The H7N6 strain of high pathogenic avian influenza (HPAI) was discovered at Mainland Poultry’s Hillgrove Farm, near Moeraki in early December and resulted in a shutdown of the farm and culling of about 160,000 birds.
“While there is still work to be done, the lifting of movement controls is a significant milestone in the response and means that Mainland Poultry can begin the process of returning to business,” MPI chief veterinary officer Dr Mary Van Andel said.
“We’re grateful to Mainland Poultry, which did the right thing in notifying us as soon as an exotic disease was suspected and for working with us in partnership to successfully stamp out this disease.”
MPI immediately put strict movement controls on the property to prevent goods or anything else that might be carrying the virus leaving the property.
Dr van Andel said more than 5600 tests were carried out on samples from poultry and wild birds, including from 36 flocks across 5 farms linked to Mainland’s Hillgrove property.
HPAI was not found anywhere other than Hillgrove, giving confidence the disease had been contained and stamped out.
Dr Van Andel said chickens on the farm were humanely euthanised and disposed of in a secure landfill, along with eggs, litter and manure. This was followed by an extensive cleaning and disinfection process.
“The processes we have followed – depopulation and disposal, decontamination of the site and extensive surveillance – give us confidence that the virus has been eradicated.
MPI staff will continue to support Mainland as the farm is repopulated.
“Good progress is being made to restore trade, with around $300 million of trade in poultry products recovered to date.”
MPI said it had worked with overseas government counterparts and industry partners in New Zealand to meet market requirements and had also proposed alternative assurances to some markets.
Testing indicated that the infection at Hillgrove was likely to have occurred after free-range laying hens foraging outside were exposed to wild birds with a low pathogenicity (LPAI) virus strain, which then mutated in the hens to become HPAI, Dr Van Andel said.
“This is the first time such an event in New Zealand has been documented and our first case of HPAI. We’ve learned a lot from this response that will help us to prepare for HPAI H5N1 if it spreads here.”
