Influenza, or flu, is an acute viral infection that affects millions of people of all ages around the world and is caused by different types of infleunza virus. It is a major public health problem and can result in potentially serious medical complications, such as pneumonia, which can lead to hospitalisation, and can even result in death.
You can catch flu all year round, but it is especially common in autumn and winter, which is why it is also known as 'seasonal flu'. Flu is mainly spread by coughs and sneezes, and can sweep through schools, the workplace, nursing homes and even whole communities.
Flu is not the same as the common cold. It is caused by a different group of viruses. Symptoms of flu tend to be much more severe and may last for longer. Flu has a number of symptoms, some more serious than others. It is usually accompanied by a high temperature, tiredness, sore throat and general aches and pains. You can lose your appetite, feel nauseous and have a cough. Adults (but more commonly children) may also experience diarrhoea and vomiting. Flu symptoms can make people feel so exhausted and unwell that they have to stay in bed and rest until they feel better.
Flu is highly contagious and can spread easily from person to person. So family members (particularly the elderly and young children) and work colleagues are at risk of getting infected if they come into contact with someone who has flu. The best solution to avoid infecting others is to stay at home and avoid contact with other people until you are better.
It is difficult to treat flu successfully. You can stop flu spreading by staying at home, using tissues to cover your nose and mouth and washing your hands regularly. According to the WHO (World Health Organization), vaccination is the most effective way to prevent infection and protect against the consequences of flu.
The seasonal flu vaccine helps provide protection against infection by the viruses included in the vaccine. The vaccine you received last year might not contain the strains which circulate this year. So, for optimal protection against flu, annual vaccination is recommended.
The Australian Immunisation Handbook recommends annual vaccination for the following groups that may suffer more serious consequences if infected with flu: