Influenza - the flu
influenza; flu; swine; pandemic; epidemic;
Contents
Many people are unsure whether they have a cold or influenza (the flu). The flu is quite different to a cold. It lasts longer and people are usually much more unwell with it. The flu is caused by a few slightly different types of influenza viruses, while colds are caused by many different viruses.
What is influenza?
- Influenza is an illness that usually starts quite suddenly, about 1 to 3 days after a person is in contact with someone who has the infection.
- People who have the flu often feel very unwell, and develop a fever, headache, body aches and loss of appetite. They have a runny nose, cough and chills (they feel cold and shivery even though their temperature is high).
- The viruses causing flu often change a little, so that people who have had flu before may not be protected by their immune system, and can get flu again.
- In most years there are outbreaks of flu in winter which can affect 5% to 10% of the population (epidemics).
- Several times a century, the viruses change a lot and cause a very large number of people worldwide to become very unwell (this is called a pandemic). In 1918-1919, an estimated 40 to 50 million people died from influenza around the world. Other pandemics occurred in 1957-1958 and 1968-1969. (See the sections Swine influenza and Preventing pandemics below for more information.
Infectious period
- It is usually infectious from about 1 day before becoming unwell, to 3 to 5 days after the symptoms start.
How is flu spread?
- Influenza is spread through droplets, when a person who is ill with the flu coughs or sneezes (the droplets can travel up to a metre).
- The droplets may fall directly onto the mouth or nose of another person, or on to surfaces from which they can be carried by hand to the mouth or nose.
Symptoms of influenza
- Some people have the infection, but only get a mild illness, and some do not become ill at all.
- For those who become ill, the flu usually starts suddenly with *feeling very unwell, with a fever, headache, runny nose, cough, loss of appetite and body aches.
- The severe illness may last for 2 or 3 days, then often the person will still be unwell, tired and lacking energy for many more days, sometimes more than a week.
- Most people recover fully from the flu without the need for special treatment, but some need treatment for complications such as pneumonia, and a small percentage die (usually elderly people or those who already have health problems).
What you can do
- Do not go to school, work or any other place where there are other people when you have the flu.
- Put used tissues in a bin or flush them down the toilet.
- Wash hands often - especially before handling food that others may eat.
- Rest.
- Paracetamol or ibuprofen can be taken for high fever, sore throat and headache.
- Some anti-viral medications have been developed, but most people will not need them.
- Antibiotics are only of use if you develop another infection due to the flu, such as an ear infection or pneumonia.
- After the symptoms go, it is better to take things slowly for a while (especially avoid vigorous exercise) because you will get tired easily.
- Anyone who is ill should avoid close contact with elderly people and people with other illnesses (especially if they have not been immunised), as they are more likely to get health problems from the flu.
To help you avoid getting the flu stay away from people who are sick.
Immunisation against influenza
- A new influenza vaccine is produced each year because of the changes that happen to the virus, and people need to have their 'flu shots' each year.
- Vaccination is given in autumn, before the winter outbreak of flu.
- Any one over 6 months old can be immunised against the flu, but the vaccine is only free to adults over 65 and aboriginal people over 60 years old.
Swine flu
- Human swine influenza A (H1N1), commonly known as swine flu, is a new type of human influenza virus. This virus is spread from person to person.
How is swine flu spread?
- Human swine influenza is thought to be spread when infected airborne droplets, produced by coughing or sneezing by someone with the infection, come into contact with a mucous membrane (lining of the nose and mouth).
- Infection may also be spread by contact with hands, tissues and other articles soiled by infected nose and throat discharges.
What are the symptoms?
- Symptoms of swine flu in humans are a lot like those produced by standard, seasonal flu. These include fever and cough, sore throat, fatigue and respiratory illness.
For up-to-date information about swine flu in South Australia have a look at the Department of Health website
http://flu.sa.gov.au
Preventing pandemics
- Based on historical patterns, influenza pandemics (which can affect the whole world) can be expected to occur, on average, 3 to 4 times each century, when new viruses emerge and spread very quickly from person to person.
- Nowadays many people travel around their country and to other countries quickly. This means that the flu will spread very rapidly. So the next great influenza pandemic has the potential to cause hundreds of millions of deaths. The World Health Organisation has stated that 'experts agree that another influenza pandemic is inevitable'.
- Strategies that will be used to try to prevent a pandemic include isolation of people who may be infected (using information gained from the SARS epidemic).
- Many airports are using machines which can detect anyone with a high temperature coming into the country so that they can be checked out medically before going into the wider community.
The World Health Organisation has influenza pandemic plans, which can be accessed via the WHO Internet site: http://www.who.int/csr/disease/influenza/pandemic/en/
Resources and references
Australia
International
The information on this site should not be used as an alternative to professional care. If you have a particular problem, see a doctor, or ring the Youth Healthline on 1300 13 17 19 (local call cost from anywhere in South Australia).