Flu (influenza)

Influenza, commonly known as the flu, is caused by a highly contagious virus that is spread by coughs and sneezes. There are three types of flu virus – A, B and C. Older people and those with an underlying medical condition are more likely to develop serious complications as a result of the flu.

The flu virus has a unique ability to change its surface structure. This allows it to escape recognition by the body’s immune system and cause widespread illness (epidemics and pandemics). Most cases of influenza occur within a six to eight-week period during winter and spring.

Epidemics occur when there are minor changes in the nature of the virus so that more people within a community are susceptible, for example the elderly. Influenza A is more likely to cause epidemics. Pandemics (worldwide epidemics) occur when there are major changes in the virus so that the disease affects a large proportion of people in a geographic region or continent.

Influenza epidemics occur, on average, every three years. Influenza pandemics have occurred three times in the past 100 years and can cause very many deaths.

Flu symptoms
Flu symptoms develop one to three days after infection and include:

• High fever, chills and sweating
• Sore throat
• Weakness
• Headache
• General muscle and joint pains (legs and back)
• A non-productive cough that can later become more severe and productive.

• Cold symptoms last one to two days while the flu can last up to a week.
• The flu causes a high fever. A cold sometimes causes a mild fever.
• Muscular pains and shivering attacks occur with the flu but not with a cold.
• Colds cause a runny nose, while the flu usually starts with a dry sensation in the nose and throat.

• Secondary bacterial pneumonia – occurs when bacteria invade the lungs. Symptoms include shortness of breath, green–yellow phlegm, chest pains and a temperature. Death rates are high but it is less lethal than primary influenza pneumonia.
• Primary influenza pneumonia – almost always results in death. Symptoms include difficulty breathing and blue discoloration of the skin (cyanosis).
• Inflammation of the brain or heart – can occur during recovery from the flu.
• Reye’s syndrome – leads to brain inflammation and liver degeneration and is fatal in between 10 and 40 per cent of cases. Children under 16 years should not be given any medication containing aspirin as it increases the risk of Reye’s syndrome.

• Everyone aged 65 years and older
• Aboriginal people and Torres Strait Islanders aged over 50
• Aboriginal people and Torres Strait Islanders aged between 15 and 49 years with health risks
• All public hospital outpatients and inpatients with high risk factors.
• Public hospital staff who provide direct care to patients.
• Anyone from six months of age with heart disease, chronic lung disease, chronic neurological conditions, impaired immunity and other chronic illnesses such as diabetes, kidney disease and haemoglobinopathies
• Residents in nursing homes or other long-term care facilities
• Staff in private hospitals, long-term care facilities or nursing homes
• People who live with, or care for, someone who has a chronic illness or is aged
• Severe asthmatics who require frequent hospital visits
• Pregnant women
• Children on long-term aspirin therapy
• Anyone travelling as part of a group
• Workers, particularly those in workplaces that provide essential services
• People involved in the commercial poultry industry
• Workers in other ‘high risk’ industries.

• Stay in bed and rest until the temperature has been normal for 48 hours.
• Drink enough fluids to maintain normal urine output.
• Take paracetamol to control fever, aches and pains (adults can use aspirin). Early use of antiviral medication may shorten the length and severity of illness. Consult a doctor to discuss treatment.
• Avoid exposure to dust, alcohol, fumes and tobacco smoke as much as possible.

• Your doctor
• Nurse on Call Tel. 1300 606 024 – for expert health information and advice (24 hours, 7 days)
• Your local Council
• Your local community health centre
• Immunisation Program, Department of Health Victoria Tel. 1300 882 008
• National Immunisation Infoline Tel. 1800 671 811
• The emergency department of your nearest hospital

• The flu is more than just a bad cold.
• Flu can occasionally lead to serious complications including death.
• Older and ‘at risk’ groups should be immunised every year against the flu.
• Protection after immunisation takes 10 to 14 days.

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