We need to be ready for bird flu
Avian influenza, also known as bird flu, is a highly contagious viral disease that mainly affects birds. However, it can also spread to mammals – including people.
There are 2 main types of avian influenza:
- high pathogenicity avian influenza (HPAI), which can cause severe signs and high death rates in birds. There are a number of strains including H5, H7, and H9
- low pathogenicity avian influenza (LPAI), which typically causes few or no signs in birds but can possibly mutate to HPAI.
LPAI is present in wild birds in New Zealand. We have an active surveillance programme for LPAI and test around 2,000 samples from wild birds each year. LPAI causes few or no signs of illness in wild birds. However, when a low pathogenicity strain of avian influenza is introduced to chickens, it can mutate into a high pathogenicity strain.
Strains of HPAI have circulated globally for years. Many countries have seasonal outbreaks in poultry every year.
New Zealand has been monitoring the spread of HPAI globally for the past 20 years. Biosecurity New Zealand and our partners have surveillance programmes in place to detect the arrival of HPAI and other exotic diseases.
Video – Learn more about bird flu (2.13)
This animated video explains how bird flu is spreading, symptoms to look out for, and biosecurity measures that people can take to be ready, just in case.
Transcript – show/hide
[This video uses animated graphics to illustrate the words. The first scene shows four wobbly, sick-looking birds (a gull, goose, gannet and chicken) with spiky spheres representing virus particles floating in the air.]
Narrator: “Bird flu is a serious virus that spreads easily between birds.”
Narrator: “The type of bird flu spreading overseas – HPAI H5N1 – can infect many kinds of birds and travel long distances.
[A globe-shaped world map shows virus particles over the upper part of the world. The words ‘HPAI H5N1’ appear on screen when the narrator says these words.]
Narrator: “It’s already killed millions of birds overseas, including wild birds, poultry, and pet birds.”
[The words ‘Bird flu has killed millions of birds overseas’ appear on screen, as well as the words ‘Wild birds’, ‘Poultry’, ‘Pet birds’ with circular portraits of birds above these words – a gannet, chicken and parrot are represented respectively. The circles expand slightly as each bird category is mentioned.]
Narrator: “We don’t have bird flu in New Zealand yet, but it could arrive through migrating wild birds.”
[A gull flies through a cloudy sky in a straight line surrounded by virus particles.]
Narrator: Here’s what to look out for – and how to be ready, just in case.
[A checklist pops up on screen, with the heading ‘What to look for’.]
[The words ‘How the virus spreads’ appear on screen in an orange text box, accompanied by music.]
Narrator: “Infected birds shed the virus in their saliva, nasal secretions and faeces.”
[A wobbly gull is surrounded by virus particles. The words ‘saliva’, ‘nasal secretions’ and ‘faeces’ appear on screen as these words are said, with dotted lines pointing to the relevant body part.]
Narrator: “Just one bird’s droppings can carry enough virus to infect thousands of others.”
[Screen zooms out to numerous identical gulls. The first gull’s dropping has an arrow pointing to it with the text ‘One dropping can infect thousands’.]
Narrator: “Once it’s in a flock, it can spread fast – sometimes in just a few days.”
[Six gulls surrounded by virus particles shown on screen. Two are lying upside down with their legs in the air and crosses for eyes to show they are dead.]
Narrator: “People can also spread the virus without knowing it – on their shoes, clothes, or shared gear.”
[A person is shown from the neck down, wearing a white t-shirt, black shorts and orange gumboots, holding a shovel upright. The words ‘shoes’, ‘clothes’ and ‘shared gear’ appear on screen as they are spoken, with black dotted lines pointing to each item, surrounded by virus particles.]
Narrator: “That’s why it’s important to clean up properly before and after handling birds.”
[Split screen depicting hand washing on the left and scrubbing the bottom of boots on the right.]
[The words ‘Impact on wild birds’ appear on screen in an orange text box, accompanied by music.]
Narrator: “We’re not sure how bird flu would affect our native birds.”
[Leafy foliage in foreground, a kiwi is in the bottom middle of the screen and a ruru (morepork) is on a branch, top right.]
Narrator: “But birds that nest in large groups – like gulls, gannets, and terns – could be most at risk.”
[Slide transition to a lineup of three birds – a gull, a gannet and a tern – with some green foliage in the foreground. The words ‘Birds that nest in large groups could be most at risk’ appear at the top. The words ‘Gulls’, ‘Gannets’ and ‘Terns’ appear under each image as they are named.]
[The words ‘Signs in birds’ appear on screen in an orange text box, accompanied by music.]
Narrator: “One of the first signs is several birds dying suddenly, with no clear reason.”
[Transition to three gulls surrounded by virus particles. The gull in the middle looks sick and has its head down. The gulls on either side of it are upside-down with their legs in the air and crosses for eyes to show they are dead. The words ‘Several birds dying suddenly’ appear at the top.]
Narrator: “Other signs – especially in ducks and geese – include being sleepy, wobbly, or unable to fly.”
[Transition to wobbly goose surrounded by virus particles. A line points to its head with the word ‘Sleepy’, then a line points to the front of its body with the word ‘Wobbly’ and then a line with the word ‘Unable to fly’ points to its wing as the narrator says these words.]
[The words ‘Report it’ appear on screen in an orange text box, accompanied by music.]
Narrator: “If you see three or more sick or dead wild birds together, call the exotic pest and disease hotline on 0800 80 99 66. Don’t touch or move the birds.”
[Two sick looking gulls and one upside-down dead gull surrounded by virus particles are on screen. There is a sign on the right depicting a hand with a diagonal line through it and the words ‘Don’t touch!’. The words ‘If you see three or more sick or dead wild birds together’ appear on screen towards the bottom. When the 0800 number is mentioned the words ‘Call 0800 80 99 66 appear on screen in an orange text box.]
Narrator: “If you keep poultry and notice signs of bird flu in several birds, talk to your vet first. They’ll help rule out other more common illnesses and tell you what to do next.”
[Slide transition to three wobbly chickens surrounded by virus particles. The white one in the middle is sitting on a nest. The words ‘If you keep poultry and notice signs of bird flu in several birds’ appear on screen. When the narrator says ‘Talk to your vet’ this text pops up on screen in an orange text box.]
Narrator: “Want to know more about bird flu signs and how to report them? Visit the Ministry for Primary Industries’ website www.mpi.govt.nz/bird-flu.”
[Orange bird flu branding – light orange background with a darker orange feather with the tagline ‘Bird Flu Be Ready’ – comes up on screen with the bird flu URL www.mpi.govt.nz/bird-flu and MPI and New Zealand Government logos.]
[Video ends. End of transcript.]
Bird flu (H7N6) in Otago in 2024
A strain of avian influenza, H7N6, was detected at an Otago egg farm in December 2024. We have strong evidence that the strain may have developed after free-range laying hens foraging outside were exposed to the low pathogenicity virus from wild waterfowl, which then mutated in the hens to become HPAI. While it is not the H5N1 type circulating among wildlife around the world that has caused concern, we have worked with the farm owner and industry to stamp out this strain of bird flu.
A strain of bird flu (H7N6) in Otago
Global spread of HPAI H5N1
In 2020, a new H5N1 strain – known as H5N1 2.3.4.4b – emerged in the northern hemisphere. It established in wild birds and spread to the United Kingdom, Europe, the United States, and other regions.
In 2023, it was detected in the southern hemisphere. Since then, it has spread through South America to the sub-Antarctic islands and the Antarctic peninsula.
The new H5N1 strain can infect a much broader range of wild birds and spread across a larger geographical range than previous strains have.
It can cause high numbers of deaths in poultry (chickens and turkeys), waterfowl (ducks, geese and swans), shorebirds (godwits, stilts and plovers) and seabirds (gulls and terns).
It has also spilled over to more than 60 species of mammal, including marine mammals, companion animals and livestock.
If this strain of HPAI arrived in New Zealand, it could spread by direct contact between infected and healthy birds, or through contamination of equipment and materials, including water and feed.
New Zealand and our neighbours remain free from HPAI H5N1
Our neighbours, including Australia and the Pacific Islands, remain free from H5N1 and the likelihood of it coming into New Zealand on pathways that we manage is low.
Unlike many biosecurity threats, H5N1 is not expected to be brought to New Zealand by human activity, but by migratory wild birds. For this reason, it is not likely that it could be kept out of New Zealand over the long-term or eradicated once it establishes in the wild bird population.
As more information emerges about how the disease affects wild bird species in the Southern Ocean, we’ll have a better understanding of the likelihood of it reaching New Zealand through migrating birds.
Risks to humans and animals
Human infection with HPAI of any strain is rare. It is usually only found in people who have had a lot of contact with infected birds or other infected animals.
So far, no human-to-human transmission has been reported.
Overseas, some mammals, including dairy cattle in the United States, have been infected after contact with infected birds. With supportive care, infected cattle generally recover in 2 to 3 weeks.
Avian influenza, food safety, and human health
Dairy and other livestock that may be affected by avian influenza
Understanding HPAI H5N1
MPI commissioned a series of technical reports to inform our planning for H5N1 clade 2.3.4.4b should it arrive here.
Summary of technical reports
HPAI H5N1 assessment of risk to New Zealand [PDF, 817 KB]
Detailed appendices
Avian influenza baseline threat assessment August 2024 [PDF, 757 KB]
Signs of HPAI
The most obvious sign of HPAI is sudden death in several birds. Other signs in birds can include:
- weakness and trembling
- paralysis
- breathing difficulties
- lack of coordination
- blindness
- diarrhoea.
Poultry may show more severe signs than wild birds, including lethargy, loss of appetite, droopy head, darkened or swollen comb/wattle, panting, nasal discharge, unusual drop in egg production, and bleeding disorders.
Commercial poultry flocks and avian influenza
Domestic poultry and birds and avian influenza
Reporting avian influenza
If you see 3 or more sick or dead wild birds in a group, report it immediately to the exotic pest and disease hotline on 0800 809 966. Do not handle or move the birds.
Provide as much detail as you can, including:
- a GPS reading or other precise location information
- photographs and videos of sick and dead birds
- species name and estimate of the numbers affected
- how many are sick or freshly dead, and the total number of birds present.
We will note the details and an incursion investigator will contact you.