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.

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.