New Zealand has ceased all poultry exports from its commercial rural Otago egg farm, after tests confirmed a “high pathogenic” strain of avian influenza in chickens. Notably, the viral strain differs from those responsible for the recent H5N1 (US) and H7 outbreaks in the US and Australia, respectively, confirms Biosecurity New Zealand. 

The move is expected to halt the exports of poultry products worth about NZ$190 million (US$112 million) a year until the country announces it is free of bird flu, according to Food Safety Minister Andrew Hoggard.

Tests from the Mainland Poultry managed farm identified the bird flu strain as the H7N6 subtype of avian influenza, which is closely related to low pathogenicity (HPA1) strains present in wild birds in the country.

The outbreak may be a “spillover event,” wher laying hens who were foraging outside of the shed were exposed to a low pathogenic virus from wild waterfowl,” explains Stuart Anderson, deputy director-general of Biosecurity New Zealand.

“Low pathogenic viruses are present in wild birds here, especially waterfowl like ducks, geese, and swans, and the virus can mutate on interaction with chickens.”

Amid ongoing human transmission concerns in other bird flu cases, especially farmers, Anderson assures that the strain found on the New Zealand farm is “not a wildlife-adapted strain like H5N1, so we believe it is unlikely to be transmitted to mammals.”

Ensuring food safety

According to Biosecurity New Zealand, there are no reports of ill or dead birds on other poultry farms and “no human health or food safety concerns.”

It suggests consuming “thoroughly cooked” egg and poultry products by heating food to an internal temperature of 75°C for at least 30 seconds, or 70°C for three minutes or 65°C for 15 minutes.

Government action

The government is taking “quick action” along with Mainland Poultry and has issued a restricted place notice.

“Test results late last night confirmed the strain, but we already had restrictions in place and expert biosecurity staff on site, with more arriving today.  Mainland Poultry took the right steps by reporting ill birds in one shed on the property and locking that building down as testing continued,” says Anderdon.

Biosecurity New Zealand has placed a 10 km buffer zone around the farm, with restrictions preventing animal movement, equipment and feed movement.

John McKay, chief executive of Mainland Poultry, which manages the free-range farm, says international experience with avian influenza has proven that H7N6 can be eradicated “quickly and successfully.”

“We will be working closely with MPI (Ministry for Primary Industries) to depopulate the affected shed, ensure rigorous testing of all other birds on the farm and manage the situation effectively.”

The farm has strong biosecurity standards and Mainland is helping the MPI with ongoing investigation and tracing animal movements. It suggests farmers to contact a veterinarian if they notice poultry or domestic birds exhibiting signs of HPAI, to rule out more common avian diseases.