Biosecurity New Zealand says it is responding to a possible detection of a poultry virus, Infectious Bursal Disease Virus type 1, in a layer egg farm in Otago.
No birds at the Mainland Poultry farm in Waikouaiti have disease symptoms and the farm itself is under voluntary biosecurity controls as a precautionary measure, said Biosecurity New Zealand response manager David Yard.
Preliminary test results indicate the virus was highly likely to be present on the Mainland Poultry property, but further testing overseas was required to confirm this. Those results are expected around mid-September.
In addition, a second Mainland property, near the Waikouaiti facility, had returned suspect results. These are in the early stages of the confirmation process.
Departmental chief scientist Dr John Roche said the virus can affect the immune system of young chickens but it poses no risk to human health or the health of other animals.
"There is no food safety risk with this virus and people should have no concern eating chicken meat or eggs. There will be no impact on domestic egg and chicken meat supply," said Roche.
Yard said that while Biosecurity New Zealand was waiting for final confirmation from the overseas laboratory, it would stop issuing certificates for the export of chicken products to countries that require a guarantee that New Zealand is IBDV type 1-free.
That involved the trade in poultry meat and poultry products to four countries, with Australia being the largest importer of New Zealand chicken meat.
Biosecurity New Zealand said it was now working with the egg and poultry industries to understand, if confirmed as positive, the scale of the situation and what control or eradication measures were available.
Yard said while this work was underway, Biosecurity New Zealand was reviewing operational measures at the farm to assess, if confirmed present, the risk of spread to other sites.
Testing of other South Island layer and meat chicken farms was underway.
Biosecurity New Zealand said it will work with industry to consider options to manage the situation, balancing the impacts of the disease if confirmed, against the costs and benefits of any control measures.
There are two different types of IBDV – Types 1 and 2.
Type 2 is already in New Zealand and causes no significant health issues in the national flock and is of no trade concern. The current suspect result is for Type 1.
IBDV type 1 was discovered in New Zealand in 1993. An industry-led programme to eradicate has meant New Zealand has been able to claim absence of the disease.
Most other countries in the world have this virus and successfully manage it within the industry Biosecurity New Zealand said in a statement.
If the presence of IBDV type 1 is confirmed, Biosecurity New Zealand investigators will look at how the virus could have entered New Zealand, along with a range of possibilities including imported veterinary medicines, travelling farm workers, and other imported goods.