Photo: Cosmo Kentish-Barnes
The team of scientists at New Zealand's most biosecure facility have tested about 1000 samples from a chicken farm where bird flu was detected last week.
An outbreak of the highly pathogenic H7N6 virus in two sheds of a farm in Otago, managed by Mainland Poultry, has led to the cull of nearly 80,000 hens.
A second farm south of Dunedin was also under investigation after some chickens were found sick and dying, but test results were negative for bird flu.
The Ministry for Primary Industries' rigorous testing of the Mainland Poultry farm and the company's five other sites would continue for weeks, because it could take up to 21 days for birds to develop symptoms, chief veterinary officer Dr Mary van Andel told RNZ.
Swabs were taken from the birds' respiratory tracts - or organs, for post-mortem samples - and sent to the ministry's biocontainment laboratory at Wallaceville in Wellington for testing, she said.
The laboratory is the only facility of its kind in New Zealand, and is completely biosecure.
- Read more: What you need to know about bird flu
Staff at the lab were working their way through hundreds of samples at a time, but it was a lengthy process, van Andel said.
"Analysing them isn't just a kind of yes or no answer, it's a process, and we have to get that right, those results have to be accurate," she said.
Scientists tested for influenza A viruses and the H7 subtype, and carried out whole genome sequencing of the virus, which was compared with other genomes stored in databases, she said.
"So it's a really complex process to get the information that's required to have the epidemiological analysis and information that we need to be in control of this situation."
The conditions were trying for the scientists completing the testing, van Andel said.
"They're working in physical containment, so these are not easy circumstances to work under.
"It has particular ventilation systems, it's got air locks, it's got shower in, shower out, so it's an extremely complex and sophisticated facility."
The $87m facility was opened in 2021. It was designed to provide a safe environment for diagnostics, work with exotic diseases, biosecurity research and supporting the health ministry with human diseases, the MPI website said.
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