Victoria : Credit Wikipedia
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While Australia has been spared dealing with HPAI H5N1, they are wrestling with 7 outbreaks of avian H7 (1 H7N9 & 6 H7N3) outbreaks on poultry farms in Victoria. Media reports suggest in excess of 1 million chickens and ducks have been lost to the virus and culling, although no human infections have been reported.
Like everywhere else in the world, LPAI viruses circulate in Australian birds. Most are considered innocuous to poultry and humans, but when an H5 or H7 LPAI virus spreads among poultry it can sometimes spontaneously mutate into an HPAI strain.
While often these HPAI outbreaks are limited to a single farm, the virus can be inadvertently spread by moving birds, eggs, feed, equipment or personnel between farms. Less commonly, it may be picked up and carried to other farms by local or migratory birds.
First today's update from Agriculture Victoria on what has quickly become Australia's largest avian flu outbreak, after which I'll have a bit more on the history of H7 viruses.
Current situation
Last updated 9 am 17 June 2024
Agriculture Victoria is responding to the detection of avian influenza at 7 Victorian poultry farms. Avian influenza is a viral disease of birds found globally. Virus strains are described as low pathogenicity (LPAI) or high pathogenicity (HPAI).
Six infected properties near Meredith are confirmed to have a high pathogenicity H7N3 strain of avian influenza, and one infected property near Terang is confirmed to have a high pathogenicity H7N9 strain. A comprehensive surveillance program has been in place in the restricted and control areas in order to detect the presence of such viruses.
Restricted and control areas are in place surrounding all infected premises, within both the Golden Plains and Corangamite shires.
All properties have been placed in quarantine and all poultry will be safely and humanely disposed of. The sites will be cleaned and cleared of the infection.
Agriculture Victoria staff are on the ground supporting the affected properties and working closely with poultry owners and industry to contain and eradicate the virus. Tracing is also underway to determine the source and spread of the infection.
Housing requirement
Agriculture Victoria has issued movement controls that include a housing requirement for all birds within the restricted and control areas in Meredith/Lethbridge and Terang.
Under the housing requirement all poultry farmers, backyard flock and bird owners must house or keep their birds enclosed in cages or sheds.
Poultry farmers, backyard flock and bird owners are urged to report any cases of unexplained bird deaths to the VicEmergency Hotline on 1800 226 226.
Food safety
Consumers should not be concerned about eggs and duck meat products. They do not pose a risk and are safe to consume.
Victoria has a secure supply chain, including the importation of eggs from interstate, so the current outbreak has not significantly affected supplies.
Human health
While cases among humans in direct contact with animals infected with highly pathogenic avian influenza viruses are possible, the current risk to the public remains extremely low. Find out more about avian influenza in humans from the BetterHealth Channel.
Compensation in an Emergency Animal Disease outbreak
In the event of a declared Emergency Animal Disease (EAD) outbreak, financial compensation will be available to livestock owners and business that experience livestock or property losses as a direct result of the disease.
Personal wellbeing
Stressful events can cause feelings of worry and unease, especially where there are levels of uncertainty involved, but there are things you can do to take care of yourself.
H7 outbreaks (both LPAI & HPAI) are generally regarded as less serious than HPAI H5 - although the 5 year reign of H7N9 in China (2013-2018) showed us what an H7 virus was capable of; infecting more than 1,500 people and killing roughly 40% of them.
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| H7N9 Epidemic Waves - June 14th 2017 - Credit FAO |
China's H7N9 was admittedly an outlier, as most human infections with H7 produce only mild illness. A few examples include:
- In 2018 a woman in Jiangsu Province, China was seriously infected by an H7N4 virus (see WHO Update & Risk Assessment On Avian H7N4), spending 21 days in the hospital
- NYC's 016 dramatic H7N2 outbreak in cats, and spillover into animal shelter workers (see J Infect Dis: Serological Evidence Of H7N2 Infection Among Animal Shelter Workers, NYC 2016)
- 3 mild cases of LPAI H7N7 in Italy in 2013 (see ECDC Update & Assessment: Human Infection By Avian H7N7 In Italy).
- In 2006 1 person in the UK was confirmed to have contracted H7N3, and the following year, 4 people tested positive for H7N2 – both following local outbreaks in poultry.
- The Fraser Valley H7N3 outbreak of 2004 resulted in at least two human infections, as reported in this EID Journal report: Human Illness from Avian Influenza H7N3, British Columbia.
- And in 2003 a large outbreak of H7N7 (89 confirmed, 1 fatality) in the Netherlands – with nearly all reported cases having very mild (often just conjunctivitis) symptoms.
While H7 viruses remain primarily a concern for poultry producers, their track record in humans is not entirely benign, and we need to control them before they can evolve into a bigger problem.
