Bird flu has spread to Hawaii for the first time ever amid growing concerns the virus could soon learn to jump between humans.
Ducks and geese on a backyard farm on the island of Oahu, home to the state's capital, tested positive for H5N1 last week, with the virus likely brought in by migratory birds, officials have confirmed.
More than 70 of the birds — including eight ducklings and a swan — have now been slaughtered but officials fear the virus could still be lurking on the island.
Residents are being urged to avoid sick or dead birds and to report them to state authorities immediately.
But they are also being told the risk from bird flu on the island is 'low.'
The spread of H5N1 comes as a teenager in critical condition in Canada was revealed to have caught a strain of bird flu that had mutated to better infect humans.
Researchers raised the alarm over the case, saying it was 'bad news', but added the virus likely gained the mutations after it infected the patient and had not spread to others.
It is not clear where the individual, who has not been named, contracted the virus, but they have now been in critical condition in the hospital for more than a week.
Susan Wilkinson, from Hawaii, owned and ran the bird sanctuary where the virus was detected. She posted a tearful reel online after more than 70 of her birds, including eight ducklings, had to be culled.
Pictured above are ducklings that were rescued and rehomed by the sanctuary at the start of November
Officials have been on the alert for bird flu after the virus suddenly spilled over to cows in 2022, which they said raised the risk it could spread to people.
More than 100million poultry have been infected to date, as well as 10,000 wild birds and 500 dairy herds across 15 states.
Fifty-three people in the US have been infected, mostly farm workers who have close contact with cows or poultry.
Each patient experienced a mild illness involving conjunctivitis, or red eye, and some respiratory symptoms.
No Americans were sick enough to be hospitalized and there are no signs of human-to-human transmission.
Experts warn, however, that every infection runs the risk of the virus gaining mutations making it better able to spread between humans and start a new pandemic.
Hawaii is the 49th state to report bird flu in domestic poultry, with Louisiana now the only one yet to detect the virus.
The infections were detected by Hawaii State Laboratories Division, and confirmed by the National Veterinary Services Laboratories in Ames, Iowa.
The sanctuary's founder, Susan Wilkinson, posted a tear-filled message on Instagram after all of her rescue birds had to be culled.
'I lost 20 of my angels, I didn't know it was bird flu,' she said, fighting back tears, 'I started panicking and thought it was a poisoning'.
'I found out over a week later that it was bird flu, obviously the worst case scenario happened, they came and had to euthanize everybody.'
Ms Wilkinson has been tested for bird flu, but was not infected.
She is now being asked to keep away from birds for two weeks because the virus may still be lurking on her shoes and clothing.
Her sanctuary has been closed to rescue birds for 120 days, which officials say will help ensure the virus has died off before any new birds are introduced.
Ms Wilkinson added: 'I don't want this to happen to anybody else. If you live on Oahu or any of the islands, I need you to take this seriously.
'This is not a government conspiracy, it is not a joke, it is so bad, it is so bad.
'Please quarantine everything, please bleach down everything, be so extra cautious, because this disease comes quick and fast.'
Experts say the virus was likely brought to the island by wild birds migrating from the US mainland for the winter.
Bird flu normally spreads via contact with saliva, nasal secretions and feces from infected birds. It may also spread via droplets expelled during a sneeze.
It is not clear how the virus spread to cows, but experts say this may have been due to contact with secretions from infected or dead birds. It may have then spread between cows via milking machines as well as respiratory droplets.
Experts say every time the virus spreads to a non-bird mammal, this raises the risk that it may gain a mutation making it better able to infect humans.
A post from the duck sanctuary raising the alarm over their birds mysteriously falling sick
Pictured above is a duck which was rescued after being found with a deformed leg. It had to be culled because of the bird flu outbreak
Most of the human cases in the US could be tracked back to infected cattle or poultry.
Only one has an unknown source, a patient in Missouri who tested positive despite having no known contact with wild birds or farm animals. They experienced a mild illness and eye reddening before recovering.
And in Canada, health officials are not sure how a teenager caught bird flu.
The teen had not visited any farms, they said, but had been exposed to dogs, cats and reptiles.
Scientists warned over the mutations after analyzing the flu virus genes that were posted online by Canadian health authorities.
Experts say the mutations likely emerged after the child was infected, as the virus attempted to adapt to its host.
'This is bad news,' Dr Scott Hensley, a microbiologist at the University of Pennsylvania, said in a Bluesky post.
'We need to closely monitor this situation and increase our surveillance efforts.'