New Zealand's egg and chicken farmers are being urged to be vigilant and keep up strict biosecurity and surveillance measures in case avian influenza arrives in New Zealand.

Bird flu, the highly pathogenic H5N1 virus, was top of the agenda at the International Poultry Council's annual meeting in Argentina last week.

The virus has been circulating again, most recently in the United States, where it has been discovered in dairy cow herds and infected a dairy worker.

Michael Brooks, executive director of both the Poultry Industry Association of New Zealand and the Egg Producers' Federation New Zealand, was in Buenos Aires for the event.

He says the fact avian flu has not been found in Australia, New Zealand and the Pacific Islands makes us quite unique, but the risk is still there.

"We've looked at the migratory birds coming from the Northern Hemisphere and we've never found it in those birds."

He says the discovery of the virus in birds in Antarctica in October last year heightens the risk.

"It's now in Antarctica, and so potentially birds may contract it from Antarctica and come up to New Zealand through the sub-Antarctic Islands. Maybe not migratory patterns, birds blown off course or something. That's a new risk that we just hadn't expected."

And there are also fears about the impact its circulation could have on New Zealand's native wildlife if it arrived here.

Brooks said the Ministry for Primary Industries has been carrying out surveillance of wild birds for decades, and is ramping it up even more now.

He says the industry is working very closely with MPI, as the virus will have a serious impact on the commercial poultry sector if it were found here.

"We do not want it to be getting onto commercial farms. It really becomes a complex situation. So the number one thing is do what we can in terms of biosecurity.

"I think we've been lucky in New Zealand. We haven't had the risks. The risk is going to be incredibly increased and every possible step that we can take around biosecurity, ensuring little or no interaction with wild birds, protection of feed - all those sorts of things are really important."

Brooks says farmers should keep their tracing and biosecurity plans up to date, and keep wild birds off their property as much as possible.

Avian flu has caused the death of hundreds of millions of wild and commercial birds across Africa, Europe and Asia since it was first discovered in China in the mid-1990s.

-RNZ.