Biosecurity New Zealand is responding to a possible detection of a poultry virus, Infectious Bursal Disease virus (IBDv) type 1 in a layer egg farm in Otago and one other nearby property.

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, Biosecurity New Zealand response manager David Yard said in a press release from the agency.

Preliminary test results indicate the virus is highly likely to be present on the Mainland Poultry property, but further testing overseas is required to confirm this. Those results are expected around mid-September.

In addition, a second Mainland property, near the Waikouaiti facility, has returned suspect results. These are in the early stages of the confirmation process, the agency stated.

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.

Yard said that while Biosecurity New Zealand awaits final confirmation from the overseas laboratory, it would stop issuing certificates for the export of chicken products to countries that require a guarantee freedom from IBDv type 1. That involves the trade in poultry meat and poultry products to 4 countries, with Australia being the largest importer of New Zealand chicken meat.

Biosecurity New Zealand is 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 are available.

Yard said while this work is underway, Biosecurity New Zealand is 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 is underway.

Biosecurity New Zealand and industry will work together 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 program 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.

If the presence of IBDv type 1 is confirmed, Biosecurity New Zealand investigators will be looking at how the virus could have entered New Zealand and are looking at a range of possibilities including imported veterinary medicines, travelling farm workers, and other imported goods.