Avian Influenza Takes Flight to Sub-Antarctic Regions: A Concern for Australia.

A sub-Antarctic King Penguin unexpectedly turns up on the shores of South Australia, drawing large crowds of curious spectators. While a fascinating and rare opportunity to witness such a creature, it raises questions as to why it arrived and draws a lot of concern given the current panzootic spread of avian influenza, and the potential impact on our commercial poultry industry and unique birdlife.

Avian influenza, commonly known as bird flu, is a highly contagious viral disease, that comprises the avian strains of the influenza A virus. Regional outbreaks have occurred over the past decade, which include both low pathogenicity (little to no disease) and highly pathogenic strains (HPAI). These cause high levels of morbidity and mortality in poultry and wild birds. The most recent outbreak, commencing in 2021, saw the rapid spread of an avian influenza strain known as HPAI H5N1, via migrating birds, decimating wild birds in the UK, Europe, South Africa, the Americas, and parts of South America.

Declared a panzootic (or animal pandemic) by the World Organization for Animal Health (WOAH), to date, infections have reached more than 67 countries and have affected more than 200 species of wild birds and half a billion commercial birds. In the past year, the virus has mutated with spill over to some wild mammals, including foxes and bears, and decimated seal populations in South America. Oceania (Australia, New Zealand) and Antarctica were the only continents free of the disease until 23 October 2023, when the first case was confirmed on Bird Island, in the sub-Antarctic region, killing hundreds of elephant seals and brown skua birds and kelp gulls.

This unexpected transmission of the virus to these remote and ecologically sensitive areas poses unique challenges and potential risks not only for wild bird and seal populations in Antarctica but also raises the risk of transmission of this devastating disease to Australia and New Zealand.

The Spread of Avian Influenza:

Avian influenza is primarily a disease of birds, caused by influenza A viruses. The virus is typically transmitted among birds through direct contact with infected birds, their droppings, or contaminated surfaces.

While most strains of the virus do not infect humans, some, like H5N1 and H7N9, have been known to cause severe illness and, in some cases, death in humans.  In the current pandemic, 14 human cases have been reported worldwide, with all having close contact with infected birds. WHO reports no change to the risk of sustained human-to-human transmission; however, monitoring for any genetic change in transmissible continues.

The sub-Antarctic regions, known for their harsh climate and isolated ecosystems, were once considered relatively safe from the threat of avian influenza. However, recent detection of the virus in these areas indicates a potential shift in the dynamics of the disease. This raises the risk of its spread to our region and the risk of further genetic mutation.

Factors Contributing to the Spread:

Migratory Bird Patterns: Migratory birds play a crucial role in the spread of avian influenza. These birds travel vast distances, connecting different parts of the globe. Changes in migratory patterns, possibly influenced by climate change, may be contributing to the virus reaching sub-Antarctic regions.

Climate Change: The effects of climate change are altering the landscape and ecology of many regions, including the sub-Antarctic. These changes may create more favourable conditions for the survival and transmission of avian influenza.

Concerns and Challenges:

Impact on Wildlife: The sub-Antarctic regions are home to diverse and unique ecosystems, with many species of birds, seals, and marine life. The introduction of avian influenza poses a threat to these populations, potentially leading to declines in local wildlife and disruptions to the delicate balance of their ecosystem. Loss of a food source like elephant seals would have impacts along the marine food chain.

Logistical Challenges: Responding to and managing outbreaks in these remote regions poses significant logistical challenges. Limited infrastructure, harsh weather conditions, and the sheer distance from testing facilities complicate efforts to control the spread of the virus. The reality is that the spread of this virus to Antarctica would significantly increase the risk of spread to Australia.

Human-to-human Infection: Current scientific knowledge of these viruses suggests that contemporary Avian influenza A(H5) viruses have not yet acquired the ability to sustain transmission among humans. Human-to-human transmission is thus currently considered unlikely.  All human infections caused by a new subtype of influenza virus are notifiable under the International Health Regulations (IHR, 2005). If HPAI/ H5N1 was to gain access to Australia and take hold of commercial poultry industry or large flock of wild birds, the risk to humans may increase for those working in close quarters. Further genetic spillover to pigs may also increase the risk to human infection.

Impacts to Australia:

Should HPAI/H5N1 make its way into the wild bird population of Australia, our unique birdlife will be at severe risk, with swans, geese, ducks, and shorebirds being the most susceptible. Horses, pigs, dogs, and cats are also susceptible and would need to be protected from infected birds.

Australia’s Preparation: Australia is considered free of HPAI/H5N1, as this virus type has never been detected in our wild bird populations. Considering the current panzootic event, Australia is conducting increased wild bird monitoring through the National Avian Influenza Surveillance Program and the Australian Centre for Disease Preparedness (a WOAH Collaborating Centre for Avian Influenza).  Avian Influenza is a notifiable disease within Australia, requiring national parks and wildlife groups, and commercial operators to report suspected or confirmed cases and implement effective biosecurity measures.

Your Avian Influenza Plan: What we have observed from the ongoing outbreak of Varroa mites in commercial bee operations is that more needs to be done proactively by organisations and commercial operators to prepare for these rare yet high-consequence events. As part of the planning, ask the following questions:

• Are we receiving adequate updates from animal surveillance networks?
• Are we equipped with the knowledge and resources to monitor the signs of this disease on our property effectively?
• Do we have criteria established for our early-stage response to a suspected case, onsite or in our area
• Have we evaluated the potential impacts and identified control measures to reduce risks to poultry and staff?
• If you rely on protein or egg production for your business, have you identified an alternative product that you could access should your supply chain change?
• Have you drafted communications that describe immediate actions to staff, stakeholders, and customers?

The emergence of avian influenza in the sub-Antarctic regions is a stark reminder of the interconnected nature of our planet's ecosystems. It underscores the need for global collaboration in monitoring and addressing the spread of infectious diseases. As scientists, policymakers, and local communities grapple with the challenges posed by avian influenza in these remote areas, proactive measures, research, and national cooperation are essential to safeguard Australia’s wildlife, commercial operations, and food security.