UK scientists and authorities officers are monitoring an outbreak of chicken flu in cows within the United States in case the virus infects herds in Britain, it has emerged.
Avian influenza has been present in dairy cattle in farms throughout eight states within the US for the reason that finish of March, and traces of the virus have been present in milk for business manufacturing.
US authorities concern that the H5N1 virus, which has swept the globe amongst birds since late 2021, might have been circulating amongst cows for months earlier than the alarm was raised.
Although there isn’t any threat to people from consuming pasteurised milk, shoppers within the US have been suggested to not eat or drink uncooked dairy merchandise.
Defra stated there was no proof that the virus was presently spreading in cattle within the UK, and that the chance to people from the virus extra usually stays low. But scientists working with Defra and the UK Health Security Agency have been monitoring the US outbreak intently and stay “vigilant” to any adjustments in threat to Britain, i understands.
Cases amongst poultry on UK farms and amongst wild chicken populations have been falling in recent months, and the pressure of the H5N1 virus in Britain and Europe is barely completely different to that which has been infecting birds and cattle in North America.
But Dr Tom Peacock, a virologist and fellow on the Pirbright Institute and Imperial College London, stated the US outbreak was “clearly concerning”.
He added: “Mammal-to-mammal transmission in a host with a lot of contact with people is always worrying – and this is probably the largest example of this now – certainly larger than the mink farms, and way more human contact than the sealions.”
The undeniable fact that traces of the H5N1 virus had been discovered broadly in business milk within the US was not a priority by itself as it might be killed off by the pasteurisation course of, Dr Peacock stated, including: “Milk will have dead bacteria and viruses in it as a consequence of pasteurisation.
“The worry is if there are really high levels of virus in the milk then pasteurisation might not be 100 per cent efficient in sterilising it. Several labs in the US are testing that currently.
“It is unclear how applicable the outbreak in the US is to the UK – we do dairy farming quite different here, we also have slightly different strains of H5N1 at this point.
“This was picked up in the US because of milk drop, but there is also respiratory disease associated with some animals – I would have thought those would also have been picked up in the UK if we’d had outbreaks.
“Also H5N1 in birds in Europe is waning at the moment – if it had happened it’s likely it would have happened last winter or the winter before (or the one before that even). If there is a virus strain-specific factor (ie the US has a certain strain in its wild birds that is primed to jump into cows), we haven’t currently seen any evidence that US virus strains have migrated to europe – all the migration has been the other direction.”
A Government spokesperson stated: “We are monitoring reports of highly pathogenic avian influenza (H5N1) identified in dairy in the USA and are working closely with international counterparts to better understand the virus strain associated with these cases.
“These reports do not change the risk level for animals for the UK, which is currently ‘low’ and we have no reason to suspect the virus is circulating in our cattle and nor is this virus strain circulating in Europe.
“Food Standards Agency advice remains that avian influenza poses a very low food safety risk for UK consumers.”
An NFU spokesperson stated: “Here in the UK, farmers are continuing to do all they can to protect the health and welfare of their animals. It remains incredibly important that everyone who keeps animals remains vigilant, seeks veterinary attention if concerns arise and reports immediately any suspicion of notifiable disease.”
The threat degree to wild birds in Britain has just lately been downgraded to “low”.
The US outbreak in cattle additionally brought on one human case of the virus. A Texas dairy farm employee examined constructive for chicken flu after coming into contact with sick animals.
While he solely suffered delicate signs, together with conjunctivitis, the case brought on issues amongst scientists as a result of it’s the first time a human has been contaminated with the virus from a mammal, quite than poultry or different chicken.
The US Centers for Disease Control and Prevention has informed American shoppers that the chance to public well being from the cattle outbreak is low, however that individuals ought to keep away from consuming or consuming uncooked dairy merchandise.
Cattle within the UK will not be routinely examined for avian influenza, but when a farmer suspects a respiratory illness the animals are examined for different viruses similar to Influenza D, which is usually present in cows.
As of 24 April, chicken flu has been present in 33 completely different dairy cattle premises in Kansas, Idaho, Michigan, New Mexico, North Caroline, Ohio, South Dakota and Texas.
US scientists imagine the “spillover” occasion from birds to cows doubtless occurred in late 2023.
Michael Worobey, an evolutionary virologist on the University of Arizona, informed STAT information this week: “The bad news is it looks like this is well entrenched and has been in cattle for a long time and … probably very, very, very widespread.
“We need to just study the hell out of it for starters … and see if we can close the gap on what is happening and what we know.”
