The world could be facing its second pandemic in three years as the threat of bird flu rises, the World Health Organisation has warned.
Public health experts say the most recent strain has been found to have jumped from birds to mammals, with reports of the H5N1 strain found in otters, foxes and mink.
If the strain jumps to humans, the world could face potentially another pandemic on its hands.
Meanwhile, Covid-19 still presenting in hospitals and causing deaths.
In a virtual briefing, WHO director general Tedros Adhanom Ghebreyesus urged leaders to take action and monitor the virus where it is suspected in mammals.
While the risk to humans remained low, he said, nations must be on their guard and stay prepared for any outcome.
“For the moment, the WHO assesses the risk to humans as low,” said the director general.
“But we cannot assume that will remain the case and we must prepare for any change in the status quo."
He added that WHO was continuing to work out contingency plans and was in talks with vaccine manufacturers in the event of human cases.
H5N1 has been known to spread to humans, however this has been rare and usually due to close contact with dead infected birds.
The H5N1 strain was first confirmed in the UK on a poultry farm near King's Lynn, Norfolk, in November, according to the Government.
The current ongoing outbreak has been described as the UK's largest ever and has contributed to poultry farmers losing 40% of free-range turkey flocks, according to Richard Griffiths, the chief executive of the British Poultry Council.
The outbreak was found to have spread to minks on a farm in Galicia, Spain, in October and has since been found in nine mammals here in the UK.
Vets said five otters and four foxes were found to have had the strain, with the most recent case being recorded in Powys, Wales, last month.
Health experts say that humans must remain vigilant, as risk of the disease spreading to human populations remains a possibility and a risk until the current outbreak is brought under control.
A WHO report in November found that between 2003 (when the virus was first detected in China) and last year, 868 human cases of bird flu have been recorded, over half of which (456) were fatal.
Royal Society for the Protection of Birds director of policy Jeff Knott said in September: "The severity of the situation and scale of the impact is unprecedented and very, very scary.
"It’s a huge crisis that could turn into a catastrophe unless we get ahead of it."
