Highly pathogenic bird flu has reached New Zealand’s shores. What does this mean for the country’s birds — and people?
Chickens at a commercial egg farm in Otago have tested positive for the high pathogenic strain of avian influenza known as H7N6.
Around 80,000 birds will be culled at Hillgrove Egg Farm over the next two to three days after further testing revealed the virus had spread to a second barn at the facility.
1News answers eight questions about the situation.
Is this the same bird flu that’s had the rest of the world in a flap?
No.
While H7N6 is a high pathogenic strain of bird flu, it is not the H5N1 strain that has been killing poultry, wild birds, and mammals in other parts of the world.
How did the H7N6 strain reach this farm in Otago?
Director-General of MPI Ray Smith said the virus had been detected at another barn on the property. (Source: Breakfast)
Experts believe the outbreak in Otago may have started as a less deadly type of bird flu that mutated while spreading between laying hens who were foraging outside one of the farm sheds.
The H7 subtype of avian influenza is usually low pathogenic and found in wild birds without causing disease, University of Otago virologist Professor Jemma Geoghegan said.
“On some rare occasions, these viruses can spillover to poultry and evolve to become high pathogenic where they cause severe disease,” she said.
“This is what we saw happen in Australia a few months ago too. With chicken farms in such close proximity to wildlife, these sorts of spillovers are always a risk.”
The strain found in Otago is unrelated to the one that was identified in Australia earlier this year.
Is there any danger to public health from this outbreak?
Geoghegan said the H7 subtype has infected humans before, however it doesn’t spread between them easily.
“So, this is low risk for public health,” she said.
There are also no food safety concerns.
Viruses can’t withstand cooking temperatures, so thoroughly cooked poultry products, including eggs, are safe to eat, said Ministry for Primary Industries (MPI) Director-General Ray Smith.
“Just – as we always say – with poultry products, you need to cook them and that’s the way that you make sure that you don’t pick up anything unexpected,” he said.
Is there any danger to NZ’s wildlife from this outbreak?
There has been no evidence overseas of this strain moving back from poultry into wildlife, Minister for Biosecurity Andrew Hoggard said yesterday.
“So, we do not have to worry about a spread back to wildlife,” he said.
How does this affect NZ’s poultry industry?
Hoggard said concerns about spread were around gear moving from the affected Otago property to other facilities, which authorities were tracing. The incubation period for H7N6 is around seven to 21 days.
New Zealand has suspended all poultry exports while authorities move to contain the spread of H7N6.
MPI said the outbreak will have no major impact on egg supplies in the present circumstances.
Does this outbreak make NZ more vulnerable to the H5N1 strain?
The Ministry of Primary Industries says bird owners to take steps to protect their pets. (Source: 1News)
The discovery of the H7N6 strain of bird flu does not affect the chances of H5N1 being detected in New Zealand, MPI said.
However, last month, the Government urged New Zealanders who owned or kept birds to take steps to be ready for any arrival of high pathogen bird flu.
Members of the public should also report any sightings of three or more sick or dead wild birds in a group.
They can do this by calling the exotic pest and disease hotline (0800 80 99 66). MPI said people should provide as much detail as possible when reporting any sightings, including GPS coordinates, and photos or videos of the sick or dead birds. Members of the public shouldn’t handle the affected birds themselves.
What is happening with H5N1 in other parts of the world?
The spread of H5N1 in mammals in other parts of the world has been of particular concern this year.
Bird flu was detected in cows for the first time in March and has since become a multi-state outbreak in the US. It was also detected in a pig on a farm in Oregon in October.
These were concerning developments, because it means bird flu is evolving and changing its genetic code, Geoghegan said earlier this year.
“Before, [the virus] was quite confined to its host range and now the genetic mutations have allowed it to broaden that host range to a whole bunch of different bird species, but it’s also spilled over to mammalian hosts as well,” she said.
“Every time [the virus] transmits in mammals, it is under quite strong selection pressure to then be better at transmitting between mammals,” she said.
“These mammals act as a sort of mixing vessel so that influenza viruses can swap genetic material … and become better at spreading between mammals.”
So the H5N1 strain could be a danger to our wildlife?
Yes, Geoghegan also said the biggest danger bird flu currently presents to New Zealand is to its wildlife.
This is why the Department of Conservation (DOC) has been trialling a vaccine for some threatened native species, such as the takahē and kākāpō.
“New Zealand has a lot of native birds that are only found in New Zealand, and they’re really treasured taonga species that need to be protected,” Geoghegan said.
“That’s kind of the biggest threat to New Zealand. [Bird flu] is a public health [concern] but it’s way more of a problem for wildlife at the moment.”
