How NZ may reduce the impact when bird flu lands
Friday, 27 September 2024
Dr Mary van Andel is the Ministry for Primary Industries’ chief veterinary officer.
OPINION: Tough choices will be required to reduce the impact of bird flu when it arrives in New Zealand - to protect native species, and the commercial chicken and egg industries.
New Zealand has never had a case of high pathogenicity avian influenza (HPAI), but we are monitoring the HN51 strain’s spread and preparing in case it arrives here, with the aim of reducing bird flu’s impact.
The HN51 strain, which started circulating in 2020, is different from other strains of HPAI, such as the H7 and H9 types detected in Australia this year. Unlike those strains, it has adapted and can be spread by a much wider range of host species.
Overseas HN51 has caused high numbers of deaths in poultry (chickens and turkeys), waterfowl (ducks, geese and swans), shorebirds (godwits, stilts and plovers) and seabirds (gulls and terns). Mortality is particularly high in chickens – between 95% and 100%.
We know HPAI is likely to affect our native species and has the potential to significantly affect our commercial poultry sector, which produces chicken meat and eggs for the domestic market.
Because this strain of HPAI is spread by wild birds, it’s unlikely we will be able to keep it out of New Zealand over the long-term or eradicate it once it establishes in the wild bird population.
But we can reduce the impact.
The Ministry for Primary Industries (MPI) is working with the Department of Conservation, health agencies, the poultry and egg industries and local government agencies to prepare for the potential arrival of HPAI and limit the impacts to birds, people and businesses.
Representatives from MPI, the Poultry Industry Association of New Zealand, and the Egg Producers Federation recently visited the United Kingdom to learn from colleagues who have been responding to this strain of HPAI since 2022.
We heard that putting strong biosecurity measures in place before HPAI arrives will reduce the impact and minimise spread among commercial flocks, and that swift action from the first detection can alleviate suffering and reduce the risk of further deaths.
Our work with industry in planning for its arrival in commercial poultry involves looking at six key areas: depopulation, disposing of dead poultry, decontaminating commercial facilities after infection, movement controls, surveillance and tracing, and the possibility of vaccination for commercial facilities. Actions taken would depend on the infected species and location.
A key focus now for industry is ensuring farmers and growers have robust on-farm biosecurity plans in place before an incursion. This has the potential to protect poultry flocks from infection.
If commercial poultry flocks do become infected with HPAI, it will be important to act quickly to minimise animal suffering and the risk of further spread to other flocks.
As with any serious outbreak of an animal disease, there is no easy solution and difficult decisions have to be made.
In New Zealand, the Animal Welfare Act 1999 and the associated codes of welfare for layer hens and meat chickens include requirements for the humane destruction of birds when depopulation is required for disease outbreak. Any decisions taken in response to HPAI in New Zealand will comply with these requirements.
Early detection of HPAI will be key to responding effectively and minimising the impact on both native birds and poultry. Avian influenza signs vary, but with HPAI, the most obvious sign is several dead birds within a flock.
If you see three or more sick or dead wild birds, report it to the exotic pest and disease hotline on 0800 80 99 66. Sick or dead birds should not be handled. Our investigators will advise you on what action to take.
If your poultry are unwell or there has been an unexpected death of several birds, contact your veterinarian first to rule out more common diseases.