The clinical signs are extremely variable depending on many factors such as the type of bird, the virus subtype and the presence of other diseases. Infected birds may die shortly after acquiring the infection with no obvious signs or they may show a variety of symptoms including breathing difficulties, coughing, swollen head, dark comb and wattles, depression, drop in egg production, changes in egg shell colour, loss of appetite, decreased feed intake and decreased vocalisation. Nervous signs like tremors of the head, unsteady gait, twisted necks and other unusual positions of the head and body sometimes occur. These clinical signs are not specific to avian influenza and can be seen in other poultry diseases.
Avian influenza (AI) can be spread by movements of infected birds (domestic or wild), through droppings and secretions of infected birds directly or through movement of contaminated objects, clothing or vehicles. Windborne spread from infected large flocks is also possible over short distances. Other animals like cats and dogs can also spread the AI virus if they come in direct contact with contaminated materials or infected birds.
Most AI viruses cause only mild disease in poultry and are called low pathogenic avian influenza (LPAI) viruses.
Highly pathogenic avian influenza (HPAI) viruses can develop from certain LPAI viruses, usually while they are circulating in poultry flocks. HPAI viruses can kill up to 90-100% of the flock, and cause epidemics that may spread rapidly, devastate the poultry industry, and result in severe trade restrictions.
Yes. Some subtypes of the avian influenza virus (AIV) that are not known to cause disease have occasionally been found in wild birds and therefore it is very likely that these subtypes are continuously circulating among some populations of wild birds in Australia.
The National Avian Influenza Wild Bird (NAIWB) Surveillance Program conducts both targeted and general surveillance of wild birds for AI viruses in Australia.
To date, no highly pathogenic AIVs have been identified in Australian wild birds. However, targeted surveillance activities continue to result in evidence of a wide range of subtypes of AI viruses of low pathogenicity. Almost all AIV subtypes have been detected, including LPAI H5 and H7 subtypes, in wild birds in Australia.
Yes. There have been a number of outbreaks of avian influenza in domestic poultry since 1976 in Victoria, Queensland and NSW. All outbreaks were contained and successfully eradicated.
The level of biosecurity has been upgraded on commercial poultry farms in NSW to minimise the risk of exposure to risk factors like wild birds, contaminated water supplies, other animals and visitors. The poultry industry in NSW has been closely cooperating with NSW DPI to develop early reporting systems for unusual mortalities. NSW has extensive animal disease surveillance programs that ensure early detection of diseases. A network of private veterinarians, district veterinarians and diagnostic laboratories across NSW enable early diagnosis and effective response if an outbreak occurs.
No. The control of avian influenza in wild birds is not feasible. It is important to prevent outbreaks in commercial poultry farms because these birds could multiply the virus dramatically and the virus could spread further. It is essential to minimise possible contacts between domestic and wild birds.
An avian influenza vaccine is not commercially available in Australia.
No. Poultry products (meat and eggs) that have been property cooked are safe for human consumption as the cooking process destroys the avian influenza virus. Nevertheless, it is prudent for consumers to take normal food safety precautions when preparing and cooking poultry products.
Further information on food safety is available at the NSW Food Authority.
Yes. The majority of birds are susceptible to avian influenza and pet birds are no exception.
Basic biosecurity steps will minimise the risk of avian influenza as well as other diseases. Health monitoring and sound husbandry practices assist in early detection of any flock problems. Purchase birds from reputable sources. Where possible, minimise contact between domestic and wild birds or other animals. Minimise non-essential visitors contact with domestic and aviary birds. Keep new flock introductions separately for 2-3 weeks after arrival. Water supply in most backyard or aviary flocks is chlorinated town water. Water from a dam, river or creek should be chlorinated to make it safe to drink.