Bird flu (Avian influenza) in humans – including symptoms, treatment and prevention
Avian influenza in humans, commonly known as bird flu, is an infection of the nose, throat and lungs caused by specific types of influenza A (flu) virus. In recent years the main types of bird flu have been H5N1 and H7N9. These types of influenza A cause infection in birds which can range from mild to severe. Human infections with bird flu are more serious than seasonal flu and have a higher fatality rate (percentage of people who die after getting the infection).
Avian influenza in humans is a notifiable condition1
How avian influenza is spread
Human to human spread of bird flu occurs rarely. However, the bird flu virus can change (mutate) and may then be able to spread between humans. In the past there have been global pandemics (infections in people all around the world) of bird flu in humans caused by these changed viruses. The main risk for human infection is direct or indirect exposure to infected live or dead domestic birds (for example chickens and ducks), or to environments contaminated by infected birds.
Signs and symptoms
Symptoms are usually similar to seasonal flu and include:
- rapid onset of fever
- muscle aches
- difficulty breating
- sore throat
- a cough
Bird flu in humans is much more serious than the common cold. While most people recover from bird flu within a week or two, the cough and fatigue may last longer. Infection can lead to pneumonia (lung infection) and other complications, including death. The following groups of people are more likely to have serious infections and complications:
- older people (aged 65 years and over)
- pregnant women
- young children
- people with chronic (long standing) conditions like heart disease, diabetes and lung disease
All people with flu-like symptoms returning to Australia who have had contact with birds in a country with human cases of bird flu, and people who have been in contact with other people with known or suspected bird flu, should be tested to establish the influenza type. This is best performed by laboratory testing of mucus from the back of the nose or throat. Testing to confirm the type of flu also allows doctors to see if the virus can be effectively treated with antiviral medicines.
(time between becoming infected and developing symptoms)
Average of 5 days for bird flu in humans (range 1 to 10 days), but this depends on the type of bird flu. The incubation period is usually longer than that for seasonal flu.
(time during which an infected person can infect others)
Usually from 1 day before onset of symptoms until 7 days after the onset of symptoms, but this can vary depending on the type of bird flu. After 5 days most people are much less infectious; however some people, especially children and people with weakened immune systems, might be able to infect others for a longer period of time.
Several antiviral medicines used to treat seasonal flu are also usually effective against bird flu. These can be used as treatment after a person develops symptoms of bird flu, or used to prevent illness in a contact of someone who was infectious with bird flu. A contact is any person who has been close enough to an infected person to be at risk of having got the infection from that person.
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.
When to seek medical advice
Seek medical advice immediately if you have recently returned from a country with a reported outbreak of bird flu and you get flu symptoms. If possible, ring the clinic before you arrive so when you arrive you can be given a mask and seated in an area where you are less likely to spread infection to others. Tell the clinic staff about your travel, including any visits to markets, farms or anywhere else where birds were present. You can look up which countries are affected by bird flu on the World Health Organization (WHO) website.
Be aware of the risk of bird flu if you are travelling to, or living in, a country where outbreaks are occurring in birds or humans. Prevention approaches include:
- Avoid contact with wild or domesticated birds. Don’t go to farms or market places where there are birds.
- Stop children from putting objects or their own fingers that may have had contact with infected birds or bird products (for example, feathers and bird droppings) into their mouths.
- Do not use cracked and/or dirty eggs and do not wash dirty eggs. Wash your hands thoroughly after handling eggs, as eggshells may be contaminated with bird droppings.
- Avoid foods that contain uncooked eggs, such as mayonnaise and mousse.
- Wash hands and utensils thoroughly after handling raw poultry (domestic birds).
- Cook poultry at high temperatures. Cooking temperatures of 80°C or higher destroys the bird flu virus in about 60 seconds. See Thawing, cooking, cooling and reheating food for more information.
When bird flu is confirmed by the laboratory test, it is important to take the following steps to reduce risk of further spread of the virus:
- Exclude people with bird flu from childcare, preschool, school and work until there has been no fever for at least 24 hours (without using a fever reducing medicine such as paracetamol).
- 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 based hand rub.
- Wipe down all frequently touched surfaces regularly with a cleaning cloth dampened with detergent, or a large alcohol wipe.
- 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.
The annual flu vaccine does not protect against bird flu. However, seasonal flu vaccine is recommended for anyone 6 months of age or older who wishes to reduce the likelihood of becoming ill with seasonal influenza.
Immunisation website – www.sahealth.sa.gov.au/immunisation
Wash, wipe cover website – www.sahealth.sa.gov.au/washwipecover
SA Health website – www.sahealth.sa.gov.au
- Exclusion periods from childcare, preschool, school and work
- Hand hygiene
- When you have a notifiable condition
WHO listing of countries are affected by bird flu:
Immunise Australia - www.immunise.health.gov.au
1 – In South Australia the law requires doctors and laboratories to report some infections or diseases to SA Health. These infections or diseases are commonly referred to as 'notifiable conditions'.