Bird flu that infected Texas farm worker HAS mutated to spread more easily, CDC reveals - as three pet CATS die from virus and America's biggest egg producer is hit with outbreak

The strain of bird flu that infected a person in Texas has mutated to spread more easily, officials say — amid growing alarm the disease could spread to more people.

The CDC said tests on the H5N1 sample showed it had a mutation that was 'known to be associated with viral adaptation to mammalian hosts' - but insisted the mutations were minor and the overall risk to the public was low.

This mutation was not detected in cattle or in wild birds, with officials saying it 'may have been acquired in the patient during the development of the [eye infection]'. 

Meanwhile, three pet cats have died from bird flu after catching the disease on dairy farms in Texas, according to reports — as fears are raised that infected animals living near humans could spread the disease to people.

And the largest egg producer in the US has revealed bird flu has been detected in its flock, with nearly 2million chickens now set to be culled. There is growing concern that the outbreak on farms could cause supply chain issues or drive up the price of eggs and dairy products.

It comes amid concerns that H5N1 — which has already triggered a pandemic in the animal world — could soon do the same in humans. The EU's Food Safety Agency (EFSA) warned Wednesday that a large-scale bird flu pandemic could be triggered if the virus becomes transmissible between people.

A cat pictured in close contact with dairy cows. Three pet cats on an infected dairy farm in Texas have died after contracting H5N1 (stock image)

Infectious disease experts warn every infection in mammals or humans raises the risk of the virus gaining new mutations enabling it to infect people.

Dr Francois Balloux, an epidemiologist in the UK, warned on X that the situation 'might change for the worse, eventually'.

But he added: 'People not professionally involved in pandemic prevention/mitigation being worried/feeling miserable now won't make any material difference to what may hit us, except that their life would suck, far more than it should.'

Dr Peter Hotez, a virologist at Baylor College of Medicine in Texas, told DailyMail.com that the cases were 'a reminder that avian influenza is circulating and continuously jumping to new mammalian hosts.

'So far, the subsequent jumps to humans are still uncommon and not producing severe illness,' he added, 'but I believe this could change eventually'.

The mutation detected on the virus infecting a dairy farm worker in Texas has been recorded previously, the CDC said — and did not spark a major outbreak at that time.

The change, on the PB2 gene linked to how the virus makes copies of itself, has not been recorded on wild poultry on in infections in cows. 

The above graph shows human cases of avian influenza globally reported by year. The colors represent different countries with the light blue being Egypt and the orange being Cambodia

The CDC said: 'It is important to note that this substitution has not been seen in available PB2 genes from viruses circulating in wild birds and poultry or in the recently described cattle viruses detected in Texas.

'[This suggests that] the mutation may have been acquired in the patient during the development of conjunctivitis.'

Bird flu makes millions of copies of itself within every cell it infects before bursting out to infect other nearby cells. A number of these copies contain mutations, with every new copy raising the risk of a mutation emerging which could help the virus to infect or spread between humans.

Colorado prison inmate becomes first US citizen infected H5N1

The only symptom he reported was 'fatigue for a few days' and has since recovered. However, the CDC reported he is still be isolated and treated with the influenza antiviral drug oseltamivir.

The patient in Texas had a mild infection, with their only symptom being inflammation of the eye. 

The first case of bird flu in the US reported in 2022 in a prison worker also saw the patient suffer only from fatigue for a few days.

There are also concerns over infections with bird flu detected in pets — which raises the risk of the virus being spread to humans.

Yesterday, three pet cats were reported to have died after being infected with the virus on an affected dairy farm in Texas.

So far, seven dairy farms in Texas have reported outbreaks alongside two in Kansas and one each in New Mexico and Michigan. There are also suspicions over another outbreak at a farm in Ames, Iowa.

Cows infected are reported to be 'lethargic', eating less food and producing less milk than previously — although they are not dying from the disease.

At the same time, more outbreaks are being reported at poultry farms — leaving farmers with no option but to cull their birds.

The largest egg producer in the US — Cal-Maine — revealed yesterday it would need to cull 2million birds after the virus was detected in its flock. 

Officials in Michigan are now also urging people to take enhanced measures to protect their flocks. 

This is raising concerns over rising prices of milk and eggs.

Farmers are being required to dispose of milk from infected animals, while egg producers are knocked out of action for months by the culling of their flocks.

In 2022, egg prices surged more than 50 percent in response to the outbreak — with a dozen large, Grade A eggs, priced at $3.59 in November compared to $1.72 at the same time the year earlier. They peaked in January, 2023, at $4.82 for a dozen eggs.

Bird flu started to take off in 2020 after a wild bird flu swapped genes with a version of the virus from domestic poultry.

It spread rapidly via migrating birds and in May 2021 it was confirmed to have crossed the bird-mammal barrier for the first time — after two baby foxes in the Netherlands tested positive for the disease.

One died from the infection, while the other was euthanized because of its symptoms. The route of infection was not confirmed, but scientists said it was likely via eating the carcass of an infected bird.

In January 2022, the first case was then diagnosed in a human — in 79-year-old Alan Gosling from the UK.

The former engineer had contracted the virus from one of the 20 Muscovy ducks he shared his home with — and had only mild symptoms.

Barely three months later a second human case was reported in a prison inmate working on a poultry farm in Colorado.

The patient also suffered from only mild symptoms — 'fatigue for a few days' — and later recovered after taking the antiviral drug oseltamivir.

In November 2022, China recorded the first death from the virus — in a poultry farm worker who was infected with H5N1.

Sporadic cases have been detected since, but experts say the numbers are still much lower than the outbreak in Egypt around 2015 — when more than a hundred cases were detected. 

Bird flu began to spread to domestic birds in February 2022, when the US revealed it had detected H5N1 in a turkey flock.

In that year alone, an estimated 52million birds had to be culled to stop the virus spreading — sending up the price of eggs and chicken meat.

More culling was done in 2023 and again this year, with the total number of culled birds now estimated to be more than 82million.

There are also concerns that the virus could spread into other animals with closer contact with humans after a dog in Ottawa, Canada, tested positive in April 2023.

And there are signs that it is gaining the ability to spread between mammals including seals, after 17,000 pups died at a colony in Patagonia.

Experts said at the time that the animals had been infected with bird flu, and warned that it was likely spreading between animals at the site.