Avian Influenza (bird flu) in humans - including symptoms, treatment and prevention

Avian influenza (AI) viruses are common in wild birds and cause outbreaks in poultry. Infection of humans with AI viruses is uncommon.

Avian influenza in humans is a notifiable condition.

What is avian influenza?

Avian influenza, or bird flu, is caused by various strains of influenza A viruses.

Some strains cause no or mild disease in wild birds while others can cause severe disease in poultry (such as chickens). Certain strains can infect mammals including seals and livestock.

Occasionally AI viruses infect humans.

How avian influenza is spread?

Humans can be exposed to AI viruses through:

  • Direct contact with infected birds or other infected animals
  • Contact with environments, surfaces or objects contaminated by infected birds or other infected animals or their faeces or secretions
  • Breathing in dust contaminated by AI viruses

Higher risk activities include slaughter, defeathering, butchering, and preparation for cooking of infected birds and other infected animals.

AI viruses cannot be transmitted to humans through the consumption of properly cooked poultry meat or eggs.

Person-person transmission of AI viruses is rare but may occur after very close and prolonged contact with someone who has infection with AI virus.

Signs and symptoms

People infected with AI virus may have no or mild symptoms. When symptoms occur, they can be similar to seasonal influenza:

  • fever
  • cough
  • tiredness
  • muscle aches
  • sore throat
  • shortness of breath
  • runny nose
  • headache
  • diarrhoea

In addition, some people with AI infection develop conjunctivitis (red, sore, or watery eyes).

In severe cases there can be pneumonia, encephalitis (infection affecting the brain), and even death.

Diagnosis

Diagnosis may be confirmed by laboratory testing of a nose or throat swab, or sputum.

Conjunctival (eye) swabs may also be taken where there is conjunctivitis.

Tell your doctor if you have been in close contact with sick birds or animals or have travelled recently to a region with avian influenza.

Rapid antigen tests (RATs) for seasonal influenza should not be used to test for AI.

Incubation period

The incubation period (time between becoming infected and developing symptoms) will vary according to the specific strain of avian influenza and may range from one to ten days.

Infectious period

Uncertain. People are probably infectious to others from about the day before symptoms start until around 7 days after symptoms start.

Where people have weakened immune systems, they may remain infectious to others for prolonged periods.

Treatment

People with AI should be treated with antiviral therapy, starting as soon as possible, and ideally within 48 hours of symptoms starting.

Some people with AI will need treatment in hospital or intensive care. 

Prevention

The highest risk is through working with infected birds and other infected animals in regions where there is avian influenza.

  • Avoid poultry farms, and live bird or animal “wet” markets in regions with avian influenza.
  • Wash hands thoroughly with soap and water after touching uncooked poultry products.
  • Avoid touching your eyes, nose and mouth after touching uncooked poultry products.
  • Wash kitchen and cooking utensils thoroughly after handling raw poultry.
  • Ensure poultry and poultry products (such as eggs) are well-cooked before eating.
  • Persons who work with poultry or have contact with poultry should follow the personal protective equipment recommendations and other guidance on the Primary Industries and Regions website
  • Poultry workers and other persons in contact with poultry who develop symptoms compatible with AI should isolate themselves and seek medical advice. Tell the doctor you have contact with poultry and may have avian influenza. Wear a mask whilst near others.

Persons who have regular contact with poultry or other animals at risk of avian influenza are strongly recommended to have the seasonal flu vaccine each year. Although this will not protect against avian influenza, it will decrease the chance of getting seasonal flu and AI at the same time. If a person has seasonal flu and AI at the same time the viruses may share genetic material and produce a new flu which is able to spread between humans more easily.

Information and resources for health professionals