Highly pathogenic avian influenza
[Shore birds - Image - Guy Weerasinghe]
Page updated 5 July 2024
Avian influenza detected in Victoria, New South Wales and the Australian Capital Territory - May/June/July 2024
NSW
On 19 June 2024 the NSW Government enacted its emergency biosecurity incident plan in response to the confirmed presence of high pathogenic avian influenza (HPAI), serotype H7N8 in samples from a mixed barnyard and free-range commercial egg farm in Greater Sydney.
On 23 June the NSW Government confirmed a second detection of high pathogenic avian influenza, serotype H7N8 in a broiler farm in Greater Sydney. Further information and updates can be found on the NSW Department of Primary Industries avian influenza page.
The AVA have provided a Liaison Officer (AVA-LO) to the NSW DPI to assist in facilitating two-way communication with the veterinary profession regarding the NSW HPAI response. The AVA-LO will regularly meet with DPI to receive updates on the HPAI situation and response, serve as a point of contact for veterinarians to raise concerns or ask questions of DPI, and assist DPI in disseminating HPAI information to veterinarians. If veterinarians have any concerns or questions to escalate with DPI regarding the HPAI response, please contact AVA Senior Advocacy Officer Liz Gemes at Liz.Gemes@ava.com.au.
VIC
In May 2024, Australian Government has enacted its emergency animal disease response plans to support the Victorian Government as it leads the response to the detection of high pathogenicity avian influenza (HPAI) at eight Victorian poultry farms.
Information updates can be found on the Agriculture Victoria Avian Influenza web page.
ACT
The ACT government has confirmed a second site in the ACT has tested positive for high-pathogenicity avian influenza (HPAI), H7N8 strain.
The positive result (H7N8) was detected in backyard chickens at a residential property in the quarantine control area around the original infected property.
The first detection, on 27 June 2024, was transmitted to the ACT from New South Wales via the transporting of eggs and associated materials for commercial grading. Testing confirmed the presence of the high-pathogenicity avian influenza (HPAI) H7N8 strain, and established a link with an infected site in New South Wales.
Further information can be found on the ACT Biosecurity Alerts page
Background
Avian influenza is a global viral disease of birds and there are many strains of the virus that cause infections of differing severity, and all bird species are considered vulnerable to avian influenza. High pathogenicity avian influenza (HPAI) viruses are associated with severe disease and high mortality in poultry. HPAI H5N1 clade 2.3.4.4b is the predominant strain causing recent outbreaks globally.
Avian influenza viruses (both low pathogenicity and high pathogenicity strains) have also been known to infect other animal species overseas. Spill over infections of the H5N1 strain of HPAI virus in non-avian animal species such as pigs, tigers, leopards and domestic cats have been reported in some countries.
Australia’s largest outbreak of HPAI viruses (H7 subtypes) occurred in Victoria in 2020, and after successful eradication Australia was free of HPAIs since February 2021. However, ongoing outbreaks of H5N1 globally have increased Australia’s level of risk for incursions of HPAI viruses of global concern. Migratory birds returning to Australian shores annually between September and November may introduce HPAI viruses.
Avian influenza is a national notifiable emergency animal disease (EAD) and any unusual bird deaths must be reported to the Emergency Animal Disease Hotline on 1800 675 888. This number will connect you with your state or territory’s department of primary industries or agriculture.
Latest updates:
For the latest updates and further information about HPAI visit:
The Wildlife Health Australia website: https://wildlifehealthaustralia.com.au/Incidents/Incident-Information/high-pathogenicity-avian-influenza-information
The Department of Agriculture, Fisheries and Forestry (DAFF) website: https://www.agriculture.gov.au/biosecurity-trade/pests-diseases-weeds/animal/avian-influenza
The World Organisation for Animal Health (WOAH) situation reports website: https://www.woah.org/en/disease/avian-influenza/#ui-id-2
For information on current emergency animal disease (EAD) outbreaks in Australia along with an overview of emerging risks, visit the Outbreak website: https://www.outbreak.gov.au/
Zoonotic disease:
Avian influenza is a zoonotic disease and is potentially fatal to humans. The disease can be passed from birds to humans who are in close contact with poultry or other birds. In Australia, there is minimal risk of people being affected by avian influenza viruses through normal contact with healthy birds, however it is important to always practice good personal hygiene when handling birds.
For more information about avian influenza in humans, visit the Department of Health and Aged Care website: https://www.health.gov.au/diseases/avian-influenza-in-humans-bird-flu
Good biosecurity practices are the key to preventing the spread of avian influenza in poultry species and are critical in combating any incursion. The following information about bird biosecurity is a valuable resource to make clients aware of: https://www.agriculture.gov.au/biosecurity-trade/pests-diseases-weeds/protect-animal-plant/bird-owners
Key information about the clinical signs:
The clinical signs of avian influenza in birds are variable and depend on a range of factors including the virulence of the virus, the species and age of the birds infected, the presence of concurrent diseases, and the environment. In severe forms, such as H5N1 infection, the disease appears suddenly and birds die quickly.
HPAI should be considered as a differential diagnosis in the following scenarios for wild birds:
- Small groups or clusters (5 or more) of sick or dead wild birds of any species.
- Individual or <5 sick or dead wild birds:
- seabirds, waterbirds, shorebirds or birds of prey
- any other bird species with signs of avian influenza infection as outlined below.
Infected live birds may show a wide range of clinical signs, including:
- Neurological signs (ataxia, paralysis, seizures, tremors, abnormal posture)
- Respiratory signs (conjunctivitis, increased nasal secretions, oedema of the head, dyspnoea)
- Gastrointestinal signs (diarrhoea)
- Sudden death
Some species may be asymptomatic or show only very mild clinical signs. In some cases, birds may die suddenly without displaying any clinical signs.
High Pathogenicity Avian Influenza and Wild Birds - Advice for veterinarians and animal health professionals: https://wildlifehealthaustralia.com.au/Portals/0/Incidents/HPAI_Advice_for_veterinarians_and_animal_health_professionals.pdf
Emergency animal diseases: A field guide for Australian veterinarians https://www.outbreak.gov.au/prepare-respond/identify-pests-diseases/emergency-animal-diseases-field-guide
[Eastern Curlews - Image - Guy Weerasinghe]
Useful resources:
Wildlife Health Australia https://wildlifehealthaustralia.com.au/Incidents/Incident-Information/high-pathogenicity-avian-influenza-information
Antarctic HPAI monitoring project: https://scar.org/resources/hpai-monitoring-project/
World Organisation for Animal Health (WOAH) https://www.woah.org/en/disease/avian-influenza/
CSIRO https://www.csiro.au/en/research/animals/veterinary/tracking-avian-influenza
Queensland Government https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/biosecurity/animals/diseases/guide/avian-influenza#
New South Wales Government https://www.dpi.nsw.gov.au/animals-and-livestock/poultry-and-birds/health-disease/avian-influenza
Victorian Government https://agriculture.vic.gov.au/biosecurity/animal-diseases/poultry-diseases/avian-influenza-bird-flu
South Australian Government https://pir.sa.gov.au/biosecurity/animal_health/animal_species/poultry/avian_influenza#
Western Australian Government https://www.agric.wa.gov.au/livestock-biosecurity/avian-influenza
Tasmanian Government https://nre.tas.gov.au/biosecurity-tasmania/animal-biosecurity/animal-health/poultry-and-pigeons/avian-influenza
Northern Territory Government https://health.nt.gov.au/public-health-notifiable-diseases/avian-influenza
Further learning and networking:
Join the Commercial Poultry Veterinarians group: https://www.ava.com.au/about-us/ava-groups/poultry/
Join the Australian Veterinary Conservation Biology group: https://www.ava.com.au/about-us/ava-groups/conservation-biology/
Join the Unusual Pet and Avian Veterinarians group: https://www.ava.com.au/about-us/ava-groups/unusual-pet-avian/
Join the Australian Veterinarians in Public Health group: https://www.ava.com.au/about-us/ava-groups/public-health/
PDF resources side bar:
High Pathogenicity Avian Influenza and Wild Birds - Advice for veterinarians and animal health professionals: https://wildlifehealthaustralia.com.au/Portals/0/Incidents/HPAI_Advice_for_veterinarians_and_animal_health_professionals.pdf
National Wildlife Biosecurity Guidelines – Wildlife Health Australia: https://wildlifehealthaustralia.com.au/Portals/0/ResourceCentre/BiosecurityMgmt/National_Wildlife_Biosecurity_Guidelines.pdf
Avian influenza in wild birds in Australia fact-sheet – Wildlife Health Australia: https://wildlifehealthaustralia.com.au/Portals/0/ResourceCentre/FactSheets/Avian/Avian_Influenza_in_Wild_Birds_in_Australia.pdf