World Health Organization warns ‘we must prepare’ for potential human bird flu pandemic as H5N1 avian strain jumps to mammals
The World Health Organization has warned the world must prepare for a potential human bird flu pandemic — after the strain jumped from birds to mammals.
Cases of the strain H5N1 have already been reported in otters, mink and foxes, sparking fears the virus is one step closer to sweeping into humans.
During a virtual briefing today, the WHO’s director-general Tedros Adhanom Ghebreyesus urged nations to monitor infections in mammals closely.
He said the risk of the virus jumping to humans was still low, but we ‘cannot assume that will remain the case and we must prepare for any change in the status quo’.
It comes after the UK reported that its biggest-ever avian influenza outbreak had spilled over to mammals. There was also an outbreak among mink in North West Spain reported last month.
WHO director-general Tedros Adhanom Gebreyesus warned today that the world needs to prepare for a human bird flu outbreak. He is pictured above at the WHO’s global health priorities in 2022
H5N1 has previously been detected in people, but cases have been sporadic and closely linked to close contact with infected dead or live birds.
The virus does not infect humans easily or other mammals.
But reports of infections in mammals have raised concerns that the pathogen could gain mutations that make it easier for the virus to jump to humans, helping it to clear the biggest hurdle that has stopped it from sweeping the world.
Leading experts previously warned that the spread of bird flu poses a global risk until it is brought under control.
The US has faced a major outbreak of bird flu this year, with more than 58million poultry affected across nearly every state in the country and 6,100 in wild birds — approaching record levels for the country.
Seven of the UK’s animal avian flu cases detected were in 2022, including one fox in Cheshire and two in Cornwall, as well as one otter in each of Shetland and the Isle of Skye and two in Fife. Pictured: European otter
Dr Brown said it was ‘difficult to control the disease in wild birds’ but ‘what we can do is effectively control the disease in poultry’ (stock image)
Experts have warned that outbreaks among mink could lead to a recombination event — when two viruses switch genetic material to make a new hybrid.
A similar process is thought to have caused the global 2009 swine flu crisis that infected millions across the planet.
The same biological phenomenon was also seen during the Covid pandemic, such as the so-called Deltacron — a recombination of Delta and Omicron, first detected in France last February.
For decades, scientists have warned that bird flu is the most likely contender for triggering the next pandemic.
This could see a deadly strain of bird flu merge with a transmissible seasonal flu.
The mink outbreak occurred on a farm in Galicia, north-west Spain, in October which housed 52,000 of the animals.
It was only spotted after a sudden surge in the animals dying. Up to four percent died in one week during the course of the outbreak, which was declared over by mid-November.
Farm vets swabbed the minks and the samples were analyzed at a Government lab, where they tested positive for H5N1.
It led to all of the animals being culled, farm workers isolating for 10 days and heightened security measures in farms across the country.
These included wearing face masks and disposable overalls and showering before leaving the premises.
Analysis of samples taken, which were published last month in the infectious disease journal Eurosurveillance, show the virus had gained nearly a dozen mutations — most of which had never or rarely been seen before in bird flu strains.
One was previously seen in the virus behind the 2009 global swine flu pandemic.
In the UK, a December report showed four samples from the infected otters and foxes ‘show the presence of a mutation which is associated with potential advantages for mammalian infection’.
The UKHSA warned that the ‘rapid and consistent acquisition of the mutation in mammals may imply this virus has a propensity to cause zoonotic infections’ — meaning it could potentially spread to humans.
Bird flu outbreak: Everything you need to know
What is it?
Avian flu is an infectious type of influenza that spreads among birds.
In rare cases, it can be transmitted to humans through close contact with a dead or alive infected bird.
This includes touching infected birds, their droppings or bedding. People can also catch bird flu if they kill or prepare infected poultry for eating.
Wild birds are carriers, especially through migration.
As they cluster together to breed, the virus spreads rapidly and is then carried to other parts of the globe.
New strains tend to appear first in Asia, from where more than 60 species of shore birds, waders and waterfowl head off to Alaska to breed and mix with migratory birds from the US. Others go west and infect European species.
What strain is currently spreading?
So far the new virus has been detected in some 80million birds and poultry globally since September 2021 — double the previous record the year before.
Not only is the virus spreading at speed, it is also killing at an unprecedented level, leading some experts to say this is the deadliest variant so far.
Millions of chickens and turkeys in the UK have been culled or put into lockdown, affecting the availability of Christmas turkey and free-range eggs.
Can it infect people?
Yes, but only 860 human cases have been reported to the World Health Organization since 2003.
The risk to people has been deemed ‘low’.
But people are strongly urged not to touch sick or dead birds because the virus is lethal, killing 56 per cent of people it does manage to infect.