Avian influenza (AI): Questions and answers
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;
- respiratory signs of coughing, sneezing or rasping breathing
- rapid drop in feed intake, water intake and egg production
- typical “sick bird” signs – ruffled feathers, depression, closed eyes
- 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.
The strain detected in NSW is HPAI H7N8. It is not the same as the H5N1 strain that is impacting domestic and wild animals and causing concern globally. The NSW cases are not connected to the H7N3 and H7N9 strains of HPAI in the Victorian outbreak.
Yes. There have been a number of outbreaks of avian influenza in domestic poultry since 1976 in Victoria, Queensland and NSW. The most recent outbreak in NSW was in Young in 2013. 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. Low pathogenicity avian influenza naturally cycles through wild bird populations with little impact. It is important to prevent outbreaks in commercial poultry farms because this is where the virus can mutate to become the high pathogenicity form of the virus. It is essential to minimise possible contacts between domestic and wild birds to prevent viral introduction.
No. Poultry products (meat and eggs) that have been properly 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.
The majority of birds are susceptible to avian influenza and pet birds are no exception. All bird owners are encouraged to be aware of the signs of avian influenza and to report all unusual signs of disease or death to their veterinarian, or the Emergency Animal Disease Hotline on 1800 675 888.
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.
