Influenza
flu; influenza; cold; epidemic; pandemic; immunise; immunisation; vaccine; vaccination; immunization; reye's; reye; syndrome; bird; swine ;
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.
- Children and adults with 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 very 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). In 'closed' groups, such as families or school classes, many more children and adults may become unwell.
- 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. Other pandemics occurred in 1957-1958 and 1968-1969. (See the sections Swine flu and Preventing pandemics below for more information.
Time influenza takes to develop
- People usually get the flu one to three days after coming into contact with it.
Infectious period
- It is usually infectious from about 1 day before becoming unwell, to 3 to 5 days after the symptoms start (but can be up to 7 days in young children).
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 the child or adult 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 (children often recover more quickly than adults).
- Most people recover fully from the flu without 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).
Other health problems from flu
- The fever may trigger a febrile convulsion (fit) in young children. (See the topic 'Febrile convulsions')
- Flu can cause croup, bronchitis, ear infections, sinusitis, vomiting, diarrhoea, and pneumonia (viral or, more commonly, bacterial infection of the lungs).
- If a child develops pneumonia, instead of starting to become well after several days, he remains unwell, the cough continues and may get worse, and he can get short of breath.
- This mostly happens in children who have other health problems, such as cystic fibrosis, heart disease or other major problems that affect the immune system (such as cancer or HIV/AIDS).
- The flu can also damage the heart (ie. myocarditis) or brain (encephalitis), but these problems are rare.
- Elderly people, Aboriginal or Torres Strait Islander people over about 50 years old and people who are already not well are more likely than children to become seriously ill and die from influenza.
Influenza and child deaths
Recently 3 children died in Western Australia from influenza. It appears that all of the children had influenza A as well as another infection, and that the combination of these infections caused very severe and quickly fatal illnesses. Before these deaths the same type of flu has not caused a particularly severe illness. Deaths of children from influenza are very rare.
Parents of sick children should take them for medical attention early if children have respiratory illness such as cough or difficulty breathing, with fever, weakness and unusually sleepy. However symptoms such as a 'cold' with a runny nose, coughing, sneezing, but no fever is a cold, not the flu.
There is antiviral medication for influenza, but this must be started within 48 hours of onset of symptoms if there is to be any benefit at all, such as decreasing the severity and duration of the illness, but it is not a rapid cure.
The South Australian Department of Health is encouraging people to get this year's influenza vaccination soon if they have not had one, as vaccination remains the best means of preventing influenza. Influenza vaccine is not free for most people.
The vaccine can be given to children over 6 months and adults.
Vaccination of older children and adults (who need only one injection) will protect unvaccinated children by reducing the amount of infectiousness in the community.
People with infulenza need to stay home from work if they are sick, so as to reduce spreading the infection to others.
What you can do
- Most children with influenza will be quite ill for several days and they should be seen by a doctor early, or if they get worse. (Because they will also be infectious if they are coughing, tell your doctor's receptionist they may be able to give you an appointment when few other people will be there).
- The aim of looking after a child with the flu is to make the child as comfortable as possible, and prevent the spread of infection.
- Do not send a child who may have the flu to school, preschool or child care.
- While they have a fever, children should rest. Paracetamol or ibuprofen can be given for high fever, sore throat and headache (see the topic 'Using paracetamol or ibuprofen')
- Extra drinks should be given (eg breastfeeds, water, diluted fruit juice, milk).
- Soft, cool foods may help children to eat if they have a sore throat.
- Children often don't want to eat during influenza. This is not a problem if they continue to drink well; they will get back any lost weight quickly when they are over the flu.
- Some anti-viral medications have been developed, but most people will not need them.
- Antibiotics are only of use if a child develops 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 the child will get tired easily, and (very rarely) the infection may have harmed the heart.
The topic Feeling sick has suggestions for caring for a sick child.
Reye's syndrome
- Never give aspirin to children with influenza - there is an increased risk of a serious illness known as Reye's Syndrome if a child under 16 years takes aspirin when they have influenza or some other viral infections such as chicken pox.
- Reye's syndrome is a rare illness causing severe damage to the brain and liver, and it is often fatal even when the child is given intensive care.
Prevention of spread
- Stay away from people who are sick.
- Do not send a child who may have the flu to school, preschool or child care. Other children, and teachers, are very likely to catch flu, and teachers do not have enough time to look after sick children.
- Adults with the flu should also stay away from others (don't 'soldier on').
- A child with influenza should rest at home during the infectious period and keep away from others as much as possible.
- Teach children to cover their mouth or nose with a paper tissue each time they cough or sneeze. Tissues should be put into a bin after they are used and the children should then wash their hands.
- It has been suggested that children be taught to cough into their elbow rather than their hand, so that their hands will not have so many germs on them (this may be useful).
- If handkerchiefs are used, they need to be handled carefully (washing hands after touching them). Bleach, drying in the sun and ironing will all kill viruses.
- If you have been looking after a sick child, wash your hands often, especially after holding the child and touching used tissues or handkerchiefs. This will help to prevent spreading the infection to yourself and others.
- 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.
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.
- In Australia, yearly vaccination is recommended for (and may be provided free for):
- All people over the age of 65 years (this may be given with pneumococcal vaccine),
- All Aboriginal and Torres Strait Islander people over 50 years (with pneumococcal vaccine),
- Children (over 6 months old) and adults with heart disease, severe lung disease (such as cystic fibrosis), chronic illnesses (such as diabetes which is bad enough to cause the person to need care in hospital often), or people who have damage to their immune system (such as those having treatment for cancer or severe asthma, or those with HIV/AIDS),
- People who live in nursing homes or other long term care,
- Contacts of high-risk people, such as health care workers and family members of people who have health problems in the list above.
- It is probably useful for people with severe asthma, pregnant women (there is no evidence of any damage to the developing baby), people in some workplaces (such as schools) and travellers to be immunised, though these people will probably not get the vaccine free of charge.
- In Australia, anyone else can request and receive immunisation against influenza, although they will usually have to pay for the vaccine.
Side effects of immunisation
- Soreness, swelling and redness at the site of the injection are common (occurs in more than 10% of people),
- Mild flu-like symptoms sometimes occur for one or two days following vaccination (in about 5% of people). The vaccine does not have any live viruses in it, so it cannot cause flu.
- People who are very allergic to egg protein may have an allergic reaction (talk to your doctor before having the immunisation if you have an egg allergy).
For up-to-date information about swine flu (Influenza A H1N1) in South Australia have a look at the Department of Health website http://flu.sa.gov.au/
- 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.
- People travelling within and between countries occurs more rapidly and on a much larger scale now than in the early 1900s, and 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:
- Immunisation of people who work with farmed poultry (this should be done routinely).
- Immediately stopping movement of farmed poultry.
- Killing of poultry.
- Protection of people involved in culling poultry (immunisation, proper clothing and equipment, use of protective anti-viral drugs)
- Isolation of people who may be infected (using information gained from the SARS epidemic).
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
National Health and Medical Research Council (NHMRC). 'The Australian Immunisation Handbook, 9thth Edition 2008'.
South Australian Department of Health 'Influenza'
http://flu.sa.gov.au/
South Australian Department of Health 'Influenza: Seasonal, Pandemic and Avian Influenza'
http://www.dh.sa.gov.au/pehs/ygw/influenza-pehs-sahealth-2009.pdf
The Australian Department of Foreign Affairs and Trade: 'Smartraveller' provides information for international travellers.
http://www.smartraveller.gov.au/
International
World Health Organisation (WHO) internet site: has frequent updates being posted about current concerns about Swine Influenza (Influenza A (H1N1)
http://www.who.int/en
WHO, Pandemic Preparedness:
http://www.who.int/csr/disease/influenza/pandemic/en
National Institute of Neurological Disorders and Stroke 'Reye's Syndrome Information Page'
Click here
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 Parent Helpline on 1300 364 100 (local call cost from anywhere in South Australia).
This topic may use 'he' and 'she' in turn - please change to suit your
child's sex.