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HPAI causes severe symptoms and often death in birds
Avian influenza (AI) is a contagious viral disease that can affect both domestic and wild birds. There are a wide variety of AI viruses with different severities depending on the bird species infected and the virus strain. The two AI categories are:
- high pathogenicity avian influenza (HPAI) viruses, which cause severe symptoms and high mortality rates
- low pathogenicity avian influenza (LPAI) virus, which causes little or no symptoms.
Types of HPAI viruses like H5 and H7 cause high mortality in poultry (chickens and turkeys), and waterfowl (ducks, geese, and swans).
There have been outbreaks of HPAI in domestic and wild birds across the Northern Hemisphere.
New Zealand has never had HPAI, but LPAI viruses have been found in wild non-migratory ducks in the past.
AI is a zoonotic disease, which means there is the possibility it can spread between animals and to people. HPAI has been detected overseas in a variety of non-avian species, such as pigs, dogs, mustelids, and other mammals.
There are rare cases of human infection with avian influenza when people have a lot of contact with infected birds. You can find out more on the Ministry of Health and World Health Organisation websites.
Highly pathogenic avian influenza – Ministry of Health
Avian influenza – World Organisation for Animal Health
New Zealand's risk of HPAI arriving
New Zealand’s risk for HPAI is low and the situation is being monitored. New Zealand is low risk because it:
- is isolated from other land masses
- does not have migratory waterfowl pathways
- has strong border biosecurity.
How it might get to NZ
Avian influenza is mainly spread through migrating birds and by direct contact between infected and healthy birds. It can also be spread through contaminated equipment or materials (including water and feed).
HPAI is usually seen in poultry. It can also be transmitted by and affect wild birds.
Wild waterfowl, shorebirds, and seabirds can be hosts for bird flu viruses, although waterfowl are the most common. Because their habitats often border each other, it increases the risk of passing viruses to another species that may get sick from a particular variant.
Why the risk is low for the virus to arrive with migratory birds
- New Zealand is not on a migratory pathway of waterfowl. Stray waterfowl sometimes arrive from Australia, but it rarely happens.
- A variety of migratory shorebirds and seabirds travel a long distance to return to New Zealand each spring. But due to the high mortality of HPAI, the risk for live infected species making the journey to arrive here is low.
Surveillance and early detection
New Zealand has many systems in place to ensure early detection if HPAI were to arrive.
These include:
- reporting to the Biosecurity New Zealand Exotic Pests and Disease Hotline: 0800 80 99 66
- annual summer field surveillance programmes at non-migratory waterfowl sites with Fish & Game New Zealand
- monitoring and awareness with New Zealand's wildlife hospitals, poultry industry body veterinarians, and wildlife rehabilitation centres
- surveillance support and inputs from New Zealand's Wildlife Advisory Group
- working closely with the Department of Conservation Te Papa Atawhai (DOC) on any suspected exotic diseases in wild bird populations in Aotearoa, including native birds.
If HPAI was detected, Biosecurity New Zealand is the lead agency and will coordinate any response. Any actions such as movement control, vaccination or culling, would depend on the infected species and location.
Avian influenza and other wildlife diseases – DOC
How to identify HPAI
Avian influenza signs vary but with HPAI, the most obvious sign is several dead birds. As well as sudden mortality, symptoms for HPAI in poultry can include:
- lethargy or a reluctance to move
- reduced appetite
- droopy head
- darkened or swollen comb or wattle
- panting and nasal secretions
- unusual drop in egg production
- bleeding disorders
- a silent poultry shed.
In waterfowl, HPAI is generally less severe and slower to progress. Signs can include involuntary movement, lack of co-ordination, blindness, and trembling.
Symptoms in other species differ depending on the virus strain but could be similar.
What to do if you think you have found cases of avian influenza
If a significant number of birds are observed in a group sick or dying, report it immediately to Biosecurity New Zealand's Exotic Pest and Disease hotline on 0800 80 99 66.
Information that can be helpful for our investigators include:
- an accurate location of the birds (GPS reading or other precise location information is ideal)
- photographs or videos of sick and dead birds
- estimates of numbers affected and the possible species
- how many sick or freshly dead are present.
Make sure you wait for instructions before handling any sick or dead birds.
Avian influenza can only be diagnosed and confirmed through laboratory testing. If your backyard poultry are showing symptoms, contact your veterinarian first to rule out more common diseases.
HPAI in backyard poultry and waterfowl fact sheet [PDF, 521 KB]
