Avian influenza (aka bird flu, avian flu) is caused by a type of influenza virus that is hosted by birds, but may infect several species of mammals. It was first identified in Italy in the early 1900s and is now known to exist worldwide. A strain of the H5N1-type of avian influenza virus that emerged in 1997 has been identified as the most likely source of a future influenza pandemic.
Strains of avian influenza virus may infect various types of animals, including birds, pigs, horses, seals, whales and humans. However, wild fowl act as natural asymptomatic carriers, spreading it to more susceptible domestic stocks. Avian influenza virus spreads in the air and in manure and there is no evidence that the virus can survive in well cooked meat.

Diagnosis How to Recognise Avian Influenza

• Ruffled feathers
• Soft-shelled eggs
• Depression and droopiness
• Sudden drop in egg production
• Loss of appetite
• Cyanosis (purplish-blue coloring) of wattles and comb
• Edema and swelling of head, eyelids, comb, wattles, and hocks
• Green diarrhoea
• Blood-tinged discharge from nostrils
• Incoordination, including loss of ability to walk and stand
• Pin-point hemorrhages (most easily seen on the feet and shanks)
• Respiratory distress
• Increased death losses in a flock
• Sudden death
• Nasal discharges

For more detail in avian influenza in poultry click here

Poultry Vaccination as a strategy for controlling AI in commercial birds Outbreaks of avian influenza in the poultry industry cause devastating economic losses and is generally controlled through extensive culling of infected birds. Alternative strategies also use vaccination as a supplementary control measure during avian influenza outbreaks.

• Vaccination reduces susceptibility to infection.
• A higher dose of virus is necessary to infect the vaccinated birds.
• Vaccinated birds shed less virus.
  - Decreased contamination of the environment.
  - Decreased risk of human infection
• Used strategically vaccination compliments a stamping out strategy by slowing/stopping the spread of the virus

• www.avian-influenza.com
• Vaccination as Part of an Avian Influenza Control Strategy
• The use of vaccination as an option for the control of avian influenza (pdf)

BiosecurityAvian Influenza (Fowl Plague) is a potentially devastating disease, predominantly of chickens and turkeys, although the virus can also affect game birds (pheasants, partridge and quail), ratites (ostrich and emu), psittacine and passerine birds.
Avian Influenza is caused by an orthomyxovirus, or influenza virus and can survive for considerable lengths of time outside of the host and birds are infected through contact with other birds, mechanical vectors such as vehicles and equipment and personnel travelling between farms, markets and abattoirs.
Precautionary requirements include cleaning and disinfection of premises and the establishment of a Biosecurity barrier to help prevent spread of disease is essential.

• Avian / Bird Flu Disinfection
• Avian / Bird Flu Biosecurity

Useful Links

• OIE - HPAI Situation Reports
• Avian Influenza WHO information
• Avian Influenza CDC information
• Bird flu timelines Recombinetics
• The Rise of Avian Influenza in Asia
• About Highly Pathogenic Avian Influenza