Wildlife Health Australia statement on avian influenza and wild birds
Recent detections of avian influenza in two poultry farms in country Victoria have occurred in the vicinity of the towns of Meredith and Terang.
Agriculture Victoria has confirmed they are dealing with two types of high pathogenicity avian influenza (HPAI) H7 strain virus. The first infected property near Meredith is confirmed to have the H7N3 strain of avian influenza virus and the second infected property near Terang is confirmed H7N9. Work is underway to determine the source and spread of the infection on the poultry farms.
These strains are different from the high pathogenicity avian influenza H5 strain (strain “2.3.4.4b”) that is currently impacting wildlife and poultry overseas, which has not yet reached Oceania, including Australia and New Zealand.
Agriculture Victoria has undertaken immediate action to stamp out the current H7 outbreaks in poultry because of the risks posed to the industry.
In wild birds worldwide, including Australia, low pathogenicity avian influenza (LPAI viruses) are part of their natural virus community and typically do not cause severe disease. In many cases, birds infected with LPAI show no symptoms.
LPAI viruses can be introduced to poultry from local wild birds. The virus can then subsequently mutate from LPAI virus to HPAI virus after circulation within poultry, which is a well-documented occurrence.
Before the current 2024 outbreaks, there have been eight other outbreaks due to HPAI viruses in Australian poultry since 1976, all of which were H7. The previous eight outbreaks were all successfully eradicated.
Wildlife Health Australia provides support to the National Avian Influenza Wild Bird (NAIWB) Steering Group and manages and collates avian influenza (AI) surveillance data from wild birds sampled across Australia by jurisdictional biosecurity agencies, universities and the Australian Government Department of Agriculture, Fisheries and Forestry’s Northern Australia Quarantine Strategy. Confirmatory testing occurs at the CSIRO Australian Centre for Disease Preparedness.
Targeted surveillance efforts for AI continue to focus on sampling from waterfowl and shorebirds, specifically from locations where there is known mixing with shorebirds and where waterfowl are in close proximity to poultry and humans.
General surveillance across Australia is also undertaken and focuses on the exclusion of avian influenza from wild bird mortality and morbidity events.
Despite over 140,000 of these tests being undertaken for avian influenza, to date, no HPAI viruses have been identified in Australian wild birds.
Report significant numbers of dead wild birds or other unusual signs of disease in wildlife to authorities through the Emergency Animal Disease Hotline on 1800 675 888. Reporting will alert authorities to the event so they can evaluate the need for investigation. Further information is at:
https://wildlifehealthaustralia.com.au/Incidents/Incident-Information/high-pathogenicity-avian-influenza-information
Photo © Michelle Wille