A brown skua seabird was found dead on Petone Beach in Wellington, and testing yesterday confirmed it was positive for H5N1 bird flu.
University of Otago evolutionary virologist Prof Jemma Geoghegan said individual birds infected with the virus had been turning up across Australia in recent weeks, and it was only a matter of time before the virus arrived in New Zealand.
‘‘We were kind of expecting this any day now.
‘‘So the fact that it has arrived is ... confirming our suspicions that we’re not as geographically isolated as we might have thought.’’
H5N1 emerged about five years ago and has spread around the world.
About two years ago, a different virus hit an Otago egg farm, and all the poultry were culled to stop it spreading.
‘‘We’ve seen outbreaks of this type of virus before, but it’s always been contained because it’s only really been causing disease and spreading among poultry, and they can be quite contained.
‘‘The difference about H5N1 is that this strain of the virus has gained the ability to infect a really broad host range, and therefore expand its geographical range by not only infecting migrating sea birds, but also mammals as well.
‘‘We’ve seen it cause mass mortality events among animals.’’
It had also spread to dairy cattle across the United States and Canada, and as a result it had spilled over into humans, Prof Geoghegan said.
‘‘So if it’s poultry workers or dairy farm workers, or even people handling infected wildlife, they can be infected.
‘‘It does have quite a high mortality rate. It can be up to about 50% in humans.
‘‘But at the moment, the case numbers are quite small in humans because there’s no evidence that the virus transmits between humans.
‘‘Obviously, viruses evolve and that situation might change.’’
At this stage, it had the potential to be ‘‘catastrophic’’ for New Zealand’s poultry industry.
‘‘If it’s endemically spreading in wild birds in New Zealand, and it gets into poultry, it could be really catastrophic for that industry because we’ve seen across other countries massive amounts of culling once the virus has infected their flocks.’’
However, it was not yet known if it would also affect New Zealand’s dairy industry.
It was unlikely humans would be infected with the virus by eating chicken or eggs, she said.
‘‘We’re not really clear on whether or not that is a likely vector because usually the chickens get severely affected by this virus, and so they’re usually unable to lay eggs and they get culled or die of the virus way before they become consumed.’’
Another major concern was the virus’ impact on native birds.
‘‘A lot of our native birds are endemic and already struggling with other factors, such as climate change, disease and predation.
‘‘So that’s potentially why the Department of Conservation has been looking into vaccination for a limited number of species and individuals as well.’’
Biosecurity Minister Andrew Hoggard reaffirmed H5N1 bird flu was ‘‘a low health risk’’ to the public.
‘‘It rarely affects humans unless there is direct, close and prolonged contact with large numbers of sick birds.
‘‘Eggs and poultry remain safe to eat.’’
At this stage, only one seabird had been found and there was no evidence of any mass mortality in wildlife or transmission between wild birds in New Zealand.
There had also been no detection in poultry, but the situation was being closely monitored.
‘‘We ask the community to be alert and follow advice about reporting sick or dead birds.
‘‘It is vital that people do not touch or handle unwell birds.
‘‘The Ministry for Primary Industries [MPI] will continue its wider surveillance and work closely with industry, veterinarians and wildlife carers.’’
New Zealand was well prepared to respond to the virus and would work to protect poultry production and reduce impacts on wildlife and communities.
The MPI is testing birds every few days through reports and targeted wildlife surveillance.
