Minister ‘pretty certain’ bird flu outbreak over, warns of further incursions

Biosecurity Minister Andrew Hoggard. Photo / RNZ

Biosecurity Minister Andrew Hoggard is cautiously optimistic that a bird flu outbreak at an Otago farm has been stamped out, but he warned a different strain of the flu was circulating globally and would likely arrive in New Zealand.

The outbreak was discovered in December requiring almost 160,000 hens infected with the flu to be culled. The virus did not spread beyond the single farm where it was discovered.

Hoggard said farms that were connected to the original outbreak had been tested and several incubation periods have passed without further cases being discovered.

“They’ve been testing all the farms that had traces with that farm and they have done two incubation periods. If that disease had migrated to another farm we would have expected to see it in that period.

“We’ve had two incubation periods and nothing has come up in that period on any other farms, so we’re pretty certain it’s stopped cold,” he said.

Hoggard said lime had been applied to the farm as a decontaminant.

The strain discovered in Otago was the H7N6 strain. New Zealand had not had an outbreak of that strain before, Hoggard said.

New Zealand is getting ready for a likely outbreak of another strain of the virus, H5N1, which has been spreading around the world since it emerged in 2020.

“Quite frankly everyone needs to start being prepared for that,” Hoggard said, describing an eventual outbreak in New Zealand as “probable”.

High pathogenicity avian influenza (HPAI) H5N1 is spread by wild birds, meaning it’s unlikely it can be kept out of New Zealand, and it’s unlikely to be eradicated once it establishes in the wild bird population.

If it arrives in New Zealand, it could quickly spread to other wildlife including rare and protected birds, or poultry by direct contact between infected and healthy birds, or through contaminated equipment and materials, including water and feed.

The flu is currently on the side of Antarctica furthest away from New Zealand, but Hoggard said that did not mean it would stay there.

“It’s entirely possible that it will cross to our side of Antarctica on migratory birds, go up to the Subantarctic islands and then across. We’ve got a couple of tripwires there that will give people some warning, but there’s nothing we can do to stop that from happening,” Hoggard said.

Thomas Coughlan is Deputy Political Editor and covers politics from Parliament. He has worked for the Herald since 2021 and has worked in the press gallery since 2018.