it is recommended to phone your doctor or health clinic before turning up at the surgery, clinic or hospital. You can also phone Healthline, free on 0800 611 116 for advice.

Influenza is caused by a virus so antibiotics do not help unless you get a secondary bacterial infection (eg, pneumonia or chronic sinusitis) following the flu.

How do I protect against influenza?

If you do not want to risk getting influenza you should have the influenza vaccination in the autumn each year. This will protect you from the most common strains of flu virus that are around over the peak flu season (winter).

The influenza vaccine is provided free each year for a specified period (till 31 July in 2011), for those at high risk of complications from the flu - ie, those aged 65 years and over, and those who are under 65 years and have long-term health problems (such as heart disease, cancer, stroke, respiratory diseases such as chronic bronchitis and asthma, diabetes, kidney disease, and autoimmune disease, among others).

2011 vaccine includes swine flu protection

The 2011 seasonal influenza vaccine again includes protection against the 'swine flu' (A/H1N1 pandemic influenza), as well as two other flu strains. To find out more about those groups who qualify for a free 2011 vaccine (which includes pregnant women), see our topic on Influenza vaccination and visit: www.fightflu.co.nz

Further information

For more about the influenza vaccine call your doctor or practice nurse, or contact the Immunisation Advisory Centre (IMAC) - for details see Further Information and Support below.

Written by the everybody editorial team. Reviewed by IMAC. Updated by everybody, May 2011.