Influenza – including symptoms, treatment and prevention
Influenza, commonly known as the flu, is an infection of the nose, throat and lungs caused by the influenza A or B (or rarely C) viruses. It is highly infectious.
Influenza is a notifiable condition1
How influenza is spread
The flu virus is spread when an infected person talks, coughs or sneezes small droplets that contain the virus into the air where they may be breathed in by people nearby. Infection may also be spread by contact with hands, tissues and other infected
Signs and symptoms
- rapid onset of fever
- muscle aches
- runny nose
- sore throat
- a cough.
Most people recover within a week, although the cough and fatigue may last longer. Flu is much more serious than the common cold. It can lead to pneumonia (lung infection or inflammation) and other complications, and even death, particularly in:
- people aged 65 years and over
- pregnant women
- young children
- people with chronic conditions like heart disease, diabetes and lung disease.
Influenza and pregnancy
Pregnant women are more likely to have severe complications from the flu, especially in the second and third trimesters. While the flu virus does not cross the placenta and infect the baby while in the uterus, the high fever and any chest complications caused by flu can be potentially harmful to the baby. Because of these risks, a doctor may recommend antiviral medication for pregnant women with the flu.
There is no evidence that the antiviral medications used in Australia to treat flu are associated with adverse effects in pregnancy. Similarly, women may continue to breastfeed while taking antiviral medication. The best protection for the mother and baby is for the pregnant mother to have the flu vaccine, which is safe and funded at any stage of pregnancy.
The diagnosis may be suspected on clinical symptoms and examination (especially during the flu season) and is best confirmed by laboratory testing of mucus from the back of the nose or throat.
(time between becoming infected and developing symptoms)
Incubation is 1 - 4 days (average of 2 days).
(time during which an infected person can infect others)
Usually from 1 day before
Most people recover with rest, drinking plenty of fluids and use of paracetamol for the relief of pain and fever. Aspirin should not be given to children under 12 years of age unless specifically recommended by a doctor.
People with moderate or severe illness, pregnant women, Aboriginal and Torres Strait Islander people and those with chronic medical conditions may benefit from specific antiviral medication. This can reduce
Antiviral therapy may sometimes be used to prevent infection in close contacts of people with flu, such as vulnerable household contacts. A contact is any person who has been close enough to an infected person to be at risk infection themselves.
When to seek medical advice
Seek medical advice if:
- shortness of breath or difficulty breathing occurs
- symptoms are getting worse
- you are concerned about the symptoms.
- Flu vaccines reduce the risk of getting severe influenza. Annual flu vaccination is strongly recommended for anyone 6 months of age and older and should be actively promoted for people at increased risk of complications.
- Cover a cough or sneeze with a tissue or your arm, not with your hand. Drop used tissues immediately into a rubbish bin, then wash your hands.
- Wash hands as soon as possible after sneezing or coughing and after contact with nose and throat discharges or articles soiled by these. Use soap and water or an
alcohol basedhand rub.
- Wipe down all frequently touched surfaces regularly with a cleaning cloth dampened with detergent, or a large alcohol wipe.
- Exclude people with flu from childcare, preschool, school and work.
- Annual flu vaccination is recommended for anyone 6 months of age or older who wishes to reduce the likelihood of becoming ill with flu
Annual flu vaccination is strongly recommended and should be actively promoted for people at increased risk of complications from flu infection or who may transmit flu infection to others who are at increased risk of complications.
Wash, wipe cover website – www.sahealth.sa.gov.au/washwipecover
- Exclusion periods from childcare, preschool, school and work
- Hand hygiene
- When you have a notifiable condition
1 – In South