Victorian child confirmed to have rare and dangerous H5N1 bird flu

The first human case of bird flu in Australia has been detected in a critically ill Victorian child, as an unrelated outbreak of the disease at an egg farm will force authorities to euthanise hundreds of thousands of chickens.

The sick child returned to Australia from India in March and experienced a “severe infection”, according to the Victorian Health Department, but has since made a full recovery after weeks in hospital.

An egg is examined at Britain’s Pirbright Institute, where scientists are harnessing technology in an effort to combat the threat of avian flu. Credit: Bloomberg

Human cases of bird flu are extremely rare but the disease can be severe. The mortality rate in humans is more than 50 per cent. Testing at the weekend confirmed the child had been sick with H5N1, the highly pathogenic version of the virus.

“Fortunately, this virus, the avian influenza H5N1, is actually much, much less transmissible than seasonal flu,” Victorian Chief Health Officer Dr Clare Looker said on ABC radio. “There are very few cases internationally of this being passed from human to human.”

Looker said authorities were satisfied the child did not pass on the virus to family members.

Authorities have been on alert for a particularly virulent strain of H5N1 ripping through wildlife populations on every continent except Australia.

Fears the virus could evolve to pass between mammals were sparked earlier this year when herds of cows in the US state of Texas were infected with the virus and a dairy worker fell ill. Sustained transmission of avian flu between humans has not been recorded.

The last bird flu outbreak in Australia was detected among poultry in 2020.

On Wednesday, Agriculture Victoria said an egg farm near Meredith had been placed into quarantine after a number of chickens were found dead on the property.

Tests conducted by the Australian Centre for Disease Preparedness at Geelong have ruled out H5N1 bird flu.

An Agriculture Victoria spokeswoman said the poultry had been found to have the H7 strain of avian flu – a less severe strain.

The highly pathogenic H5N1 strain has killed millions of birds worldwide. The virus has spread to mammals including seals in Antarctica.

Jack Gough, advocacy director at the Invasive Species Council, said: “If highly pathogenic bird flu turns up in Australia, the Australian government has assessed that it will have catastrophic impacts on our native birds, and may lead to local extinctions of species like black swans.

“In Antarctica, researchers are already observing mass mortality events never seen before on the continent. Thousands of Adelie penguins and skuas are dying, with some scientists suggesting this may lead to a complete loss of local populations.

Invasive Species Council has warned over the threat to Adelie penguins.Credit: iStock

“This strain of bird flu has also killed polar and grizzly bears, and infected bottlenose dolphins, lions and skunks.

“The potential for environmental damage in Australia is catastrophic, but while our poultry industry has a detailed response plan, Australia does not yet have an equivalent plan for wild birds and at-risk mammals like sea lions.”

The risk of the virus gaining the ability to spread between people is very low, but the scenario could be devastating. Based on 889 human infections since 2003, the disease has a 52 per cent mortality rate.

Dr Frank Wong, a bird flu expert for the World Health Organisation from the CSIRO’s Australian Centre for Disease Preparedness, said earlier this month that Australia remained a hold-out for the disease because of strict biosecurity laws and the fact it wasn’t a major stopover for the species of migrating ducks and geese that carry the virus.

However, a Department of Agriculture, Fisheries and Forestry report recently upgraded the risk of highly pathogenic bird flu arriving in Australia to high. The report said migratory shorebirds, shearwaters and nomadic waterfowl were species that could bring the virus to Australia.

Gough said: “Last year this bird flu killed over 60,000 seabirds and 3500 sea lions within weeks of reaching Peru. Seventy per cent of elephant seal pups born in 2023 have died. In the UK it has wiped out about 30 per cent of the country’s breeding population of roseate terns, great skua and gannets.”

Get the day’s breaking news, entertainment ideas and a long read to enjoy. Sign up to receive our Evening Edition newsletter here.