Australia is closely monitoring the H5N1 avian influenza, a virus known for its rapid spread and high mortality rate among birds, which has been making its presence felt globally. The recent death of an elderly man in the United States, the first human fatality linked to the H5N1 strain in the country, has heightened concerns about the potential for an outbreak in Australia.
The man, who was over 65 and had pre-existing health conditions, succumbed to the virus after being hospitalised in December. His exposure to H5N1 came from contact with backyard chickens and wild birds, according to health officials in Louisiana. This incident has underscored the virus’s ability to cross species barriers and affect humans, particularly those with compromised health.
In the United States, the virus has led to a state of emergency in places like California, with dozens of farm workers contracting the virus this year. Despite these developments, the World Health Organisation (WHO) maintains that the risk to the general public remains low. However, the virus’s spread to every continent except Australia has experts like Professor Bob Doneley, a veterinary science professor at the University of Queensland, convinced that an outbreak down under is not a matter of if, but when.
Professor Doneley assures that Australia is well-prepared to mitigate the impact of H5N1, with the necessary skills to contain it already in place. The question on everyone’s mind is: How could H5N1 reach Australian shores?
The virus, which first emerged in 1996, has seen a significant increase in outbreaks among birds since 2020, with infected mammals also on the rise. Honorary Professor Robyn Alders from the Australian National University’s Development Policy Centre has highlighted the potential pathways for H5N1’s entry into Australia. These include migrating wild birds, contaminated individuals, or the illegal movement of animals, animal products, or equipment.
Transmission of avian influenza primarily occurs among birds through direct contact with infected birds, their secretions, or faeces, as well as through contaminated environments such as water, soil, and surfaces. Wild migratory birds can carry the virus over long distances, posing a significant risk of spreading the disease. Human infections, while rare, can result from direct contact with infected birds or environments, consumption of undercooked poultry products, or less commonly, through aerosols generated from an infected bird’s droppings or secretions.
Since 2003, the WHO has reported 939 cases of H5N1 infections in humans across 24 countries, with 464 fatalities. However, these numbers may be underestimated due to insufficient surveillance and diagnostic facilities in many regions. Dr. Margaret Harris, an epidemiologist and WHO spokesperson, emphasises that the case mortality rate is very low, with fatalities primarily among the most vulnerable individuals.
The United States has been grappling with an avian influenza outbreak that began in poultry in 2022, resulting in the deaths of nearly 130 million wild and domestic poultry and sickness in 917 dairy herds. The virus’s ability to infect a wide range of hosts and its spread through the consumption of infected carcasses has heightened concerns. In the US, the primary concern is the high levels of the virus in dairy cattle and poultry, which increases the chances of transmission to humans.
In response to the threat, the Australian government has invested over $100 million in preparation for a potential H5N1 outbreak. This investment is directed towards enhancing biosecurity measures, preparedness planning, and the development and storage of influenza vaccines. The Department of Agriculture, Fisheries and Forestry (DAFF) will lead a rapid and coordinated national response in the event of an outbreak.
What do you think are the biggest challenges in preventing the spread of avian influenza to new regions? We’d love to hear your thoughts in the comments below.
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