According to data provided to the BBC, the virus that causes avian flu has killed approximately 208 million birds worldwide, with at least 200 recorded cases in mammals.
In the UK, there will be more targeted surveillance and testing of animals and humans exposed to the virus.
The UK Health Security Agency (UKHSA) continues to advise that avian flu is primarily a bird disease, but experts around the world are investigating the possibility of it spreading to other species.
Bird flu 'spills over' to otters and foxes in the UK
JIM WATSON/AFP via Getty Images
The virus has been found in a variety of mammals around the world, including grizzly bears in America and mink in Spain, as well as dolphins and seals, as per the BBC.
The Animal and Plant Health Agency (APHA) in the United Kingdom tested 66 mammals, including seals, and discovered that nine otters and foxes tested positive for highly pathogenic avian influenza (HPAI) H5N1.
Public health officials warned that the mutation in mammals may spread to humans, but the risk to the public is very low.
Cases have been discovered in England's Durham, Cheshire, and Cornwall; Wales' Powys; and Scotland's Shetland, the Inner Hebrides, and Fife.
They are thought to have fed on dead or sick wild birds infected with the virus.
The animals had a virus mutation that made it easier to infect mammals, but there was no evidence of transmission between mammals.
The APHA also stated that widespread infection in GB mammals was extremely unlikely.
Since the latest outbreak began in October 2021, there have been five confirmed human cases of the H5N1 virus, including one in the United Kingdom and one death in China.
A nine-year-old girl in Ecuador was found to be infected with avian influenza A last month (H5).
According to the World Health Organization (WHO), nearly 870 cases of human infection with the avian influenza H5N1 virus have been reported from 21 countries over the last 20 years.
457 of these were fatal.
According to the report, the virus "has not acquired the ability for sustained transmission among humans, and thus the likelihood of human-to-human transmission is low."
The threat posed by the virus spreading is very concerning, according to Dr. Wenqing Zhang, the head of WHO's global influenza program, and the risk has been increasing over the years, as evidenced by the number of outbreaks in animals and infections in humans.
Since the outbreak began in October 2021, the World Organization for Animal Health (WOAH) has recorded nearly 42 million individual cases in domestic and wild birds, according to the BBC.
Almost 15 million domestic birds, including poultry, have died as a result of the disease, and an additional 193 million have been culled.
The new strain places bird flu in "uncharted territory," according to Wendy Puryear, a virologist at Tufts University in Medford, Massachusetts.
Researchers have warned that unless precautions are taken, the disease could spread among humans, as per Nature.
Efforts to keep the new strain from spreading beyond the farm appear to have been "vigorous, comprehensive, and successful," according to infectious-disease specialist William Schaffner of Vanderbilt University Medical Center in Nashville, Tennessee.
Puryear believes that because the variant contains genetic material from gull flu, at least some of its genetic changes occurred in gulls prior to entering the mink farm.
This means that a strain with those mutations is still likely to exist in the bird population.
However, the outlook for human populations remains positive: if the new strain does begin to infect people, health officials will almost certainly be able to produce a vaccine quickly, and the antiviral drug Tamiflu (oseltamivir) can reduce the severity of the disease.
The potential risk to wild animals is greater.
Bird flu has consistently caused high levels of sickness and death among wild birds and mammals over the past year, and how the new variant will affect that trend remains to be seen.
