What is avian influenza?

Avian influenza is used to describe all of the influenza viruses that can infect birds - this includes both wild birds such as ducks and domestic birds such as chickens. It now appears that birds are a natural reservoir of flu viruses - to date 15 strains of influenza A virus are known to exist in bird populations.

Many forms of the avian influenza virus cause only very mild symptoms in birds, or no symptoms at all. However, some strains of the influenza A virus can produce a highly contagious and rapidly fatal disease. These very virulent strains of the virus are known as "highly pathogenic avian influenza". It's these viruses that cause particular concern. One such avian influenza virus is currently infecting chickens in the Asian region, this particular strain is known as H5N1.

Should the H5N1 strain adapt and spread via humans we could very quickly be in a worldwide pandemic. This is because currently humans do not have a natural immunity or protection from this strain of avian influenza.

In history there have been several outbreaks of bird flu viruses which have been controlled by quarantining or destroying thousands of birds to stem the spread of the virus between countries.

Bird avian influenza symptoms

Infected birds shed flu virus in their saliva, nasal secretions, and feces. Susceptible birds become infected when they have contact with contaminated excretions or surfaces that are contaminated with excretions.

Symptoms in birds show themselves as some or all of the following; a decrease in bird activity (lethargy), a drop in egg production, a swelling of the head, breathing problems, diarrhoea, muscle paralysis and sudden death.

Human avian influenza symptoms

In humans, avian influenza shows itself as similar symptoms to other types of influenza, such as fever, sore throat, cough, headache, lethargy, muscle ache, and conjunctivitis. Cases of bird flu are more likely to cause breathing problems and pneumonia that may be fatal.

The state of the infected person's immune system will also play a major part in the severity of the infection.

If you at any time suspect you may have an avian influenza infection you should contact a medical professional to confirm.