A strain of bird flu (H7N6) in Otago

Situation updates

Check our media releases for the latest information on the H7N6 detection in Otago.

Strict biosecurity measures in place on chicken farm (2 December)

Biosecurity controls in place after a strain of avian influenza detected

There continues to be no sign of high pathogenicity avian influenza (HPAI) outside of Mainland Poultry’s farm at Hillgrove, Otago, where the H7N6 strain of HPAI was detected in December 2024.

We remain confident that we are on track to stamp out H7N6, but there is still work to do.

While H7N6 is not the H5N1 strain circulating in wildlife around the world, we are taking the detection seriously and the farm remains under strict biosecurity lockdown.

There remains no risk to eggs and chicken supply in New Zealand given the size of the national flock, nor any issues for food safety. The risk to human health remains low.

What we are doing in response to this detection

We acted quickly to put strict biosecurity controls in place at the farm to prevent any possible spread. Those controls will remain in place until cleaning, decontamination and a standdown period have been completed.

All chickens on the farm were humanely culled.

Cleaning and thorough decontamination (disinfection) of the farm is being carried out to ensure all traces of the disease have been removed.

Ongoing testing and monitoring of chicken farms linked to the Hillgrove property are showing no signs of HPAI H7N6.

The response effort will continue.

What is HPAI H7N6 and how did it get here?

Avian influenza is a viral disease of birds found globally. Virus strains are described as low pathogenicity (LPAI) or high pathogenicity (HPAI).

The H7N6 strain is closely related to LPAI strains present in wild birds in New Zealand.

LPAI has been present in wild bird populations in New Zealand for over 20 years and many species of wild birds may have strains of the virus. Internationally, over 5,000 species of wild birds have this type of avian influenza.

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.

We have strong evidence that this is the cause of the infection at the Hillgrove farm and may have happened 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. This is the first time such an event in New Zealand has been documented, indicating that it is a very rare event for New Zealand.

There is no evidence that this strain of high pathogenicity H7N6 can spread from chickens back into wild birds.

While this is a high pathogenic strain, it is not the HPAI H5N1 strain that has caused deaths in poultry, wild birds, and mammals overseas. New Zealand remains free of HPAI H5N1.

Testing has confirmed the strain is unrelated to the H7 strain of avian influenza identified in Australia earlier this year.

What is the impact on international trade?

Immediately following the detection, we suspended certification of live and raw poultry commodities to markets requiring freedom from HPAI and have worked to protect as much of New Zealand’s existing trade as possible.

We continue to make positive progress in resuming safe trade. For example, we reached agreement with Australia to continue the export of some poultry products, including chicken meat, dried pet food, and dog rolls that meet avian influenza heat treatment requirements, worth more than $50 million.

We’re in close contact with relevant trade partners. While there are common elements across markets, solutions are agreed with each country.

How we have been preparing for the arrival of bird flu

Biosecurity New Zealand has been preparing for HPAI for some time. International experience with avian influenza has shown us this particular strain can be eradicated quickly and successfully.

We are working closely with industry partners. We have put a lot of effort in with the poultry and egg sector, the Department of Conservation, and Ministry of Health to prepare for H5N1 and that puts us in a good position to deal with the less virulent H7N6 strain found on this farm.

Eating eggs and poultry products is safe

There are no food safety concerns. Avian influenza viruses are sensitive to heat treatment, and cooked food is safe to eat.

There is no evidence that people can be infected with avian influenza by eating thoroughly cooked eggs or poultry (like chicken, turkey, or duck), or foods that contain them.

Eggs should be cooked until the white is completely firm, and the yolk begins to thicken.

Chicken needs to be cooked to an internal temperature of:

75°C for at least 30 seconds, or
70°C for 3 minutes, or
65°C for 15 minutes.

Does this mean New Zealand is at greater risk of getting H5N1?

The H7N6 strain detected in Otago is different from H5N1. The detection of H7N6 does not change the likelihood or risk of H5N1 arriving in New Zealand.

Biosecurity New Zealand and our partners have surveillance programmes in place to detect the arrival of the most concerning strain of H5N1 and other exotic diseases.

While the HPAI H5N1 strain is still some distance from New Zealand, it’s important we take a cautious approach.

New Zealand has an advantage over many other countries that have experienced the H5N1 strain of HPAI, in that we have time to prepare.

Are wild birds a risk to poultry farms?

There is no evidence to suggest any recent change in the circulating LPAI viruses in New Zealand wild birds or that the risk of spread of LPAI from wild birds to poultry has changed.

However, changes in animal husbandry with more free-range birds does create the potential for increasing exposure of poultry to LPAI viruses carried by wild birds.

Good on-farm biosecurity and minimising the contact between wild birds and poultry is the recommended approach to protecting poultry from bird flu.

Signs of HPAI

Look out for signs of HPAI in chickens, turkeys, and domesticated waterfowl such as ducks and geese.

Chickens and turkeys

The most obvious sign is sudden death of multiple birds within a flock. As well as sudden mortality, signs for HPAI can include:

lethargy or a reluctance to move
reduced appetite
swelling around the head and neck
droopy head, paralysis, or incoordination (neurological signs)
darkened or swollen face, discolouration of wattles and combs
coughing, panting, and nasal discharge
unexpected drop in egg production
bruising or haemorrhages, especially of the legs
watery or green diarrhoea
a silent or "too quiet" poultry shed.

Domesticated waterfowl, such as ducks and geese

HPAI generally has lower mortality in waterfowl, so it is harder to detect. Signs are usually related to the nervous system, such as involuntary movement, lack of coordination, blindness, and trembling.

How to report suspected HPAI

If you have 3 or more sick or dead poultry in a group, report it immediately to the exotic pest and disease hotline on 0800 80 99 66. Do not handle the birds.

Provide as much detail as you can, including:

a GPS reading or other precise location information
photographs or videos of sick and dead birds
species identity and estimate of numbers affected
note how many are sick or freshly dead, and the total number present.

We will take the details and an incursion investigator will be in contact with you. Follow any instructions from MPI for handling of sick or dead birds.