All bird flu cases likely not detected yet, expert says

A virologist says it's likely not all cases of the bird flu H5 strain have been detected in New Zealand.

By Sammy Carter and Pretoria Gordon of RNZ

A second case of the flu was found on Friday in a native kāhu, near Carteron in Wairarapa, and taken to Palmerston North Hospital.

Otago University professor Jemma Geoghegan said the first two birds are both solitary scavengers, who likely caught the virus by eating infected dead birds.

"It probably suggest that we haven't detected all the cases that are in New Zealand."

The first confirmed case was a brown skua found on Petone Beach in Wellington, which has since been put down.

Geoghegan said the source of the virus is likely closer than we might think.

However, finding the source would be very difficult, Geoghegan said, as it could be remote.

"It might be that we never know the actual source."

Instead, Geoghegan said the focus should be on detecting new cases early, and understanding how the virus is spreading.

Geoghegan works with the Department of Conversation to better understand how viruses transmit.

Ministry for Primary Industries staff in the Wairarapa were carrying out enhanced surveillance, as well as assessing reports of unwell or dead birds from the public.

There have been no further detections of the H5 strain on Saturday, after it was confirmed in a kāhu near Carterton on Friday.

Ministry chief veterinary officer Dr Mary van Andel said it received about 30 reports overnight.

"Some of these are repeat calls about birds we've already seen, some of them are, you know, a sparrow flew into the glass, but there will be a couple that do need to be tested."

Van Andel said staff considered every notification and triaged any suspected cases.

Cases were prioritised based on risk, van Andel added, as the strain can only be diagnosed through laboratory testing.

Investigators assess the type of species involved, the number of unwell or dead birds, their location, and the likelihood of disease risk.

Van Andel urged people to continue to report any sightings to the exotic pest and disease hotline.

"We have been expecting this strain of bird flu to arrive here in New Zealand. This isn't unexpected.

"What we need people to do now is focus on how to identify it, and what to do next."

Van Andel said birds could be unwell for a variety of reasons, including botulism, storm wreck, and other diseases endemic to New Zealand. In some cases, symptoms could be similar to bird flu, she added.