4 Dec 2024

Bird flu outbreak potentially wider than yet known - virologist

9:40 pm on 4 December 2024
University of Otago virologist Jemma Geoghegan.

Otago University virologist Jemma Geoghegan said bird flu spreads very easily, and there is a high risk of it being passed on. Photo: University of Otago

  • 80,000 birds to be culled at initial Moeraki farm where bird flu was discovered
  • Investigations are underway at a second Otago farm with sick birds
  • Second farm is not linked to the six other farms identified as being at risk

A leading virologist says she will not be surprised if the Otago bird flu outbreak continues to spread to other farms in the way it did in the devastating Victoria outbreak.

A second farm, south of Dunedin, is now under investigation for potential bird flu. And the Ministry for Primary Industries (MPI) has confirmed it is not one of six farms that were earlier identified as being at risk of infection.

MPI announced restrictions on the second farm - a small free range farm, on Wednesday, after being notified that chickens were showing signs of illness.

The H7N6 strain was first found at a farm near Moeraki, managed my Mainland Poultry, after testing from sick birds identified the virus.

The second farm, which has about 6000 birds, has been placed into isolation after birds started showing signs of infection, and some dying.

Testing and tracing is currently being carried out to see if it's connected to the outbreak at the Moeraki farm.

Otago University virologist Jemma Geoghegan said she was not surprised that the virus may have infected the second Dunedin farm.

"The virus we know spreads quite rapidly among chickens, and as we've seen elsewhere around the world, this virus is not usually contained just to the one farm, it really depends on those farming practices."

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She said the infection had the potential to be more widespread than had been identified so far.

"I wouldn't be surprised if this was a little bit more widespread than initially thought. This is the very same pattern that we've seen in Australia, for example, a few months ago, where one farm in in Victoria was identified to have the detection of this virus," Geoghegan said.

More than a million birds were killed in Australia to try to contain the spread of the virus there.

Ministry for Primary Industry chief veterinary officer Dr Mary van Andel said the farm south of Dunedin did not have obvious links to the farm in Moeraki where birds had tested positive.

''This is a farm that was notified and we're really grateful to people who do notify clinical signs that are different or abnormal in their in their livestock. We rely on that," she said.

"This is a separate farm, nothing to do with the business that's being investigated and that has been identified as having the case.

Van Andel said on Wednesday two other sheds on the Moeraki farm, which were being tested, were clear of signs of the virus - so far.

"This is a very infectious disease and you know we'd have to be very much focused on biosecurity between sheds to make sure that those stay uninfected."

Van Andel said the other six farms identified as being at risk were not showing signs of infection: "Those locations remain clinically normal.

"We will be doing sampling and testing on those locations, and the farmer is watching those production figures, like the number of eggs laid, and feed consumption, like a hawk."

Testing will continue for the next few weeks, as the incubation period for influenza is up to 21 days.

MPI will also be increasing its presence in Otago and has set up a regional control centre to manage the situation.

In a statement on Wednesday afternoon, Mainland Poultry chief executive John McKay said it was in "full response mode".

"Today we have begun the humane culling of birds in the two affected sheds at Hillgrove Farm. It is expected to take two to three days, using industry standard practice of CO2 containerised gas.

"This method is in line with the Code of Welfare. We will be taking every precaution to ensure the safe and secure disposal of chickens and waste materials from the affected sheds under the direction of the Ministry for Primary Industries (MPI)."

McKay said although necessary to stop the virus spreading, culling decisions were upsetting and it was a distressing situation for his team.

"As an industry, we have been preparing for this type of scenario for some time. Our proactive collaboration with MPI and the wider industry has allowed us to be ready and ensure swift action.

"Mainland Poultry remains committed to the welfare of its birds, the wellbeing of its staff and the responsible management of the situation. We will be doing everything in our power to eradicate the virus."

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